Talk:Melanin
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Melanin in Plants
[edit]The article does a nice job of pointing out that melanin is ubiquitous in the animal kingdom (except in spiders), but is much too silent on the question of whether melanin is found in plants. This might be a good starting point for someone who wants to do non-original research on this topic: http://www.madsci.org/posts/archives/2009-05/1241451642.Bt.r.html —Preceding unsigned comment added by 71.221.125.125 (talk) 16:11, 22 December 2010 (UTC)
Exposure
[edit]Decreased UV exposure would result in lower melanin production, but what would happen to the existing melanin? Would it be dissolved? If a tanned person stayed out of the sun for months or years, would he become pale?
- Hi I have white spots on my skin and I was wondering if eating carrots would help me get rid of these. I have gotten them befor and stayed out of the sun as much as possible and they went away and now I have gotten some more but this time they won't go away no matter how much I stay out of the sun.
If you have any ideas to help please let me know. My email address is oreo@iland.net thanks Laura
- I recommend you see a doctor.-Anonymous
- Wikipedia is not a medical facility, but a dictionary! -FredrikM
- Wikipedia is not a place to seek medical advise, but nor is it a dictionary. Wikipedia is, believe it or not, an encyclopedia. -- Hadal 16:03, 22 Jul 2004 (UTC)
Protection from disease
[edit]There is something which would appear to be missing from this page. Melanin protects against skin disease - white soldiers in vietnam were more prone to skin infections than black soldiers. People in africa who live in jungles (in the shade!) are generally darker than those who live nearer the equator. Eskimo's are exposed to higher concentrations of UV than people on the equator (due to the reflection from the snow), yet are not as dark. These point towards skin colour being determined at least as much by prevelance of skin infection as it is by exposure to UV. Pog 22:29, 7 February 2007 (UTC)
Also, The reference to light skinned people being 10 times more likely to get skin cancer than dark skinned people refers to a website which refers back to this article! Where's the original source linking skin cancer incidence to skin color
Observation
[edit]It is estimated that this color evolution in an immigrated populace takes approximately 10,000 years to complete.
If this is true, then wouldn't Native Americans that lived in northern Alaska/Canada and Tierra del Fuego have evolved lighter skin by now? To my knowledge, the Americas have been populated for about 10,000 years and for the most part, have the same skin hues. Something must be incorrect... --Bletch 22:39, 17 Oct 2004 (UTC)
- Maybe it was selective breeding? :P lysdexia 00:27, 24 Nov 2004 (UTC)
Hi, not as simple as all of that. Melanin and pigments play a big role in many, many different things in the animal kingdom (see chromophores, for example, in squids, octopus, colour in birds, etc, for communication, social/sexual interactions, etc). Not only for UV protection, although it certainly does is some species. The exact mechanisms of evolution and their causes are very difficult to test and prove, particularly in human populations. Humans are highly polymorphic, and some reasons for skin colour/eye colour/"tallness" selection might be more related to sexual/sociological preferences/practices than a straightforward biological reason... On the other hand, "Evolution" implies the derivation of one species to another one, but not really an "adaptation" or "selection" of specific traits in a certain "isolated" population. It's not the same by any means...Evolution is by far more complex than that...Achaya (talk)
Melanin Theory and melanin in biotech research
[edit]See my recent additions to Black supremacy for some provocative info re the melanin as a superconductor, Melanin Theory, and also for brief references to melanin in biotech. I think all this should be included this article. I'm thinking of doing a separate article on the Melanin Theory in conjunction with (or, possibly, separate from) the Cress Theory on Color and Confrontation. People think Minstrel show is potentially explosive. It oughta be interesting to see the reactions to this on Wiki. deeceevoice 12:01, 5 Feb 2005 (UTC)
- http://www.csicop.org/si/9201/minority.html Wareware 01:12, 6 Feb 2005 (UTC)
I've seen the article on "scientific illiteracy" to which the above link connects. In that particular context, I've already noted that the Melanin Theory has little credibility in mainstream thought in Black supremacy. I'll likely do something similar here -- just in greater detail. In any event, Melanin Theory certainly bears mentioning in this article on melanin -- pro and con.
I could insert more information on melanin here as a superconductor, but -- again -- I'd like someone, perhaps more familiar with the subject than I, to do so. As it stands, this article is far too limited and addresses melanin pretty much only in the context of skin pigmentation. It needs to be broadened and brought into the 21st century. Research into nanotech and plastic electronics applications has been ongoing for some time now. [In fact, I think the 2000(?) Nobel Award in science went to people involved in this kind of research.] I've already inserted information in the Superconductor article on melanin -- but only a brief blurb. Hopefully, the more technically knowledgeable will flesh that out also (no pun intended). I left one contributor to Superconductor a note soliciting input. Unfortunately, most of the major contributors to Superconductor are anonymous -- but, hopefully, someone with some expertise in the field will drop by there and here. deeceevoice 03:38, 6 Feb 2005 (UTC)
Oh, goodness! One cognitive glitch, and all these changes! Anyway, I meant to say "semiconductor" -- not "superconductor." (See talk in Black supremacy for more information. And the additions regarding melanin are actually in organic semiconductor. I still intend to do a section on Melanin Theory here and, if no one else does it, a section on melanin research and biotech applications -- one of these days. deeceevoice 12:18, 6 Feb 2005 (UTC)
Cleanin' It Up
[edit]I fixed up the beginning a little to add some information about what melanin actually is. I also deleted a lot of irrelevant verbal diarrhea from the end. This article is garbage. It needs a lot of work. Babajobu 18:38, 12 Feb 2005 (UTC)
- I've restored the section on melanin and race bias. There are people who think it's a fit topic -- and an important one -- for this particular article. You seem to think so, too. Otherwise, I don't think you would have stuck the sentence about bias on the end of the introductory information. If you have constructive comments, please offer them -- but "verbal diarrhea" is not helpful. Nor is deleting a section wholesale with nothing constructive to offer in its stead. deeceevoice 19:10, 12 Feb 2005 (UTC)
- The section on social and rase bias is psychotic. It's about as relevant to an article on melanin as a lengthy discussion of the biochemical properties of melanin would be to an article on the KKK. I saved the first sentence because I think some mention is warranted of the the fact that variable skin melanin distribution has an impact social organization. But a wacked-out, meandering diatribe that includes expostulations on the comparative prevalence of various race-based ideologies, the structural context within which such ideologies are expressed, comparisons of different country's hierarchical structures, et cetera et cetera et cetera ad nauseum??!! Holy Sh1t!! You gotta be kidding me!! But hey, keep it. I'll stay out of the ethnic pissing contests, and leave them to those who get off on such things. In fact, I think you should expand that section. Maybe add some pictures of lynchings. As for me, I'll throw down the beginning of a section on eumelanin. As for the link between Parkinson's and melanin concentration...I've not heard of any such thing...regardless, melanin concentration in the substantia nigra and in the skin are not correlated. Norwegian albinos have the same melanin concentration in the substantia nigra as do Ghanain non-albinos. Babajobu 02:03, 13 Feb 2005 (UTC)
As someone said recently, "take a chill pill." This section has been substantially restored. Other contributors clearly believe a brief discussion of race bias is in order in connection with melanin; it simply makes sense and existed unchallenged since early October. But, gee, all of a sudden someone black decides to contribute -- and the subject is somehow suddenly no longer relevant? And no one is saying here that melanin concentration in the skin and Parkinson's disease are related; I don't know that they are. (I searched for info on the Internet, but couldn't find anything.) But keep in mind this is not an article about melanin only in the skin, but about melanin, in general. That Parkinson's is marked by a degeneration of melanocytes in the substantia nigra is a medical fact -- and, in fact, is one of the hallmark characteristics of the disease. So, the link to Parkinson's is also restored. deeceevoice 09:37, 14 Feb 2005 (UTC)
- This is an article on melanin and its properties. The prolonged discussion on race bias, racism, various kinds of supremacy belong in each of their articles, respectively. The article on race already has a dicussion on various kinds of apartheid, so it's extraneous to write even more of that here. No need to drag on this "verbal diarrhea." A mention about them and links to the related articles, which both have more in-depth discussion and relevancy, is enough. What's so hard to understand? Wareware 10:49, 14 Feb 2005 (UTC)
My ability to comprehend is not the issue; we have a disagreement. Apparently, other contributors to this article thought the information worthy of inclusion -- as do I. Will not get into a revert war over this. I'm confident that as time develops others will agree that color bias warrants more than the truncated treatment of the last edit. I'm patient. I can wait. :-p deeceevoice 12:02, 14 Feb 2005 (UTC)
There are no melanocytes in the substantia nigra. The melanin in the substantia nigra is a byproduct of dopamine metabolism, because dopamine is synthesized and utilized in the SN and a form of melanin is one of the metabolites of this process. Because there is no melanocyte-mediated production of melanin in the SN, levels of melanocyte activity as observed in skin color don't correlate with what's going on in the SN. Parkinson's disease is a result of breakdown in dopamine synthesis and metabolism. It has nothing to do with melanin in the SN, except that depigmentation of the SN is a consequence of failure to go through the process of dopamine metabolism. I would be open to expanding the "race" section of this article...it just needs to be more tightly relevant. Babajobu 14:37, 14 Feb 2005 (UTC)
So, you've stopped your scatologic ranting, 'eh? :-p Thanks for the clarification. I knew (because I read it recently online; other than that, I don't know squat about melanin & Parkinson's) that dopamine produces the melanin in the substantia nigra and that iron binding to the melanin has something to do with the disease process. But it didn't dawn on me that melanin actually could exist without the presence of melanocytes, that it is actually localed in the neurons themselves in the substantia nigra. But that's precisely why I've been hoping that someone with expertise would contribute. It does seem, however, that -- at least according to what Wareware contributed in the black supremacy discussion -- that there is a suspected correlation between darker skin pigmentation and a resistance to Parkinson's. If you have other information, though, please contribute it where appropriate. deeceevoice 18:45, 14 Feb 2005 (UTC)
- Yeah, well I enjoy ranting but have gotten to do ever-so-little of it thus far on Wikepedia because of the whole infernal "Wikiquette" thing. I couldn't resist the opportunity to indulge a little. :) Here's the dilly (or part of it) on dopamine, melanin and Parkinson's. Dopamine and melanin have very similar structures, and dopamine metabolism produces a form of melanin called "neuromelanin," which is different from eumelanin, pheomelanin, et cetera, but still certainly a melanin. Neuromelanin gradually accumulates in the neurons of the substantia nigra throughout a person's life. Kids have very little, elderly people have lots. When people get Parkinson's they start losing their neuromelanin, and their SN goes pale. The fairly recently-published histology and pathology books I'm using just take it for granted that the loss of neuromelanin is basically a side-effect of dopamine depletion. But I may have been a little too confident in assuming that that's the final word. I just checked the National Library of Medicine website and a bunch of new research is turning up more immediate connections between neuromelanin and Parkinson's than had been suspected. Also, it looks like they're also getting promising results in studies on therapies that involve endocrine manipulation of neuromelanin. Still, all of this specifically involves neuromelanin in the dopaminergic neurons of the SN, and I haven't personally learned, heard or run across anything stating that there is any connection whatsoever between skin melanin and Parkinson's. But I guess the take home message for me is that there is more going on here than I realized, so I can't write off the possibility that there is also--though I can't imagine how--some emerging connection between neuromelanin/Parkinson's and a person's skin melanin levels. Anyway, as you say, this article is about melanin generally, not just skin melanin in humans, so regardless the Parkinson's link is legit. Babajobu 19:57, 14 Feb 2005 (UTC)
Actually, what you've just stated is what I'd already read on the Internet before adding info re melanin and Parkinson's to both melanin or black supremacy. In contributing info on melanin as a semiconductor/ neurotransmitter, it occurred to me it might play a role in Parkinson's, so I looked it up. I did my research. I simply misspoke in spelling of the "degeneration of melanocytes" in the substantia nigra in the discussion. The info in both articles is actually correct; I chose my words carefully, because I realize I'm way out of my comfort zone in writing about such things. But it seemed interesting and certainly provocative enough to mention. deeceevoice 20:14, 14 Feb 2005 (UTC)
- Yeah, interesting it certainly is. I think I'll pick a related abstract at the NLM website and link to it at the end of the article. Later when I have time I should add something on neuromelanin to the "different types of melanin" section. Babajobu 21:11, 14 Feb 2005 (UTC)
