Timeline for Would a black population whiten over generations because of living underground?
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
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| Dec 22, 2016 at 8:33 | vote | accept | CommunityBot | ||
| Jun 1, 2016 at 13:40 | comment | added | Jason K | If there was absolutely ZERO selection pressure on melanin production then I think the population would eventually come to have a wide range of colors, as the genes for MAXIMUM melanin production would suffer mutations that cause less melanin production in offspring (since the normal function is max melanin, the only possibility is less production), and with zero selection pressure (social, environmental, etc) those genes would be distributed around and you would see some dark individuals and some lighter ones. | |
| May 31, 2016 at 8:28 | comment | added | Vakus Drake | Well obviously vestigial traits that serve no purpose exist (though many like the appendix have been repurposed for a niche function [it serves some function as a bacterial reservoir]) However a trait that serves literally no purpose will always use up some marginal amount of energy to grow in the first place thus making it have a slight negative value. Over large enough timescales no trait has zero affect on fitness. | |
| May 31, 2016 at 7:36 | comment | added | Nathan Griffiths | "Any trait that isn't actively serving a purpose will eventually be lost" - sorry but that is not how evolution works. Traits that provide an advantage will win out over ones that don't, but if there is no disadvantage in having a particular trait there is no reason it would just disappear. | |
| May 30, 2016 at 14:51 | comment | added | Vakus Drake | Any trait that isn't actively serving a purpose will eventually be lost, especially one that can change as quickly as melanin level. Some amount of energy has to be spent producing melanin so there will be some slight advantage to producing less of it if it isn't serving any function. | |
| May 30, 2016 at 5:00 | comment | added | Nathan Griffiths | As I said, if there was some social or other advantage to a particular skin colour then yes, it would eventually lead to a change in the dominant genes. In the scenario described in the question there is no obvious disadvantage to having a particular skin colour, we would need to know more about this environment, level of technology, possible predators, social/moral behaviours etc. before being able to say whether any skin colour was likely to have an advantage. | |
| May 30, 2016 at 3:23 | comment | added | Vakus Drake | Even with the weak being helped by the strong (that's not as rare as you might think among social animals), that doesn't change the fact they will have some minor disadvantage, if a trait provides even a miniscule advantage it will eventually dominate the gene pool. | |
| May 29, 2016 at 3:44 | history | answered | Nathan Griffiths | CC BY-SA 3.0 |