When did Fins become predominantly blonde?

Question

What time could it have taken an isolated blackhaired tribe to become predominantly blonde haired?

What could have been the factors in the genetical selection which gave advantage to blonde (blue eyes) individuals over black haired individuals? Energy efficiency?

Why aren't there isolated blonde hair groups or brown hair groups in Asia? Why don't Asians who live on the same hemisphere as brown hair-green eyes kaukasians, have green eyes?

Answer 1

fair skin people are able to make more vitamin d from sun light than darker pigmented people. since vitamin d is necessary for health & reproduction & people that live in cold climates cover most of their skin with clothing it follows that people that are bald or have fair hair so more sun light reaches their face & scalp will have a survival advantage over other people in the same climate. the people that currently live in the north american arctic have traditionally eaten a lot of animal liver & get their vitimins 2nd hand that way since they get hardly any sun at all that far north. the people of the caucasus region were origionally indo/european nomads that settled in that area & in fact did spread into parts of Asia on horse back.

Answer 2

Well, it's cold in Finland, so the people don't get tans.  And having dark hair and eyes is your body's way of protecting you from the sun.  But again, there's little sun in Finland, so the people don't need to protect their hair from scorching or their eyes from blinding.

Answer 3

Well, you already have the predarwinian answer that "spdesai7" has given you. Most people stick to this simple answer. And it is true to some extent. But after Darwin you must consider that not all physical traits have a "reason". Yes it is true natural selection favors some characteristics and disfavors others, but it is not true that all characteristics of a given species in a given moment of it's evolution are "needed" for that species to survive. Otherwise nature would have nothing to "select" from. On the contrary, variation is needed.

So the predarwinian idea that the environment determines your skin color cannot explain why in the same environment you can find other skin colors, as was questioned about Saamis (Laplanders) in the same region you mention.

Answer 4

the Vikings hung around there

and they were very horny

just look at their helmets

they left blondness all over the place

In Marocco,Ireland Wales Portugal and Finland was just around the corner.

these geesare said to come originally from Mars

from the Nordics

who abandoned the place before the Cosmic collision

and this race was also in Babylon.

blond blue or green eyed .

I am one of those ,but my hair got darker over time

from hanging out with Africans and Mexicans i guess

realy true

Answer 5

The time it takes depends on how large the group is...  A very small group might begin to show the mutation in just a couple of generations....where as a large group... or a group that interbreeds with other groups would take much longer...

There are many theories as to why light skin and light colored hair became so wide-spread amongst northern-europeans... One theory is that in the cold, it became harder to determine how old a person was (because they were wearing so much clothes to keep warm... and people whose hair was lighter gave the appearance of being younger(since most people have lighter colored hair when they are young).  Another theory is that a sick person who is light skinned can easily be identified (their skin looks pale or yellow or green)... where as a dark-skinned sick person cannot be identified just by looking at their skin.  And people would choose to mate with people who are more easily identifiable....

The reason that asians might not have had light colored eyes, hair, or skin... could be that (1) that mutation never occured in their ethnic group.  If the mutation never occurs...it can never be passed down.  OR (2) if the mutation did occur, perhaps their population was too large.  And since light-colored skin, hair, and eyes are rececive they might have been kept down so long that they eventually just disappeared from their genetics...