- I have to agree, the end here really has nothing to do with Melanin. The "Similar examples can be found in Brazil's highly socially color-stratified society; and, in the U.S., segregation, institutional racism, and internal "color consciousness" on the part of members of some ethnicities." is irrelevant, there is a article on Human skin color, which links to the this page on the chemical melanin. The chemical melanin never had a political/sociological view, it was unbiased, as it is an unconscious amino acid. Human skin color, however, has that nice word human in the title. And humans are huge on their political/sociological views. So I am erasing the "Bias in human societies" section. I should mention again that there are two links to Human Skin color (the proper article for this information), it's the first link under the Human section and in See also. — Preceding unsigned comment added by 66.62.194.227 (talk) 07:05, 13 July 2012 (UTC)
List of To Do's
[edit]This list was included in the article, so I've preserved it here. If anyone is interested in expanding the piece, here are some suggested areas of interest to contributors: To be covered:
- eumelanin
- phaeomelanin
- Melanin Theory
- possible role of melanin deficiency in deafness and Parkinson's disease
- incidence of melanoma by "race"
deeceevoice 19:10, 12 Feb 2005 (UTC)
Reorganization: crappy, but maybe a start
[edit]All of a sudden I was looking at the article, and I thought, "Shiznitz...this could end up being a really good article." If we ended up with good coverage of 1) melanin in humans 2) melanin in other forms of life 3) the emerging technological applications of melanin, and 4) an interesting and relevant "race and social" implications of melanin...well, that could be an extremely good article. I threw in the bare bones of that kind of structure, but collapsed the first two sections into a single "biology" section. Anyway, I was just playing around with ideas, obviously go ahead and make any changes you like or revert it back to the old structure. But I do think that four-pronged structure has potential. I think I'll go tinker around with it a little more.Babajobu 22:30, 14 Feb 2005 (UTC)
As far as the race section: I have some ideas about things that I think would be interesting and relevant here...I also suspect that ultimately more people will join deeceevoice's side and the "broad social" stuff will win the day and be put in the race section. Even so, I think that there are other, tighter race issues that really should be included: what is the extent of melanin's role in skin tones and color? How much do other determinants matter (e.g, carotene, vascular density in skin, etc.)? How much is it a simple matter of melanin concentration, and how much do relative proportions of different types of melanin matter? How much do melanin concentrations influence subjective assessments of race, vs. other variables like facial bone structure, et cetera. Obviously melanin would have to be the focus of all this, rather than the other variables, but some comparative assessment is worthwhile, if any reliable ones have been made and are out there to be used. Anyway, I don't know what the hell I'm talking about. I don't have time for any of this sh*t. I'm never coming back to wikipedia again. See ya' later, suckaz. Catch ya' in another life. Babajobu 22:59, 14 Feb 2005 (UTC)
- See ya. Wouldn't wanna be ya! :-p Actually, it's not as quite as crappy as you may think. But the subsection on melanin in other life forms is completely unnecessary. It essentially repeats info in the opening paragraph and is wa-ay too short to stand on its own. I won't delete it, because it includes a little bit of new info (what the hell are protista?) that I'm too fried at the moment to try to incorporate into the lead para (as it should be). And the renaming of the subhead on melanin and race and social bias to read simply "Melanin in Society" is just incredibly bland utterly meaningless; it says absolutely nothing. If your intent is to gloss over this subject and avoid the related issues as much as possible, you've succeeded. Wikipedia definitely can do better than that.
- I also don't like the way you've renamed the section I began on "Physical properties and applications." When I added those items to the "to do" list and the info re the previously completely overlooked area of melanin biotech/nanotech research, I was hoping people would add to the info and not simply tinker with the wording of the subhead. There is a lot more that can be added. Melanin research is apparently booming. And then there are the applications in the less exciting, more pedestrian area of cosmetics, that at least bear mentioning. How 'bout "Physical properties and technical applications"? I like that better, since the info I added introduces the properties of melanin that are of particular interest in areas of biotech. (Since I didn't do the cosmetics part of it, I didn't make ref. to already presented info re melanin's ability to protect against solar radiation.)
- Thanks for your contributions, but don't let the doorknob hitcha.... :-p deeceevoice 03:24, 15 Feb 2005 (UTC)
I'm back for a sec...I agree that the headings were bland, and that it makes no sense to have a separate section for "melanin in other forms of life" when there is only one sentence on the topic. I was trying to define the basic categories into which the article should be broken down. The headings were merely descriptive, and--even if the article goes on to use the four categories I was thinking of--clearly the section names would need to be more interesting than "melanin in this area, melanin in that area", et cetera. So I changed the physical properties section back to your title, which I agree is better. As for race, I already let y'all know my thoughts on the original race section, and I deleted it once. But that's it. I'm not interested enough in the race issues to battle over the content of the section. Certainly I don't find affluent Americans' obsession with their luxurious "ethnic identities" and their rich-man fantasies of their own persecution and oppression (in the southern hemisphere every year six million children under five years-old starve to death: now that's opression, and it's got nothing to do with the fantasyland of rich, persecuted/oppressed Americans) to be worth any effort to "gloss over it," or obscure it or whatever. What's ridiculous is harmless. So in that spirit I've changed the title of the race and social section to something that more effectively broaches the fantasies Americans have about the social catastrophes in their own country. Babajobu 11:05, 15 Feb 2005 (UTC)
- Grumble, grumble, grumble! Clearly, you have an axe to grind -- and it bores me. You will note that the subsection on melanin-based racial and social bias treated South Africa, India and Brazil, as well as the U.S. And you cannot tell me that apartheid, India's caste system and Brazil's favelas aren't real misery -- or that those societies (and others) are not marked by entrenched systems, still, of disadvantage and privilege based on skin color. Nor can you tell me that race-based discrimination and deprivation still are not pervasive here in the States; they are, indeed. FYI, there happens to be no Richter scale for human suffering, misery and deprivation; those things, though somewhat relative are highly personal and subjective. Unlike you, I don't presume to measure one group's suffering against another or discount one person's suffering in favor of another. A hungry child is a hungry child. Families without healthcare or adequate incomes or adequate shelter suffer, regardless of their location in the world. I'll leave such arrogance and insensitivity to others. deeceevoice 11:31, 15 Feb 2005 (UTC)
Oh, one more thing...I put the section on melanin in other forms of life because I think in a complete article on melanin, that should be included. The one sentence already there is just an inadequate stub. Anyway, if you don't think the melanin article needs a section on its role in other forms of life, then go ahead and zap that mug. Incidentally, I like Americans, loved the time I've spent there, and like the ones I've met on Wikipedia. I was just making observations that are obvious to most southern hemisphere folk, but apparently invisible to Americans. Middle and working class Americans, who are in actuality hopelessly rich from any sane historical perspective, can't spend 17 billion dollars a year on ice cream, billions more than that on cosmetics, and so on, and then expect the rest of to buy their sappy, silly stories about how tough they got it. "Ethnicity" is just another Yankee luxury, nothing more. Babajobu 11:18, 15 Feb 2005 (UTC)
- "'Ethnicity is just another Yankee luxury, nothing more." What?. Ethnicity/color bias is a prominent factor in determining who the haves and have have-nots are in lots of countries other than the States. And to pretend otherwise is the height of intellectual dishonesty and just outright stupidity. And how naive your perception is of America and Americans! No, the streets here aren't paved with gold. Try telling a couple of hotel workers with two children who can't find a one-bedroom apartment for under $1,300 a month how good they have it. Or a marginally literate couple whose children attend a failing school. Or someone in an efficiency apartment on a fixed income whose rent ceiling is $5,000/month. Or a hungry, battered, elderly veteran who sells secondhand books lined along the sidewalk in front of a neighborhood supermarket, because he can't make ends meet, otherwise. Or a tattered, homeless person digging into trash cans along the street, scavenging for food. I'd really love to see that. Go ahead tell them how their disadvantage and deprivation are somehow a figment of their "Yankee" imaginations. If you had a conscience, you'd hang your head in shame first. deeceevoice
- Responding to your "Grumble, grumble, grumble" post: Okay, I'll take the accusation of "arrogance and insensitivity." Maybe you're right. And I really have no gripe with Americans...if anything I'm a bit of an Americaphile. But I agree with you that a hungry child is a hungry child...this is why I insist that we do need to make comparisons between the suffering of different groups. There is no point in doing it in retrospect as a form of "We had it worse" one-upsmanship between groups...but we do need to do it in the present, so that we know where to devote out energies and efforts. How else would we decide where to start? What's worse? A 33 percent under-five mortality rate in Botswana, or comparatively (to Botswana) mild poverty in India (to say nothing of the U.S.)? We have to be able to answer that question. We gain nothing by pretending they are equivalent. Anyway, we've gotten off topic. And I don't want to bore you. Babajobu 12:02, 15 Feb 2005 (UTC)
- Now responding to your first "ethnicity is not a luxury post" (I'll respond to the expanded one after): Yes, absolutely, race, ethnicity and so on are important factors in many places to the extent that they're all wrapped up with "who gets what." The irony a much bigger than any of those things is the sort of inward myopia that allows ordinary Americans to blow obscene, unimaginable quantities of money on frivolous luxuries while south of the equator children are starving for lack of a few cents. This myopia belongs to Americans generally, and crosses all ethnicities. I don't know that the worst white, black, red, yellow or orange bigot in America has dehumanized his "ethnic" enemies as much as each American dehumanizes a Southern child by choosing a cute purse or whatever over that dying child's life. Babajobu 12:02, 15 Feb 2005 (UTC)
We are not in disagreement on the points you raise -- but none of that has anything whatsoever to do with your purposeful obtuseness (and vandalism) w/regard to addressing melanin-based bias in this particular article. Your comments have denigrated the subject -- and that's what I'm sticking to here; I intend to keep on point. Get a grip and stick to the subject at hand. deeceevoice 12:30, 15 Feb 2005 (UTC)
- I just wrote this response to your "America is not perfect" post, and then saw your new entry. Okay fine, as I said I accept that I am not well-positioned to write the "melanin and race" section. Or even to contribute to it. It's all yours. I'll just add my response here, and then I'll shut up on the topic. Here's the response: I know America is not perfect. No human society will ever be perfect. But America's problems (and I still have difficulty not putting quotes around the word) are utterly negligible compared to problems elsewhere. That's not something to be ashamed of...you all have the right to be proud of it, no one handed it to you. And there's no large ethnic group in America that can't claim a major role in contributing to that success. And as hard as this is to grasp for Americans--and I'm glad you mentioned homelessness, because it's a topic I happen to know something about--a homeless person in America, undesirable as his circumstances may be in many respects, has free access to resources that are unimaginable in any developing country. He has public hospitals that will see him for free. Yes, he has to sit and wait a long time, and the care he gets isn't as good as other Americans'. But having to sit and wait in a hospital emergency room for just-okay medical care is not the same thing as dying a gruesome death for lack of an innoculation that cost 25 cents. The homeless American has access to public benefits that may seem inadequate to him, but that are beyond the realm of comprehension to someone in, say, Bangladesh or Sudan. This doesn't mean he has a good life...just that he has more opportunities and resources than people experiencing a far deeper, more extreme poverty elsewhere. There is a cosmic gulf between America and the world's South. The internal disagreements in America--ethnic, economic, whatever--just pale in comparison to that gulf. That's why you drive everyone so goddamn crazy--even when they like you, as they usually do. Babajobu 12:46, 15 Feb 2005 (UTC)
I can't help how others react to the ongoing push for a better life for everyone in this country. The implication is American citizens should be happy and just shut the hell up because there are others so much worse off. Heeding that advice woud have meant that African Americans would never have stepped up and changed the course of history of this nation for the better and set an example that has fueled all sorts of struggles of marginalized peoples for human rights, for self-determination and equality. That's unacceptable. Besides, I don't think that's what drives people crazy about this nation at all. I think they admire us for that.
