re melanin production in non caucaision, how many generations will it take for the body to produce less ?

Question

I'm wondering melanin production is linked to climate - for familes that have lived in the uk for several generations how many more will it be for the part of the body that controls melanin start naturally to produce less as a result of environmental conditions and lightening the skin tone to deal with new climatic conditions, conversly to this how many generations did it take the average caucasion in say australia to increase melanin production to deal qith the hotter climate ooh this one might be easier to trace 9 im interested in the speed of human evolution to climate,

no this isnt a micheal jackson type question it is specific to how many generations does it take melanin production levels to alter in the human species due to climate change

another way of putting it is how quickly does the human species adapt to altered climates

screwy as it sounds the most likely short term effect of global warming is to throw us into an ice age, thats the cyclic bit of global warming and yes this is a "natural" occurrance that we are speeding up

Answer 1

In the recent coverage of the couple that had one black, one white baby, it is noted that there are about seven genes that control skin colour. The number of generations will be determined by a number of factors - if there is already variation to work with, what the exact selection pressure is, the mutation rate, and whether you are just looking for the initial mutations in these genes (that will later be selected), or the number of generations it will take for the "final" change to be widespread in the population, and if so, how much.

Answer 2

This question is really interesting ... I don't know the proper answer, but my friend is from Sri Lanka. She has lived in Japan for 20 years now, and has become much lighter. Although Japan's summers are very hot, she hates them because they are so humid, so she stays indoors a lot. She is much less dark than when I originally met her. But her daughter, who is half-Japanese is so lucky; in summer, she tans very deeply and in winter it fades; she is like the other Japanese kids who develop tans within minutes of exposure to the sun.
I, on the other hand, love a tanned skin and can't stand to look so pale, and I always got a great tan every summer here, but in the past few years, I find it harder and harder to get a tan! I sunbathe (sensibly) I walk around in tank top and shorts, but I no longer tan! When I do, it takes a long time!
Therefore, I think melanin production is related to aging, more than to evolution.
I am also interested in the "speed of Human evolution" in regards to the climate; and have noticed that the first few years of your life determine the climate you are most comfortable with. Many Japanese parents will not use the air conditioner at home when a new baby is born; they want to let the baby get aclimatized to its natural environment. This makes sense.
I feel my best when I return to England; that climate, although it is often complained about, makes me feel so good! But I am also getting used to the Japanese climate too (took me 20 years). It still bothers me, but not as much as before.
Well, my Sri Lankan friend has avoided the sun and as a result has a rather bleached-out look about her; she has lost that healthy glow which comes from the natural vitamin D ...
I think one thing is sure; it is easier for a naturally dark-skinned person to get even darker if they live in a fiercely hot country and expose themselves. On the other hand, it isn't that easy to get lighter, although it can be achieved in your own lifetime.

Answer 3

i don't know the answer, but here are things to ponder.
melanin has survival value, the greater the value the faster nature sems to use it, thus, i guess lightening would procede slower than darkening.
marriage to a lighter person will effect this, as aperson can only be as dark as the darkest parent, so recessive genes are an issue.
we are entering a period of global warming, which i believe is in part,a normal cycle increased with grenhouse gasses.
i believe it is reasonable to assume that increased temps would slow slowing.
lastly we have ozone depletion. less ozone, more need for melanin, so any conclusion you reach must factor several ideas, including some that i ma have overlooked.
additionally, it could be that one/some of my factors are irrelevant to ms nature.

Answer 4

I'm afraid you are asking a question that can only be guessed at, because we have not known this info long enough. So, as many generation as have passed between the Roman empire and now would not be enough. That's about all I can say with any sureness.

Answer 5

One good method, is to check the price of Oreo cookies per pound per pound and compare per pound per euro. The American dollar will reflect those changes...so vital to the economy, and thus altering the effect of global warming...please cross index methane production and combustibility studies during the "Thunderdome" filming. That was done in Australia.

Have a nice day.
Get a job,
Mister

Answer 6

. . . is this a Michael Jackson-type question? . . .