The origin of racens of man?

Question

Could you tell me certain geographical aspects and genetic aspects that caused different races to get certain physical features?

Answer 1

Race is kind of an arbitrary description of different human groups, but that doen't mean it is meaningless, or that it doesn't describe groups that have real genetic differences in their 'average'.

Sub Saharan Africans are roughly divisible into three groups, Bantu, who are seen all over Africa but originate in the Congo, and are the physical type that ended up in America as slaves. Then there are Capoid/Khoisanoid people , that live in Southern and Central Africa. They are a mid golden brown colour, and many are still hunter gatherers, and they've been displaced by the Bantu farmers over the past three thousand years. One particular group the Khoisan, have a VERY Chinese look to them, and are genetically the most diverse people, and are thought to look most like the'Out of Africa' people.

The Third group are 'Nilotic', or people along the course of the Nile, from the Masai in Kenya, up to the Nubians in Egypt. They are long and slender, and they skull shape is virtually indistinguishable from a Northern European, making it a reasonable bet that they are they African group the went North into Europe, and into West Asia.

The first known migration wave of humans is sometimes called the 'beach buggy', as it followed the Indian and South Asian coast down to Australia, being mostly mitochondrial DNA type M, although there may have been a prior wave that got wiped out. Look up 'Mungo Man' if that interests you. These people become the Negritos of the Andaman and Nicobar islands, the Tribes of New Guineau, and Aborigines.

A seperate wave of expansion moved inland and across the Asian continent. These became the Mongoloid people (Chinese, Korean etc) Towards the South of Asia these people mix with the 'beach buggy' people, in places like Malaysia, and they moved up into Northern East Asia, and into the Americas.

However, the Asians weren't the first people to make into the New World. They found Australoid (Aborigine like) and Ainu remains that predate that immigration wave, The East coast Native Americans also have a substantial amount of European DNA in them from an ice age settlement, that probably fallowed the ice around from Iberia (Solutrean people). The modern native American is a real mix.

European ancestry is a bit shady. There was probably a founding event someshere near the Caucasus mountains, and one branch (Berber, traceable by MtDNA type X) went along the North Coast of Africa, then up into Iberia, and some ended up in Finland. Another branch ended up tavelling West, and then East again, the Celts. They made it as far as the Uighar province in China, and the odd red head or blue eyed person can still be seen there.

Some of these Causcasians moved into Northern India, the Aryans. There was some population movement  from the horn of Africa (Nilotic) and these became the southern Indians, and they still look really black (Tamil, Sinhelese).

The Asians pobably retained the Epicanthic eye fold (slanted eyes) because they travelled through a very dusty desert cenntral area, and their eye shape makes the eyelashes look down, and that filters out dust well. A lot of racial features like skull shape are just down to founder effects. Say, more people of the colonising group had straight hair, and this becomes the norm through random chance.

Africans are black to protect from high UV levels. Europeans and Northern Asians are light skinned so they can synthesise vitamin D. Also, lighter European eyes see better in red light, like you'd get from firelight, handy for long winter evenings in the cave. The massive variety of Caucasian hair and eye colours is something of a mystery though, which is why a lot of people think that there may be a little Neanderthal blood in Caucasians.

Answer 2

Biologically speaking, there is no support for the categorization of humans into discrete "races". There is more individual variation within a race than there is between races.

Furthermore, there are many hypotheses surrounding physical adaptations - and they are often contradictory. I suggest you take a look at a textbook on Human Variation before you listen to someone on this Answer page.

Answer 3

Would you like the short version or the long one?

Answer 4

Africans, our ancestors, have dark skin and thick dark bushy hair to protect them from the sun.  Other people in similar climates have retained or reevolved some of these characteristics, such as the aborigines of Australia.  The flat noses of both of these peoples are designed for conserving the moisture n the breath.  People in more northern climates have evolved fair skin and hair to increase the absorption of sunlight, which is essential for health, and have longer noses to improve respiration.  People living high in the Andes or Himalayas have much greater lung capacity to compensate for the thin air.  Many adaptations are not visible, such as resistance to certain diseases.

Answer 5

There are no race's. There is only the one race, and the things that separate us are, : Which part of the earth we belong and, : just maybe,: who's family we stem from after the great flood  bottleneck. We could descend from Ham, or Shem, or Japheth, or even Noah himself. I don't think that necessarily means we have to believe in the bible, it just means there were at least four surviving families of the flood.