What, I think, drives other nations crazy is when that drive to perfect a just and egalitarian society takes the form of self-righteousness, hypocrisy, paternalism and insularity: Bush and Condie Rice's determination to "spread democracy" throughout the Middle East; the U.S. pummeling other nations in the UN w/regard to human rights violations and then Abu Ghraib; Bush's push to spend billion of dollars for "democracy" in Iraq, but we here in the District of Columbia don't even have voting representation in Congress; the U.S. being the richest, but stingiest, nation when it comes to share of GNP devoted to foreign aid; its consumption of a ridiculous portion of the world's natural resources and its failure to ratify the Kyoto accord; the absolutely maddeningly, happy abysmal ignorance of Americans about the rest of the world, because they're too comfortable and complacent (and often arrogant) to give a shyt -- and on and on and on. And then there's just the sheer galling presence of a nation so gottdamned rich among those of such grinding poverty.
But like I said, I have no control over how other people of other nations react. As an activist, I deal with issues of social, economic and political justice all the time; and that's my answer. I'm one of those striving for perfection -- or, at least, something as close to justice as I can get. Resentfully picking at scabs and comparing suffering for the hell of being argumentative, to me, are pointless endeavors. And, again, all this has absolutely nothing to do with the subject at hand and your obtuseness with regard to dealing with melanin and race bias -- one of most important driving forces in the shaping of the world today as we know it. deeceevoice 13:20, 15 Feb 2005 (UTC)
- Heh...well, most of my American friends would fall on the "liberal" side of the American political spectrum, and ironically the thing I've argued with them about most is the current American foreign policy. You would disagree with me, too, so I won't even start. So all I'll say is this: the world will survive Condi Rice and George Bush. And when Condi Rice meets European foreign ministers--stodgy old white men who represent countries in which the decision to let in a thousand black refugees kicks off national hysteria about the swamping of "our culture"--well, it's a titan meeting pygmies, Condi Rice being the titan, and the European FMs the pygmies. And no one would ever have had to guess whether it would have been Europe or America that produced Rice, Powell, et cetera. Anyway, my point is that the "drive for justice" among Americans in the U.S. has, in my opinion, reached a point of diminishing returns. Basically, I'm saying that you should be applying that drive abroad. Government aid is one thing, but Americans give nearly 2 percent of their personal income to charity (compared with say, the French who give .4%) But most of that privately-given money is given to domestic causes. I think it's time you guys looked around, said, "well, this is pretty damn good, now maybe its time to spread the love abroad." I don't know, obviously, you'll do what you like. I think you wield power as Americans, whether you have lots of melanin or no melanin. The internal divisions/preoccupations are now just distracting you from more meaningful use of your resources, in my personal opinion. Babajobu 14:10, 15 Feb 2005 (UTC)
You probably don't know jack about the complexities of America's internal problems, so I'll overlook your ignorance about "diminishing returns" -- but not your presumptuous arrogance. Don't speak on what you don't know. There is lots that can be done domestically that hasn't even been attempted, let alone tried and failed. And it doesn't make any damned sense to give up on the serious problems confronting us in our own backyards in favor of dealing with those abroad. The problems this nation faces internally are far more than "distractions." The primary responsibility of any nation is seeing to the basic needs of its own citizens first.
Your approach is simplistic and ill-informed. The fact is, it's not an either-or choice; there's no dilemma between domestic priorities and international responsibility. After all, I was the first to bring up the stinginess of this nation, the disparity between America's GNP and what this nation gives in foreign aid. And there's one helluvah difference between American militarism in the service of imperialism and paternalism and getting up off our asses and dealing with the appalling situations in Sudan and elsewhere. It would seem precious little has been learned from Rwanda. Bush, Sr., and Clinton have made PSAs here for appeals for Americans to contribute tsunami relief, but I've heard little to nothing about Sudan, or the looming famine in Ethiopia. And I'm not one to wax all sentimental about the likes of Condi Rice. The woman is just plain scary. Bad foreign policy with a brown face is still bad foreign policy. Lies coming from the lips of Condi Rice are still lies.
You aren't here, and I don't think you have a clue what's going on in this nation w/regard to the numbers of families without access to healthcare or affordable housing, homelessness, people going hungry, the crappy public education system, the gang violence, the growing HIV-AIDS problem among "minorities." These are not "distractions." They are pressing problems that demand attention.
My comments on your changes stand; by and large, they have not been improvements. Quite the contrary. And, again, none of this justifies your obtuseness and puerile vandalism in dealing with melanin and race bias in this article. deeceevoice 14:39, 15 Feb 2005 (UTC)
- Yes, I have agreed with you several times now that I shouldn't contribute to the melanin and race bias section. I'm more familiar with the problems in the U.S. than you think. With all due respect, I think the difference is that I see them within a broader context. All Egyptian pyramids look pretty damn formidable when you stand underneath them, and I'm sure people who live in Luxor think theirs are enormous. But once you've been to Giza, well...Luxor looks a lot different. Gotta run, take care. Babajobu 15:02, 15 Feb 2005 (UTC)
Nope. We each have our own visions of a broader context. IMO, the problem is you've placed yourself in the position of defending an indefensible, immature, presumptuous and arrogant rant. If you had a true understanding of the nature and scope of domestic problems in the U.S., you would not have called them "distractions." deeceevoice 08:24, 17 Feb 2005 (UTC)
In light of subsequent comments by Babajobu, the section on melanin and bias has been restored -- with some editing. deeceevoice 14:57, 8 Mar 2005 (UTC)
Why the hell would we need to have a lengthy description of what racism, racialism, black supremacy, white supremacy, all sorts of "caste" system on a page on melanin the biological molecule? What's this crap? In light of Babajobu's comments? He didn't even support this idea of writing so much crap and not much science on it. Give me a break. The readers should be referred to the individual articles, which there are plenty of, instead of treading through this dreg. Wareware 18:41, 8 Mar 2005 (UTC)
You are mistaken. This page is about melanin as a broad subject -- not just about the "biological molecule." Babajobu later acknowledged that a discussion of this subject was probably warranted and that he was probably not the person to deal with it. He admitted he was simply venting in his earlier comments. The readers are, indeed, referred to other articles via the links provided when the various subjects are mentioned in the body of the text. To truncate the treatment and then give two or three examples is inadequate. A brief -- and it is brief, even shorter than it was before -- discussion of the role of melanin in race (or ethnic) and social bias is completely within the purview of this article. The information is restored. deeceevoice 19:09, 8 Mar 2005 (UTC)
- I don't think anything can get through your thick skull that's so preoccupied with race, racism, racialism, and all sorts of related crap. Look, what is the point of mentioning the apartheid systems (already covered in racism article) and redheads/blondes with melanin. Because the readers are directed to more thorough information in their respective articles, there's no need to explode into more discussions about them. If they want to know more about racism and skin color, just go to their own pages. Most of people who want to know more about melanin care about the molecule of melanin, not about apartheid in India or South Africa. It's been really difficult to reason with you. I'll quit arguing and just revert whatever extraneous info you come up with. If you're so adamant on projecting your race-related vent then why don't you go ahead and make an article on Melanin (social bias/racism/racialism/apartheid/etc). Give me a break Wareware 03:40, 9 Mar 2005 (UTC)
Wrong again. When one erroneous argument fails, you resort to censoring. It is not for any of us to presume to know what someone wants to know about a subject, or to determine what we want them to know, based on our own predilections, and then tailor an article accordingly. Once again, this is an encyclopedia, the purpose of which is to treat subjects in their entirety. The information provided on melanin in race and social bias is important, as color bias has been one of the most important, driving forces in human civilization. The information as it is presented is minimal, listing, in text form with links for the reader desirous of reading more, various examples of color-based bias. It does not treat them exhaustively, nor does it explain how these constructs function, but it does provide options and direction to the reader.
Your complaints accompanying your last two reversions are groundless. The section on race and color bias makes perfect sense, and I have now tweaked the two sentences on "black supremacy" even further.
One more revert, one more intemperate comment, and this matter will be referred for mediation, and you will be recommended for suspension. deeceevoice 06:42, 9 Mar 2005 (UTC)
- Racism is important, but it doesn't belong in every article. Let us keep the short version. pstudier 06:57, 2005 Mar 9 (UTC)
- Hear that deeceevoice? Oh my god! Big Black Momma is coming to report me for suspension! Holy jesus I'd better run. Seriously, you're not getting the message here, but insist on inserting every racism/racialism/black supremacy/white supremacy every chance you get. Why don't you re-read my previous comment, as you seem to have totally missed the message Wareware 07:11, 9 Mar 2005 (UTC)
Wareware, keep in mind that the average Wiki user doesn't follow me from article to article to read my contributions. Each article to which I contribute should be viewed separately and the merits of my contributions judged as one would judge those of any other contributor. My interest is my interest, and my intent is my intent. I am no different from a music aficionado following his or her interest to articles related to that broad subject. Wareware, you keep harping on my "preoccupation" with matters of race. My stated intent is to bring a black perspective to Wiki articles -- which is sorely lacking on this website. And you seem to have a problem with that. Not my problem. The preoccupation, in fact, is yours; because you repeatedly follow me around Wikipedia like some lap dog to snipe at my contributions, becoming increasingly belligerent with each post. Get some common sense, some self-respect. Get a life. deeceevoice 09:53, 9 Mar 2005 (UTC)
PStudier, "every article"? Only one article -- this one -- is currently under discussion. And, indeed, in an article on melanin, treatment of color-based racial/ethnic and social bias should be mentioned, and in a meaningful and informative way that provides sufficient context and also links to pertinent topics -- not simply in passing. deeceevoice 09:57, 9 Mar 2005 (UTC)
- I guess I should've made myself clear. Your preoccupation is inserting pov information on race, not some innocent neutral black perspective. Your ridiculous edits on Afrocentrism is the prime example of it. And the crap about each article should stand on its own. Well, that depends what kind of contributor is writing those articles. You gotta be kidding me to have made that statement. But hey, I need my daily dose of comedy, and your various edits and comments provide plenty of those. And that I'm increasingly belligerent? Just take a look at the talk pages of Afrocentrism and see who was repeatedly requested to act with some basic civility? It's rather pathetic of you to accuse somebody of being belligerent, you know. Wareware 10:16, 9 Mar 2005 (UTC)
I could bring up all kinds of garbage here about your conduct and your racist remarks. But I won't. Try to focus, Wareware. Under discussion is this article, this discussion thread and your conduct herein. And if there's something POV in this article, then point it out. Straighten up. deeceevoice 11:31, 9 Mar 2005 (UTC)
You know what, you need to come up with some good reasons on why the hell you're reverting the article, but I guess that is out of your league. And you've accused me of being a racist for I don't know how many times now; I've even predicted on several occasions that you'll do such. The only remotely racist remark I've made so far is the one on africans and apes, and that's after you made a fool of yourself by saying Asians have small penises and made a long and biting derision out of it. That was a long time ago and you're kidding yourself if you say you can bring up all kinds of my purported racist conduct. God, the probability of your accusing someone of being racist approaches one on almost every discussion, it's funny and pathetic at the same time really. Wareware 16:56, 9 Mar 2005 (UTC)
- No, I said no such thing. You're delusional. First, you assumed I was a male and made a comment about the size of my genitalia, and I simply suggested that, as an Asian, you might not wanna go there. What you read into it is your business. :-p Hey, I'm not the one who started talkin' under people's clothes. lol (A lesson. If you don't wanna go there, don't open the door.) And it was then you made the classic, racist reference to apes and black folks. And "racist" is a word I use very sparingly; this discussion thread is the first place I've characterized your comments as "racist" -- the very first. If you recall, at the time of the dispute, I simply laughed at your ignorance and called you "my misguided Asian brother." Your memory needs a little help. Got ginko? :-p
- What? Still no example of my POV contributions to this article? Not surprising, because there isn't one. My contributions, as usual, have been substantive and useful.
- Ah, but all this "he said, she said" is tiresome -- and it comes off like whining. You should understand very well why I've made the reverts. I've explained my actions thoroughly -- while you, on the other hand, simply have complained ad nauseam about your perception of my cumulative comments in various forums over time. Like I said, my concern is this forum, now. Specific, though brief, mention of various forms of melanin-based color bias in human societies across cultures and continents is useful information; and it should be included so that readers have specific references for further reading, should they be inclined to follow up. If they're not interested, they probably won't bother to read past the subhead; that's one of the reasons it's there in the first place. And that's their choice. But at least they have a choice. deeceevoice 17:16, 9 Mar 2005 (UTC)
- You still haven't explained any logical reason besides more bullshit. "The reders have a choice" to continue reading or not. Well, that kind of reasoning justifies just about every and any adddition of extraneous info. I can insert all sorts of crap into articles and then say "well, the readers can choose what to read or what not to read." And "melanin-based color bias." That craks me up. Jesus, you're like one of those people who like to add more adjectives and make new terms to make something sound bigger than it really it is. For your information, human skin color is based on melanin. Can you tell me any other __-based color bias? Also, color bias is the most likely cause for and is almost racism itself, so the readers should be redirected there, unless you tell me that blacks are discriminated against because they have thick lips, so more information should be spent here on melanin-based racism. Can you tell me the difference between "melanin-based color bias" and any other kinds of racism? Or are you just playing with words here? Really, why is your skull so thick? Why insist on inserting so many references to racism? Are you on a crusade or something? This is not black-o-pedia or something for you to add substantial racism-related vents when the articles call for none. Look at the article on human skin color, it's got a even shorter mention of race relations than this one. I'm thinking about doing it that way and get rid of the subhead altogether like that. Why don't you add more racist info to lips, hair, eyes, evolution, apes, human skin color, melanin, melanoma, sickle cell disease, crainiology, human intelligence, and so forth? Look, when a reader wants to know about racism, he would most likely search for, say, racism, racialism, prejudice, discrimination, miscegenation, racial superiority, affirmative action, racial intelligence, and so on, but NOT melanin. You're not the one with at least some logic here, and I don't think it's a "black" thing, so why don't you open your eyes and clear up your brain, and stop reverting. Wareware 18:51, 11 Mar 2005 (UTC)
- I'm beginning to wonder if you even know what "racism" is. There is absolutely nothing racist in the section you seem determined to excise. Nothing. Further, no. I read your changes and, when I consider them to be an improvement, I incorporate them. Your first reaction, on the other hand, in every single article you follow me to is to mindlessly revert everything --including the obvious typos I correct. Seemingly, your raison d'etre on Wikipedia is to follow we around like some deranged stalker. How sad. deeceevoice 20:23, 11 Mar 2005 (UTC)
I have no idea what thought process led to the inclusion of 'melanin based bias in society' in this article. Ranting about racial inequality is not appropriate under the topic of melanin. There is definately scope for the relationship between 'skin melanin concentration' and 'race' to be explored, but that does not extend to social issues like racism and skin colour bias. The entire section needs scrapping and re-written by someone without bias or social agenda. Deeceevoice - if you feel compelled to write about the social issues surrounding skin colour, do so in a more appropriate place (perhaps under skin color). Remember, this is an article about melanin! Tim123 321miT (talk) 13:51, 6 March 2010 (UTC)
Polyacetylene
[edit]There's a note that this article should include material from Polyacetylene. That article is a stub and I'm not sure how if belongs in this article. Does anyone know what needs to be merged into this article? RJFJR 02:08, Mar 10, 2005 (UTC)
Melanin is biological polyacetylene, in much the same way latex of Brazil is polyisoprene. They're two names for the same family of polymers, but one word is used by biologists and the other by materials scientists. I put the merge there (somewhat naively) thinking that materials scientists like myself should know more about the vast quantity of work that's been done on polyacetylene by biochemists. Really, the page should just become a redirect to this one...I'll try to take care of that sometime in the next week if I have the energy. Anyone interested in electronics applications should read this article.--Polyparadigm 06:30, 10 Mar 2005 (UTC)
It's clearer to me now. (The external link nicely shows the polyacetylene chain). So PolyacetyleneS is being used to refer to any molecule with a long chain of carbons with alternating single and double bonds, even if has a lot of side bonds (even ones that form rings with the back bone). The Polyacetylene chem-stub needs a diagram (prefereably, or at least a good description of what happens when you polymerize acetylene). The Melanin article might benefit from drawings of the two monomers. (Anyone have an opinion on whether this would clarify or would it just distract?) Depending how the structure is drawn the polyacetylene backbone may or may not be obvious.
- Polyparadigm, I inserted a link to organic semiconductors at the bottom of the page, which I inserted a while back. I also wrote the paragraph referring to electronics applications, with a reference to "plastic electronics," a field for which there doesn't appear to be an article yet. Perhaps it exists on Wiki under another name? If not, perhaps you'd want to tackle the subject. I certainly don't know enough of the field and what's happening research-wise to do so. If there is an article on the subject, but under a slightly different name, perhaps you can insert an appropriate, working link in its stead? Thanks. deeceevoice 17:34, 11 Mar 2005 (UTC)
Chemistry
[edit]There seems to be a lack of chemists on Wikipedia...
Poly(acetylene), like all polymers, is named for its monomer. The correct notation includes the word poly followed by the name of the monomer surround by parentheses. The word polyacetylenes is a widely accepted term for a class of polymers that are derived from acetylenes. It is completely incorrect to refer to all structures containing alternating sp3/sp2 (single/double bonded) carbons as a polyacteylenes. Latex is most certaily not a polyacetyele. It is a polyisoprene, which is a completely different classifcation of molecules. Isoprene is a naturally occuring 5 carbon unit used in biological systems to construct molecules ranging from vitamin A to the compound that gives rise the smell of oranges and lemons (limonene, the enantiomers of which smell like orange and lemon). It is extremely difficult to teach someone who has not completed a college organic chemistry series how to classify polymers and exactly how incorrect it is to refer to a poly(isoprene) as a poly(acetylene) because to classify a polymer you have to do some retro-synthetic analysis.
In the definition of melanin it states that melanin is comprised of indolequinone, and dihydroxyindole carboxylic acid units. Neither of these are acetylenes therefore melanin is NOT a poly(acetylene).
Above comment was added by Fearofcarpet
So, is Melanin a organic semiconductor? pstudier 19:25, 2005 Mar 17 (UTC)
Actually, the comment in the above section does describe latex as natural polyisoprene. But it also describes melanin as a polyacetylene. Can someone check the stub at polyacetylene, please? RJFJR 20:21, Mar 17, 2005 (UTC)
-It does refer to poly(isoprene), but seemed to be lumping it into the same category so I wanted to make the distinction. I realize the way I worded it was poor, but I simply meant to draw a contrast between the two. Fearofcarpet 21:26, 17 Mar 2005 (UTC)
I see. Thank you for clarifying. Since you seem to know something about organic chemistry did you happen to look at the polyacetylene stub? RJFJR 21:55, Mar 17, 2005 (UTC)
-I have looked at the poly(acetylene) stub and it needs help, but I don't have the time right now. If someone has the Handbook of Conducting Polymers (which I'm too poor to afford) handy it should have an appropriate discussion of poly(acetylene) in the context of its importance in the field of conducting polymers. Someone brought a sample of doped poly(acetylene) to a seminar (it looks just like metal foil... Very cool) and we snapped a picture which I will upload if I can find. At any rate, though not the first conducting polymer made, experiments with poly(acetylene) probably contributed more to the fundamental understanding of organic semiconductors than any other polymer and deserves more than just a stub. Fearofcarpet 19:55, 18 Mar 2005 (UTC)
- I removed: {{mergefrom}} [[Polyacetylene]] <!--http://www.organicsemiconductors.com/--> because that article is a stub and there is nothing to merge in yet. We may want to add that the melanin has a long chain of alternating single and double bonds, like polyacetylene. RJFJR 11:58, Apr 16, 2005 (UTC)
Interestingly, Roberto Nicolaus, the Italian chemist who originally pretty much characterized the structure of melanin, points out] that polyacetylene is the "simplest melanin" that some fungal melanins are pure polyacetylene, and that all melanins contain the polyacetylene structure.
Further, the discovery history here has been reversed. The winners of the 2000 Nobel chemistry prize got it for the discovery of a high conductivity form of polyacetylene "melanin" and for figuring out the mechanism of conduction. However, both had been done for another "melanin" several years before by John McGinness and his coworkers. Even the first "plastic transistor" (or at least the first organic electronic device) was made of "melanin". Take most melanin and "dope" it with a bit of diethylamine and it looks almost metallic as it dries. 206.180.133.30 16:20, 22 August 2006 (UTC)
See talk:black supremacy for info/links re physical properties ongoing high-tech research
[edit]I'd like to refer those who have an interest in this subject to the talk page of the above-referenced article. I've brought in some additional information regarding melanin-related deafness in mammals, as well more info regarding current melanin research in the fields of quantum chemistry and plastic (or organic) electronics that should appear in this piece. And, yes. Melanin is an organic semiconductor -- a fact which has been known since 1970. deeceevoice 08:20, 18 Mar 2005 (UTC)
Unprotected
[edit]This article has been protected for too long, and in any case there is no discussion here in the past week. Unprotected. --Tony Sidaway|Talk 15:24, 27 Mar 2005 (UTC)
Restoration of disputed text
[edit]For obvious reasons, I feel user Wareware's objections to the disputed language for the section on the role of melanin in race and social bias are groundless and motivated by something other than the quality and thoroughness of this article. With User:Jiang's block removed, unless there is further and substantive objection, the relevant passages will be reinserted within a few days' time. deeceevoice 11:16, 29 Mar 2005 (UTC)
- You asked for comment so I'll put my two cents in. Please read with many grains of salt. While melanin is the pigmentation chemical in human skin, I view this article as chemistry, material sciences and biology. But I view the material you want to add as either psychology or sociology. (Melanin molecules have neither psychology nor sociology, only humans have these). A link to other articles on human's perception of skin color, etc., is appropriate. If the material you are seeking to add already exists elsewhere in the Wikipedia then we don't need to duplicate it here but can just link to that material. This raises a related question: does that material exist in one article or is it distributed through many articles? RJFJR 02:06, Mar 31, 2005 (UTC)
Thanks for weighing in. The problem with your view, however, is that the article is about Melanin -- not the Chemistry of melanin. I don't understand why people don't get that; for me, it's a no-brainer. That's like arbitrarily saying an article titled Dog should deal with only the physical attributes of the animal and nothing else. Wikipedia is an encyclopedia, so the subjects it treats should be dealt with encyclopedically. Melanin-based color bias has been (and continues to be) one of the most important phenomena in shaping world history, in determining who are the haves and who are the have-nots: the trans-Atlantic slave trade, white supremacy and racism, segregation and discrimination in American society, India's caste system, rampant color-based bias in Latin America, colonialism, imperialism, etc., etc., etc.
This may not have anything to do with your reaction to the inclusion of such a brief discussion of the matter in this article, but I have to ask: what is it with white folks and racism -- particularly these folks on Wikipedia? Are they afraid of the issue? Is this a means of censoring subject matter and keeping articles confined to only those matters with which certain people are comfortable? I think a major dose of intellectual honesty is in order here.
If you read the disputed text, it is barely an outline of examples of such bias in human societies. It is a way of mentioning related topics in their appropriate context and an intelligent way of guiding readers to these related subjects (rather than via a rather meaningless, "see also list") without going into detail about any of them. I have to say I think your objection is completely wrong-headed and based on an unjustifiably narrow interpretation of what the scope of this article should be. deeceevoice 06:27, 31 Mar 2005 (UTC)
- From the beginning of the article: Melanin is a polymer of either or both of two monomer molecules: indolequinone, and dihydroxyindole carboxylic acid. Sounds like Chemistry of melanin to me. Most bias in society is not based just on skin color but also on history, culture, etc. Therefore these things should be discussed elsewhere.
- Why do you assume that the people who disagree with you are white folks? pstudier 22:54, 2005 Mar 31 (UTC)
That, it seems to me, is a thoroughly nonsensical argument. Every article must begin somewhere -- usually with the simplest, most basic information and then on to the more complex. That's just simply the way articles generally develop. (WHAT?) If one were to examine just about any article anywhere, it begins with a general statement and then presents additional, more detailed information. (I can't believe I even have to state this.) But to assume that the scope of an article that begins with a simple, introductory fact must be limited to an explication of merely the first one or two statements is patently absurd. Again, there is no rational argument for confining an article on melanin to solely its chemical properties. Further, the article has already breached the confines of chemical properties by discussing "Melanin in human adaptation" -- without dissent. But as soon as one attempts a meaningful, though brief, examination of "Melanin and race and social bias" -- hold up! -- there's a problem. Makes no sense at all.
Something else that makes no sense? Your debatable contention that, "Most bias in society is not based just on skin color but also on history, culture, etc. Therefore these things should be discussed elsewhere." Wrong again. Bias based on things other than melanin should be discussed elsewhere. Melanin-based bias should be addressed here.
Why do I assume that the people who disagree with me are white folks? I don't. Why are you assuming I do? Further, are you assuming that I assumed RJFJR is white? Gee, why assume that? :p deeceevoice 01:33, 1 Apr 2005 (UTC)
- Well, from your above comment: what is it with white folks and racism -- particularly these folks on Wikipedia? pstudier 02:34, 2005 Apr 1 (UTC)
Well, that's what assuming things will get you: wrong again. (After all, I didn't say, "... what is it with you folks...?) Actually, the racist (and he is one; I'm not gonna get into it here) I got into an edit war with about this isn't white or black; he's Asian. Is that all you've got to say about the substance of our disagreement? (Jeeze.) deeceevoice 05:02, 1 Apr 2005 (UTC) No objection of any merit, no comeback. Text is restored. deeceevoice 15:49, 16 Apr 2005 (UTC)
Other functions
[edit]The intro currently includes: ...where, among other functions, it serves as a pigment. Can we list some of these other functions? RJFJR 12:00, Apr 16, 2005 (UTC)
See the discussion in Black supremacy. Forget the claims of Melanin Theory. There's a lot of information presented there with regard to melanin as a mediator of radiation (posing a problem in the dermatological laser treatment of port-wine stains); its absence (in albinism and vitiligo) being linked to deafness in humans and other mammals, and with neurological disease states/neuromotor impairment, such as Parkinson's; as well as links to sites of biotech companies engaged in melanin research. I don't have time to do any of this at the moment, but I've laid out much of the information there -- if anyone is interested enough to investigate. Peace. deeceevoice 15:48, 16 Apr 2005 (UTC)
I'm not entirely sure I should get in to this rather heated discussion, but this sentence struck me as.... not NPOV.
"Because of the pervasive influence of white supremacist values worldwide, prejudice against people with more highly pigmented skin is the most pervasive form of color bias."User:Orporg
- This is merely a statement of fact. In societies across the world, there is a greater tendency to favor lighter skin -- even (and, perhaps, especially) in societies where European influence has been profound, in societies where such standards of beauty are actually antithetical to the peoples themselves. In India in ancient times, for example, dark skin was preferred. After Persian and British influence, the reverse is true. The same with Latinos. The same with the Chinese. The same is true with blacks in many parts of Africa and the diaspora World. Because of European colonialist and imperialist influences, European cultural values have been adopted by other societies, including European aesthetics when it comes to physical beauty. It's why some Asians have eye surgery to remove the skin folds from their eyes. It's why some Latinos and East Indians die their hair blonde and counsel their children not to marry someone darker than they. Same with Jews. It's why some black folks bleach their skin and slice their noses. And the funny thing about all this is that white folks are now rushing to buy bronzing gels (having now finally internalized the fact that sizzling in the sun was giving them melanomas), get butt implants, collagen injections for their lips and rat and tease their hair. Silly (and sad) business -- all of it. deeceevoice 18:01, 7 May 2005 (UTC)
Is there data to support these conclusions? Especially data from outside the West? Also, there must be billions of people (most of China, for instance) who have never had an encounter with anyone from another racial/color group than themselves. How would they be able to practice white supremacism? --Orporg
- Believe it or not, it's not 1800 and most Chinese HAVE seen "whites". Not only does China have a large Caucasoid (read: white) population, there are 1 billion TV viewers in China. As for white supremacism, it is not practised per se, but filtered down influences through the media. But in fact, Chinese have always favoured fairer skin - though darker skin were not discriminated against, merely, um, not as good. Of course this difference in skin colour in native Chinese population is very small, perhaps even smaller than the difference in Northern Europeans and Southern Europeans. Also, since Chinese people in general are as fair as Southern Europeans, the "white" supremacism is not manifest in skin colour, rather, it is in other Caucasoid features (big nose, round eyes, etc.) There are no Wacko Jacko in China. ;) -Hmib 07:50, 24 Jun 2005 (UTC)
Parkinson's disease, prostate cancer, and more
[edit]I'm thinking of removing the reference to skin melanin protecting neuromelanin: this is a single speculative reference on a psychiatry website. I can't find any supporting info in neurology texts or websites, which is the field in which such research would actually be done and such speculations investigated. Plus, the speculation clashes with everthing that is known about the etiology of Parkinson's. And there is a much stronger correlation between, say, prostate cancer and skin melanin concentration than between Parkinson's and skin melanin concentration. Babajobu 06:25, 18 October 2005 (UTC)
The article/abstract from which the quote is taken appears to be learned. Further, I checked on (only) one of the authors, who apparently has contributed to other pieces in scholarly scientific journals. Unless you've published in the field and have kept up with melanin research, I don't think you're necessarily qualified to judge the expertise of a practicing physician and researcher. The quote advances an interesting hypothesis, one which the authors thought significant enough to merit inclusion. Leave it be. deeceevoice 23:59, 20 October 2005 (UTC)
- Well, I'll leave it, but I don't think it belongs. I'm not questioning the author's legitimacy as a psychiatric researcher...but my point is that psychiatry is not the field in which that kind of hypothesis about melanin would be investigated. It's a neurological issue. It's as though we had one quote from neurological paper making a novel suggestion about a dermatological issue. That wouldn't justify our including that comment in the article on skin. Unless we can find at least some evidence that some neurologist somewhere takes this idea seriously, than I don't think it belongs in the article. Babajobu 00:21, 21 October 2005 (UTC)
You're assuming that because the article appears in an online psychological journal, that that is the doctors' field of expertise. An examination of the contents of the abstract, however, reveals that it deals with medical issues outside the field, and -- again -- at least one of the primary investigators has published in other scientific journals -- not dealing with psychiatry. It belongs. deeceevoice 02:50, 21 October 2005 (UTC)
- Pigmentary abnormalities have been observed in psychiatric and neurological illness for decades. In fact, IIRC it was part of the original definition of schizophrenia. For the older history, see "Free radicals and Human Disease" 206.180.133.30 16:29, 22 August 2006 (UTC)
Evidence for adaptive loss of human melanism
[edit]I don't wish to wade into what is a well discussed topic unannounced, but i was thinking of adding some text addressing the issue of whether loss of melanism in humans was due to positive selection for light skin (driven by the vitamin D requirement at northern latitudes) or simply a result of genetic drift (lack of UV pressure on maintaining dark skin). There is some new scholarly literature that seems to shed light on the issue (in favour of the former). Any thoughts? Rockpocket 08:30, 29 December 2005 (UTC)
- That sounds like something you could add under the "Melanin and human adaptation" section. Be sure to cite your sources. — TheKMantalk 08:36, 29 December 2005 (UTC)
- Gone ahead and added the adaptation info with citations. Also cleaned up that section a little to avoid repetition, revised the use of the words "blacks" and "whites" to "dark/light skinned" when refering to people - incorrectly associates race with a skin colour. I also revised the section on albinism and deafness. If one is being pedantic, one could argue the pathology is is not directly related to melanin, as its the lack of melanocytes that causes deafness, not the lack of melanin. Melanin free melanocytes do the job just fine. In the same vein, associating the term 'albino' with deafness is potentially confusing, as true albinos are almost all not deaf. Those who have pigmentary problems and deafness are technically piebald, due to neural crest mirgation problems. Nevertheless, i left the term albino in there as i suppose it could be interpreted as an unbrella term to describe hypopigmentation. I did make clear the role of melanocytes though. Rockpocket 21:09, 29 December 2005 (UTC)
Quotation
[edit]There is a blocked out quotation(s?) about the Scots' low pigmentation levels and African's higher melanin levels under "Melanin and human adaptation" that is cited, but not really in prose. It's just presented in the middle of the paragraph without saying, "according to a recent study by ..." or something to that effect. Yom 08:21, 31 March 2006 (UTC)
- To be honest, that is a remnant of an early version of the article that didn't explain the concepts on pigmentary evolution in greater detail. It doesn't really say anything that is not explaine further down and could probably be deleted now. Rockpocket 17:51, 31 March 2006 (UTC)
Why the reversions?
[edit]Dunc, as an administrator, you know that you are supposed to discuss reversions on the talk page. Or are you trying to trap me into getting banned under the three reversions policy? What is the matter with you? This is flat-out cyber stalking. I also note that you have been censored for similar behavior elswhere and have a history of this kind of out-of bounds behavior.
- Your edits consist of self-promotion because they cite Peter Proctor (yourself). That is not allowed by established community rules. You should make the case for your edits here on the talk page. If they are valid then someone else will make them for you. — Dunc|☺ 15:17, 19 August 2006 (UTC)
- As usual, you cite the rule wrongly. Wikipedia:No original research says
- "Expert editors: "No original research" does not prohibit experts on a specific topic from adding their knowledge to Wikipedia. On the contrary, Wikipedia welcomes the contributions of experts, as long as their knowledge is verifiable. We assume, however, that someone is an expert not only because of their personal and direct knowledge of a topic, but also because of their knowledge of published sources on a topic. This policy prohibits expert editors from drawing on their personal and direct knowledge if such knowledge is unverifiable. 'If an expert editor has published the results of his or her research elsewhere, in a reputable publication, the editor can cite that source while writing in the third person and complying with our NPOV policy.' They must cite reliable, third-party publications and may not use their unpublished knowledge, which would be impossible to verify. We hope expert editors will draw on their knowledge of published sources to enrich our articles, bearing in mind that specialists do not occupy a privileged position within Wikipedia." Pproctor 15:38, 19 August 2006 (UTC)
- As usual, you cite the rule wrongly. Wikipedia:No original research says
Self-promotion
[edit]Your persistant desire to cite yourself is worrying, as it constitutes self-promotion. Self-promotion is heavily frowned upon because it is a tactic used by all sorts of overly self-important net kooks.
So here is the rule: If you want to make a change that in any way might be interpreted as self-promotion, you need to discuss it on the talk page of the article first. If your edit is valid, someone else will do it for you. — Dunc|☺ 15:09, 19 August 2006 (UTC)
- Pot-kettle. In view of your own uncountable rule violations and previous censoring (detailed above), you have a lot of nerve accusing anyone else of a rule violation. Worse, you don't seem to have learned a thing from the experience of being censored. Maybe a concerted campaign involving the numerous people you have messed over and your myriad rule violations will finally force a solution. Were you not a sysop, you would have been tossed long ago. Wikipedia is tolerant, but not that tolerant.
- As for "self-promotion": As usual, you cite the rule wrongly. Wikipedia:No original research says
- "Expert editors: "No original research" does not prohibit experts on a specific topic from adding their knowledge to Wikipedia. On the contrary, Wikipedia welcomes the contributions of experts, as long as their knowledge is verifiable. We assume, however, that someone is an expert not only because of their personal and direct knowledge of a topic, but also because of their knowledge of published sources on a topic. This policy prohibits expert editors from drawing on their personal and direct knowledge if such knowledge is unverifiable. 'If an expert editor has published the results of his or her research elsewhere, in a reputable publication, the editor can cite that source while writing in the third person and complying with our NPOV policy.' They must cite reliable, third-party publications and may not use their unpublished knowledge, which would be impossible to verify. We hope expert editors will draw on their knowledge of published sources to enrich our articles, bearing in mind that specialists do not occupy a privileged position within Wikipedia." Pproctor 15:38, 19 August 2006 (UTC)
Now you're straying off topic, whining about policy and wikilawyering. The guidelines you need here are at Wikipedia:Vanity guidelines. That will take the article nowhere. So,
Please make the justification for your edits here and then someone else will make them for you. — Dunc|☺ 15:52, 19 August 2006 (UTC)
- Again, there is a specific and unequivocal exemption for expert editors in the NPOV section. In case you missed it above, I'll repeat it here:
- 'If an expert editor has published the results of his or her research elsewhere, in a reputable publication, the editor can cite that source while writing in the third person and complying with our NPOV policy.'
- As for wikilawering--as usual, you have the rules wrong. So you can't really complain when I cite the real rules back at you. Pproctor 16:37, 19 August 2006 (UTC)
Darwin's Cat (picture)
[edit]Should be moved down the page, so that it is closer to the paragraph that refers to it. JohnJohn 02:51, 7 September 2006 (UTC)
- Kitty demonstrates the multiple functions of melanin-- skin, hair and eye color, as well as in non-illuminated areas such as the inner ear. Also, "Darwin's cat" is an oblique reference to Schroedinger's cat, another macro example of a quantum process. In this case, this is the strong electron-phonon coupling characteristic of Conductive polymers, which is why they all look black and are called "melanins". In fact, another name for such is polyacetylene, polypyrrole, etc. "blacks".
- English translation-- vibrations of atoms (heat and sound) are strongly coupled with electronic vibrations caused by (e.g.) absorbing light. So, e.g., light or sound energy gets converted to heat.Pproctor 00:27, 30 September 2006 (UTC)
Melanin and development
[edit]I've heard that higher amounts of melanin make a peron's biological development faster, can anyone confirm this?
- Of course no one can prove such a thing. alteripse 23:32, 17 September 2006 (UTC)
- Highly unlikely. During development, melanin is packaged in vesicles called melanosomes inside specialised neural crest derived cells called melanocytes. Having "higher amounts of melanin" in these cells would have very little impact on biological development as a whole. However, it could be the case the genetic variation which leads to more melanin being produced could also effect developmental processes. However, in this hypothetical case, the link between melanin and development would be associative, not a causative. Rockpocket 00:59, 18 September 2006 (UTC)
Well, I thought about this because of a bizzare article I read: http://www.mindfully.org/GE/James-Watson-Racist-Sexist.htm
A nobel prize winner pushing off ideas about pomc being linked to higher sexual promiscuity, is there credibility for this? Also, has there been any correlation found with higher rates of development and melanin, (I mean actual research, I read your reponse) or anything like personality and it's correlation with melanin etc.? And are you saying that your ideas on such a correlation with development are hypothetical?
Also, when I reffered to biological devlopment, I was reffering to things like cognitive, mental, and pubic development, and if there's a correlation between this and melanin levels. Is there any, at all?
Another question, the mainpage mentions how there is no relationship between melanin in the brain etc. and a person's skin color. Does melanin exist in other internal parts of a person's body? Is there a source for that lack of relationship mentioned?
And one last thing, does melanin have a relation to development in other organisms, or any other traits? Ok, so another reason why I'm asking this is also because of these bizzare afrocentrist theories about melanin and the like. I have no idea if deeceevoice is still around to spout this vicious, destructive racist drivel and I'm really amazed there have been so few refutations of this garbage about melanin theory.
- I thought Watson's comments may have been the source of your query. So, although his comments were somewhat inconsidered, he does have a point about POMC. It is an interesting molecule. Let me try and address your questions one at a time:
- There is some indirect evidence linking pigmentation to sexual function, but its important to note that that it isn't the pigmentation itself that is the causative link, but that both pigmentation and sexual function are downstream of POMC signalling (or its derivatives). Consider the strange story of Melanotan. Vic Hruby and colleagues were looking for tanning compounds and, when they did trials of an alpha-melanocyte stimulating hormone analogue (a product of POMC) they found that male volunteers got spontaneous erections (and mild pigmentation effects).[1] So whats going on here? Well, its not entirely clear, but most likely the Melanotan peptide is activating melanogenesis via the MC1R receptor in the skin and stilumating the erection via another related receptor (perhaps MC4R or MC5R) in the CNS or penis. As Watson suggested other products of POMC are endorphins, and thus provide feelings of happiness. POMC's other melanocortin products signal through MC3R and MC4R in the brain to regulate appetite and through MC2R in the adrenals to regulate steriod production. Thus, as a protein, POMC has the potential to influence a lot of different characteristics. I say potential, because natural differences in skin colour in humans appear to have little to do with differences in POMC itself. Instead, other proteins in the signalling pathway appear to influence skin colour (such as MC1R itself, and the very interesting SLC24A5).
- I am not familiar with any modern, peer accepted research has has corrolated human melanin per se with the developmental parameters you mention. This is why i said "hypothetical". Here is an example of a clinical proband that has a mutation in POMC (and thus a pigmentation phenotype) and has various other problems, illustrating how pigmentation and such things as obesity can be linked. However, i'm not aware of reports of such corrolations within the wider (non clinical) population, suggesting, as i said before, that the role of POMC in pigment variation is minor.
- Neuromelanin is not associated with skin colour because the mechanism through which it is made is different. Melanin is found in other tissues including the eye (which is linked to skin colour), inner ear (i don't know for sure if that is linked, but probably is) and in some strange undefined cells on the kidney (again, i don't know if they are linked, but i would guess not). The rule of thumb, i would propose, is that if the cells are neural crest dervied, they would be linked to skin colour, if they are not, they will not be.
- You last query is very interesting: does melanin have a relation to development in other organisms, or any other traits? Thats a good question, and its where Watson's suggestions make some sense. I spent a number of years studying the origins of the melanocortin system to work out how the pigmentary system evolved in humans. To cut a long and complex story short, it appears the a complex two hormone system (MCH and MSH) that strongly regulates background adaptation in cold-blooded animals has been co-opted in humans, to regulate other systems such as appetite, leaving human pigmentation somewhat less dependent on hormonal regulation. Thus, "melanin" (in terms of its production and, more importantly, translocation) correlates with displays of emotion, communication and stress in animals such as fish, frogs and chameleons. However, that link is largely missing in humans due to the delinking of the pigment pathway from the hormones. Moreover, reducing or increasing melanin in these animals does not appear to influence these other characteristics, as both as simply different effects of the same endocrine pathway. If you would like to learn more about this, a read of the chromatophore article would help.
- I don't think there is any evidence whatsoever that increases in human skin melanin have developmental consequences (other than the obvious implications for melanoma). The way I, as someone in the academic field, consider it is like this: from a pigmentary genetics point of view, the differences between black and white pigmented skin, is no more or less significant than the difference between blonde and red hair. Having red hair doesn't make you have freckles or require greater amounts of anesthesia during surgery, but there is a strong correlation between these due to the shared function of the genes involved. Similarly having more eumelanin instead of phaeomelanin doesn't make you anything else other than darker skinned. I suspect there probably is corrolation with other largely inconsequential traits, but certainly nothing as dramatic or regressive as the "destructive racist drivel" you mention. Rockpocket 08:08, 19 September 2006 (UTC)
Wow, thanks for all that! Still, is there any remote credibility, at all, to melanin theory or any of those other black supremacist notions? Also, does the POMC level a person has relate to their melanin level at all? And one last thing, but does melanin affect the appearance of internal organs as well? If so, which ones? And do you have a source for there being no relationship to things like the brain and adrenal gland like the article mentions?
- I'll respond indented point by point, if thats ok. Simply, in my professional opinion, the scientific consensus would hold that there is currently no credible biological evidence that links natural variations of skin colour to a superiority in race. This is partly because human "superiority" is subjective and essentially a meaningless term unless qualified. If you wish to me more specific, you could make an argument that darker skin is "better" in certain situations. For examples, individuals with dark skin would clearly be superior at surviving in Equatorial Africa compared to those with pale skin. If that is the basis of black superiority theory, than so be it. But outside that, there is little that is directly linked to human pigmentation to back up that theory.
- Gross POMC level does relate to melanin ratio in humans (phaeo- or eumelanin). We know if you take it away completely you get pale skin and red hair. However, whether it is a significant contributor to the range of pigmentation seen in the human population is currently not known, though evidence would appear to suggest it is not particularly significant. [2]
- I honestly don't know if the internal organs of people of different skin tones differ. There is no reason i can think that they would, but a surgeon would be able to answer that one for sure. Rockpocket 07:28, 20 September 2006 (UTC)
- Actually, there is considerable evidence for a link between pigmentation and development. The best and first example is Darwin's deaf white kitty, where Darwin even points out the developmental abnormalities. Similarly, oculocutaneous albinism and Waardenberg's syndrome are both associated with developmental abnormalities in (e.g.) the innner ear and eye and their neural connections. My personal opinion is that this is a manifestation of Redox signaling, where redox processes control cellular functions. Another possibility is that this might be related to melanins properties as a rigid-backbone class conductive polymer, rather like the ones in your new color cell phone. Pproctor 13:34, 3 October 2006 (UTC)
"There is some indirect evidence linking pigmentation to sexual function,"
Uh, are you saying that darker skin color/pigment/melanin or whatever is linked to higher sexual function and happiness? That people with darker skin are more predisposed towards those? Are Watson's comments on the sun credible as well?
- No. I am not saying that. I was simply showing that we know that injecting POMC (or something that mimics it) can both stimulate erections and melanogenesis in humans. Thus those functions are indirectly linked by POMC. Is there any evidence this has a meaningful effect in a natural situation? No. None whatsoever.
- His comments about the sun are interesting. People do report feeling better, healthier, happier and sexier after exposure to the sun. Its hard to know exactly why this is, though we know that POMC production can be stimulated by UV light exposure. [3] Clearly there is more to it than just simple sun exposure (or else those that lived by the equator would be feeling great all the time). Its possible that those of different skin tones may produce different amount of POMC on UV exposure, but again, the evidence in humans doesn't really support this as a significant factor [4] Rockpocket 07:28, 20 September 2006 (UTC)
And finally, what of Watson's comments on thin and fat people?
- Is food/appetite regulation (and thus, indirectly, weight) and happiness linked via POMC? Possibly. Afterall, most people can tell you being hungry does not make you happy, and plenty of people would define happiness as a big old chocolate bar. But Watson was simply trying to provoke a reaction by suggesting that there is any evidence that "thin people are unhappy". There is not. And even if there was, the social and cultural factors that influence our obsession with weight would hugely outweigh any genetic links. We are not a slave to our genes, after all. Rockpocket 07:28, 20 September 2006 (UTC)
Uh yeah, this is something else I found strange: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=2636201&dopt=Abstract
This study seems to indicate personality traits with eye color, meaning the pigment in the eye would determine it.... Uh, have you heard of this? Is this study even remotely credible?
- I remember finding that abstract myself a few years ago. Weird, isn't it? I don't know if the data is credible or not as i haven't read the whole paper, but it certianly hasn't been followed up by the community. You can find lots of correlations like this in biology, whether they are maeningful is another matter altogether, and to find that out you have to look for a mechanism. Kagan appears to work slightly off the beaten track, anway. Have a look at this, for example. [5]. So the answer is this one is... who knows? Rockpocket 07:28, 20 September 2006 (UTC)
Heh, wow, alot there. Thanks for answer my questions, I have a few more though:
Is the relation that POMC has to skin pigment independent of sexual promiscuity, happiness and appetite? Do people with different skin tones synthesize different levels of POMC in relation to pigment?
Also, you say that melanin theory has "little" credibility outside of skin coloration against UV rays. What do you mean by little?
Are Watson's comments about alcohol credible as well?
And in that article, it directly quotes a man who says there's no correlation between the lepton in fat people and sexual promiscuity. Still, where did he get this? Is there any correlation whatsoever?
Also, to be honest, the correlations with eye color etc. sound pretty much like bunk to me. I find it dubious to think that a set of melanin genes in the eye could have any effect on a person's personality, sounds pretty new-age to me. Still, thanks again!
Oh, hey, I'm back. I had another question, sorry if I'm grating on you- what is the connection with melanin and dopamine?
Melanin and Development-Part 2
[edit]Actually, there is evidence for a link between pigmentation and development. The best and first example is Darwin's deaf white kitty, where Darwin even points out the developmental abnormalities. Similarly, oculocutaneous albinism and Waardenberg's syndrome are both associated with developmental abnormalities in (e.g.) the inner ear and the eye and their neural connections. Melanin is a stable free radical. So, this might be a manifestation of Redox signaling, where redox processes control cellular functions. Another possibility is that this might be related to melanin's properties as a rigid-backbone class conductive polymer, rather like the ones in your new color cell phone. Pproctor 13:41, 3 October 2006 (UTC)
Melanin and Ionizing Radiation
[edit]1. See this, probably deserves some attention...
2. The statement "It absorbs harmful UV-radiation and transforms the energy into harmless amounts of heat through a process called "ultrafast internal conversion". This property enables melanin to dissipate more than 99.9% of the absorbed UV radiation as heat..." is nonsense. The fraction of absorption always depends on density and thickness. Any real material absorbs 99.9% of uv radiation if the layer is thick enough as transmission goes down exp(-d*alpha), where d is the thickness and alpha the (non zero) absorption coefficient.
Melanin in fungi
[edit]Radiation-loving fungi: the perfect space food? [6] Appearently, some fungi uses melanin to harness radiation. The test used Gamma Rays and it worked. Thanks, CarpD 5/24/07.
Neuropeptide?
[edit]"Melanin is a biopolymer and a neuropeptide." How is melanin a peptide if it's composed of aromatic ring oligomers? This must be a mistake. Peiter 17:59, 24 May 2007 (UTC)
- The problems go much deeper than that. All the stuff about polymers that cannot be supported by reliable references has to go. I'm going to start with some articles that talk about melanin polymers such as Impact of Melanin on Microbial Virulence and Clinical Resistance to Antimicrobial Compounds and try to craft a coherent summary. The section, "Physical properties and technological applications", needs to be looked at very closely.....most of it has nothing to do with melanin. --JWSchmidt 17:29, 1 October 2007 (UTC)
Black skin may enhance the body’s natural immune system
[edit]Black skin may enhance the body’s natural immune system, and provide better protection against disease than white skin. Evidence shows that melanization of skin and other tissues form an important component of the innate immune defense system (Mackintosh, 2001; Nosanchuk and Casadevall, 2006). See full article here. --70.68.179.142 (talk) 07:22, 29 May 2008 (UTC)
- AfricaResource is hardly a scholarly research publication. "Evidence" would be you posting links to a few peer-reviewed academic journal articles of original research.Pstanton 23:50, 15 November 2008 (UTC) —Preceding unsigned comment added by Pstanton (talk • contribs)
- This subhead drew my attention, because, to me, it seemed plausible from the git-go. Melanin is part of the body's immune response. It is part of the reason when people are injured, darker scarring, or hyperpigmentation, occurs. Melanin rushes to the site of a wound as part of the body's defense/healing response. Discounting Africa Resource out of hand because it is a black publication and not a scholarly journal doesn't hold up. One might use a similar argument to completely discount/dismiss every single word in this online encyclopedia. If you'd bothered to hunt the (active) link[7] to check out the article, you would see that it is studded with appropriate citations from scholarly research. deeceevoice (talk) 06:59, 12 July 2009 (UTC)
Melanin deniers?
[edit]I've noticed there's this 'Dr Sebi' fellow who is saying Melanin doesn't exist or that there's no proof of it existing, stuff like that. Does anyone know if other people are denying it? Would this be relevant to mention on the article to people know the background of these conflicts, how they began, whether they're ongoing, that sort of thing? An example is this where he really seems determined it doesn't exist... and that melanin's role is served by carbon or something? Why would he conclude this? Tyciol (talk) 09:05, 9 August 2008 (UTC)
- I'd doubt he's actually a doctor, as no one who denies the existence of something so easily confirmed and generally accepted as melanin is ever going to complete an undergraduate pre-med track, much less Medical school and a residency and board examinations. I'd say he can be dismissed as a quack.Pstanton 23:52, 15 November 2008 (UTC) —Preceding unsigned comment added by Pstanton (talk • contribs)
Molecular structure
[edit]Does anyone know of a good picture of the molecular structure of Melanin? It'd be good to have a photo+infobox in this article, most molecular biology articles have a similar setup. I looked for a photo of the melanin structure, but couldn't find one. --Pstanton (talk) 23:48, 9 February 2009 (UTC)
Unclear passages
[edit]"This melanogenesis-based tan takes more time to develop, but it is long lasting." What does "takes more time" refer to? More than what other process? —Preceding unsigned comment added by 130.60.228.187 (talk) 13:47, 13 May 2009 (UTC)
"In the brain, tissues with melanin include the medulla and zona reticularis of the adrenal gland" -- This can't be right. The adrenal gland is definitely NOT found in the brain. — Preceding unsigned comment added by 66.203.207.66 (talk) 19:27, 12 July 2011 (UTC)
Melanin in sunscreens?
[edit]I apologise in advance for any following Naivety; but this idea is the result of me doing my GCSE case study.
For my project I have been researching sunbathing. I found out about Melanin, and bearing in mind it's photoprotectant properties (and conventional sunscreens inability to provide protection against UVA radiation[a cause of melanomas, a particularly fatal variant of skin cancer]). I am wondering why manufacerers don't add it to sunscreens. Is my theory OK but financially non-viable; or does Melanin de-nature or in any other way become dangerous in sunscreens? Sorry for above above stupidity. :-) Stanton13 (talk) 17:34, 8 July 2009 (UTC)
- No naivete. It's already being done. ;) deeceevoice (talk) 06:36, 12 July 2009 (UTC)
More on melanin at Melanin theory
[edit]For more on the properties of melanin, someone might want to visit the section of Melanin theory treating conspiracy theories. I've added information there that should also be included in this article. It has to do with melanin and addiction. Some of you more familiar with the field than I might also want to check what I've written for accuracy/clarity. deeceevoice (talk) 07:04, 12 July 2009 (UTC)
Parkinson's
[edit]This article seems to contain weasel wording on the section for parkinson's. It cites a 1972 article claiming that the higher levels of melanin in blacks gives them a protective factor against parkinson's. This thinking is also used on the "melanin theory" article. More recent research finds things like hispanics to have higher frequencies if parkinson's, rather incosistent considering how they're darker: http://aje.oxfordjournals.org/cgi/content/short/157/11/1015 —Preceding unsigned comment added by 68.62.1.91 (talk) 16:09, 6 July 2010 (UTC)
Human adaptation
[edit]Article says "With humans, exposure to sunlight stimulates the skin to produce vitamin D. Because high levels of cutaneous melanin act as a natural sun screen, dark skin can be a risk factor for vitamin D deficiency in regions of the Earth known as cool temperate zones; i.e. above 36 degrees latitude in the Northern hemisphere and below 36 degrees in the Southern hemisphere" However Pro vitamin d is produced by UVB (280- 315nm) according toSunlight, vitamin D and skin cancer By Jörg Reichrath and very often there is sunlight which does not have sufficient UVB to synthesize provitamin D. Another thing, it's not certain that melanin does filter out the wavelengths which produce vitamin D synthesis The value of melanin as a sunscreen says "The detailed structure of the absorption spectra of epidermal melanin pigmentation in vivo together with the reactivity of melanin precursors and metabolites to ultraviolet A (320-400 nm) and visible (400-700 nm) radiation indicate that epidermal melanin may not be considered simply as passive absorber in the skin that acts as a neutral density filter – i.e. absorbing equally strongly at all wavelengths. {...}by studying the action spectra for the erythema and pigment reactions of skin to ultraviolet radiation for individuals of different levels of pigmentation. Here we find that epidermal melanin is not a neutral density filter providing no or minimal protection for the induction of erythema at 295 and 315 nm and some protection at 305 and 365 nm.". Now the Wikpedia article says "Because high levels of cutaneous melanin act as a natural sun screen, dark skin can be a risk factor for vitamin D deficiency in regions of the Earth known as cool temperate zones" That should be "dark skin may be a risk factor " because the Institute of Medicine of the National Academies' recent report says "some subgroups—particularly those who are older and living in institutions or who have dark skin pigmentation—may be at increased risk for getting too little vitamin D". May suggests there is a possibilty whereas can is stronger and implies it is a fact. There is evidence that melanin is not the cause of low vitamin D levels. Blood vitamin d levels in relation to genetic estimation of African ancestry "African-Americans generally have lower circulating levels of 25 hydroxyvitamin D [25(OH)D] than Whites, attributed to skin pigmentation and dietary habits. Little is known about the genetic determinants of 25(OH)D levels nor whether the degree of African ancestry associates with circulating 25(OH)D. {...} We found novel evidence that the level of African ancestry may play a role in clinical vitamin D status". There is a degree of scientific uncertainty about melanin and vitamin D. Overagainst (talk) 15:24, 16 December 2010 (UTC)
Medical advice
[edit]Article says "health authorities in Canada and the USA have issued recommendations for people with darker complexions (including people of southern European descent) to consume between 1000-2000 IU (International Units) of vitamin D, daily, through Autumn to Spring" Reference please! Overagainst (talk) 17:14, 16 December 2010 (UTC)
Tanning salon given as reference? Additional damage to text?
[edit]Trying to figure out what was being compared in the second sentence below—and why POV seemed to hint at the desirability of a longer-lasting tan, even one occasioned by DNA damage—led me to its footnote, which is a link called "tanning tips" leading to the page of a tanning salon.
- "Production of melanin is stimulated by DNA damage induced by UVB-radiation,[1] and it leads to a delayed development of a tan. This melanogenesis-based tan takes more time to develop [than what?], but it is long lasting.[2]"
Now I wonder whether, in addition to the insertion of a peculiar sentence with advertising as a reference, the first of the sentences has been compromised, in the interest of a false continuity. Best to all, Michael (talk) 08:14, 25 April 2011 (UTC)
Introduction needs complete rewrite
[edit]Melanin pigmentation of hair, skin, and eye is thought to result from two separate but biogenetically interrelated classes of pigments: eumelanins (black-brown, insoluble in dilute alkali) and pheomelanins (yellow to reddish-brown, alkali soluble). Eumelanins are generally considered to be derived from the enzymic oxidation of tyrosine through 3,4-dihydroxyphenylalanine (dopa), whereas pheomelanins arise by a diversion of the eumelanin pathway through the intervention of cysteine or related sulfhydryl compounds. A major intermediate in the biosynthesis of pheomelanins is the dopa metabolite 5-S-cysteinyldopa. (Novel free radicals in synthetic and natural pheomelanins: Distinction between dopa melanins and cysteinyldopa melanins by ESR spectroscopy Sealy RC et al (1982) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC346312/pdf/pnas00448-0150.pdf)
124.187.25.55 (talk) 09:57, 21 August 2011 (UTC)
- Agree, 1982 is an old paper. There is a lot to improve in the article, including scope. Race issues and albinism probably don't need to be badly restated in this biochemical article (only some non-syndromic oca types of albinism are caused by melanin production per se, as some others are related to lysosome related organelles in general - also many people with albinism not so much care about the melanin which other people tend to be focused on, but their fovea and bcva being below 30/100). Nowadays it is believed tyrosine is converted to dopaquinone directly. 10.1074/jbc.272.42.26226 "We conclude that tyrosinase does not possess two separable activities,i.e. tyrosine hydroxylase and DOPA oxidase; the enzyme catalyzes the production of ortho-quinones from both monohydric and dihydric phenols." See also 10.1111/j.1751-1097.2007.00238.x --84.250.122.35 (talk) 21:11, 20 November 2016 (UTC)
Started bio on Peter H Proctor, important melanin researcher
[edit]Started bio on Peter Proctor, in important melanin researcher. Welcome input. Nucleophilic (talk) 17:42, 24 January 2012 (UTC)
Drug Addiction
[edit]Article needs to include a section about the role of melanin with the addiction of cocaine, nicotine, etc. http://www.sciencedaily.com/releases/2009/05/090508134951.htm and http://www.pnas.org/content/106/16/6772 — Preceding unsigned comment added by 67.85.3.79 (talk) 14:43, 27 March 2012 (UTC)
hello??? — Preceding unsigned comment added by 67.85.3.79 (talk) 03:03, 2 December 2012 (UTC)
UV Non-Ionizing Radiation
[edit]I changed a sentence in the human adaptation section to remove mention of ionizing radiation effects of UV rays here:
- "The melanosomes in each recipient cell accumulate atop the cell nucleus, where they protect the nuclear DNA from mutations caused by the ionizing radiation of the sun's ultraviolet rays."
UV radiation is not true ionizing radiation but exhibits some of the same characteristics. I feel the mention of ionizing radiation only confuses the issue here. from the ultraviolet wikipedia page where it notes UV that is involved in malanin production is non-ionizing:
- "UV light is found in sunlight and is emitted by electric arcs and specialized lights such as black lights. It can cause chemical reactions, and causes many substances to glow or fluoresce. Most ultraviolet is classified as non-ionizing radiation. The higher energies of the ultraviolet spectrum from wavelengths about 10 nm to 120 nm ('extreme' ultraviolet) are ionizing, but this type of ultraviolet in sunlight is blocked by normal dioxygen in air, and does not reach the ground. However, the entire spectrum of ultraviolet radiation has some of the biological features of ionizing radiation, in doing far more damage to many molecules in biological systems than is accounted for by simple heating effects (an example is sunburn). These properties derive from the ultraviolet photon's power to alter chemical bonds in molecules, even without having enough energy to ionize atoms."
Silve Slade (talk) 16:11, 31 May 2012 (UTC)
Chemistry of eumelanin
[edit]"The most common biological melanin is eumelanin. This is a brown-black polymer of dihydroxyindole carboxylic acids and their reduced forms."
I am not a chemistry but shouldn't it be oxidised forms. Don't you oxidise a hydroxyl to get a ketone? Mrmessy1 (talk) 22:43, 8 May 2013 (UTC)
Refractile?
[edit]There seems to be contradictory language in the article. The microscopic image at top of page shows dark spots, and describes them as "light refracting." It appears that these bodies are mostly absorbing light, but could also be refracting what is not absorbed. Later in the article, melanin is described as "non-refractile." Could we have an expert weigh in more on optical properties?
Many Different Melanins
[edit]This article should expound on racial differences noting which melanins are found in which races and which ones are not as well as the role of mixed races. — Preceding unsigned comment added by 2602:306:C518:6C40:96E:4871:B481:E70E (talk) 12:26, 18 January 2014 (UTC)
Change statement about neuromelanin that implies Intelligent Design?
[edit]I am an ID advocate, but I've noticed that WP articles do not editorially support ID. So I'm wondering for consistency sake if this statement in the article's intro should be changed: "Neuromelanin is found in the brain, though its function remains obscure." Back when it was hardly questioned that more than 90% of our genome had no function, it would have been inconsistent to say of a non-coding region that "its function remains obscure." But like with "junk DNA", design advocates can predict that neuromelanin has significant function. So it might actually hinder scientific discovery for a popular resource like WP to be silent and to not reference its expected function. So, do we remove the "function" statement, or leave it there? Bob Enyart, Denver KGOV radio host (talk) 13:54, 4 July 2015 (UTC)
- This ten year old paper at PubMed, Neuromelanin in human dopamine neurons: comparison with peripheral melanins and relevance to Parkinson's disease, explores some proposed function. Bob Enyart, Denver KGOV radio host (talk) 14:19, 4 July 2015 (UTC)
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Bacterial Melanins
[edit]Most bacteria can produce a mixed melanin which is very easy to purify.The melanin can be utilized for various applications Kurianoble2016 (talk) 04:34, 14 September 2016 (UTC)
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Melanin semiconductor, why isn't there a section?
[edit]Why isn't there a section on this, in the past there was a section I'm assuming someone deleted. But its in fact a semiconductor and needs to be added. Ankhael (talk) 15:25, 12 February 2019 (UTC)
Melanin Photosynthesizing Capabilities In Humans And Animals
[edit]I have read some interesting articles on melanin is now being looked at to having photosynthesis capabilities, and may change the way we assume that plants where the only living things to use light and convert into metabolic use. They are now looking at the possibility that humans and other animals may have these photosynthesis capabilities to using melanin. The articles are not peer reviewed. The same content has been published numerous times and not once has there been a published experiment. The papers are used to sell fraudulent medicines.
References 1.The role of human photosynthesis in predictive, preventive and personalized medicine https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4125832/
2. Melanin directly converts light for vertebrate metabolic use: heuristic thoughts on birds, Icarus and dark human skin. https://www.ncbi.nlm.nih.gov/m/pubmed/18479839/ Ankhael (talk) 15:47, 12 February 2019 (UTC)
I think should be added to the article and possibly having its own page, do to the massive info i seen oh the subject. Ankhael (talk) 15:49, 12 February 2019 (UTC)
These are articles that are not peer reviewed and are from a fraudulent source. Notice that none of the referenced articles include experiments to verify these claims.
Molecular structure: infobox vs. article?
[edit]There seems to be a contradiction between the article and the infobox concerning the structure of melanin. The article says at the beginning that melanin "is a broad term for a group of natural pigments". Further down various structures are shown:eumelanin, pheomelanin, neuromelanin, etc. which all have different families of structures.
However the infobox says that melanin has a specific structure with formula C18H10N2O4. This is supported by the references to Chem Spider and PubChem (the CAS link doesn't work), so I presume that the information has some validity. However the article does not make clear why the infobox structure has the same name as the whole family of compounds. Is this a structure from which all the others are derived?? Not very obvious as the infobox structure has five fused rings which is not true for the other structures in the article. Is this the majority component of biological melanin?? If so it would be good to add a representative composition with a source. And if these two guesses are wrong, could someone please clarify the relation between the infobox melanin and the whole family of compounds? Dirac66 (talk) 21:08, 4 May 2019 (UTC)
- I put some time into researching this. The structure in the infobox is incorrect, this paper gives details the history of this structure , basically, this was the inferred structure based on the empirical formula and the incorrect assumption that it corresponded to a heterogenous polymer. The infobox needs correcting, I'll give it a go. --Lucaswilkins (talk) 14:23, 13 September 2021 (UTC)
Editing the infobox
[edit]The infobox shows a putative structure of melanin that is always, or very nearly always, incorrect. Others (see above) have noted that this leads to some confusion. The issue is summarised here: "Eumelanin from different sources is heterogeneous in size and in its fine chemical structure. Following the empirical formula (C8H3O2N) suggested by Mason [29], there are still some data on websites giving a defined stoichiometric structure [30] where melanin, ID: 4884931, is defined with the molecular formula C18H10O4N2, an average mass of 318.3 for the minimal unit, and the systematic name 3,8-dimethyl-2,7-dihydrobenzo[1,7]isoindolo[6,5,4- cd]indole-4,5,9,10-tetrone, [30] Figure 2(a). As Mason’s original proposal, these data should be considered as an empirical approximation. The natural occurrence of indole rings condensation assumed at the above tetrone model is very unlikely, although it has been sometimes proposed, as in the eumelanin pigment formed in the insect exocuticle [31]."
So, the main chemical databases also have this issue, so that unless someone really looks into it, they're going to find the wrong structure. I think that best way forward is to just remove the infobox, but I expect someone will just restore it without really looking into it. --Lucaswilkins (talk) 14:43, 13 September 2021 (UTC)
- I have changed the chembox to a material info box. The issue being that melanin isn't really a chemical. The material infobox might not be the best plan, but I couldn't think of a better way. I've moved the chembox alongside a new section that explains the difficulties discussed here, and renamed it to 3,8-dimethyl-2,7-dihydrobenzo[1,7]isoindolo[6,5,4-
cd]indole-4,5,9,10-tetrone. Lucaswilkins (talk) 16:47, 13 September 2021 (UTC)
What is allomelanin and pyomelanin
[edit]What are they the article only says that they are nitrogen free but what are they and what is the effect of them — Preceding unsigned comment added by 64.222.180.90 (talk) 18:16, 9 May 2022 (UTC)
reference 0?
[edit]what’s up with reference 0? Anyone know how to fix? JuanTamad (talk) 09:27, 18 November 2022 (UTC)
Gingers are defective, why not just say so?
[edit]| Pheomelanin, which is produced when melanocytes are malfunctioning due to derivation of the gene to its recessive format,
Perhaps my genetics is rusty, but not only is this sentence only present to insult red-heads, but i have not the faintest clue what derivation of the gene to its recessive format could possibly mean. 68.123.8.175 (talk) 21:01, 7 January 2024 (UTC)
"Frontiers with the unknown"
[edit]The quote in the introductory paragraph is fun, whoever wrote the piece being quoted is clearly enthusiastic about the mysteries of melanin, but is it useful for a lay audience? I feel like it misrepresents the significance of melanin in a larger context. It's not as if biology suffers from a lack of unknowns besides how melanin functions. Mabolle (talk) 10:39, 18 March 2024 (UTC)
- I agree, melanin is mysterious and a fruitful area for new research, no doubt, but so are several other different biomolecules I can name off the top of the top of my head… and “last remaining” frontiers? Aside from the fact that we’re nowhere near reaching the “last” frontiers of biology, when one does think of which mysteries will be the last to be solved one thinks of holy grails like cracking abiogenesis and such. 2804:14C:6590:4E59:7DDD:E23D:214B:BBE0 (talk) 02:30, 23 April 2024 (UTC)
- It is a mere lyric fragment of the Nature magazine article (a quote, to say exactly), which serves as a source here. It means that melanin is not just a pigment, but it bears other functions, that we are getting to know about. They are described in the article. Probably, it should be rephrased. Tosha Langue (talk) 07:15, 23 April 2024 (UTC)
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