Why do Africans have large noses and lips?

[Luis]

I was wondering about this question !

I'm studying an Introduction to Human Biology and Nature, and this question pops out from our teacher.

So, do you agree on what i found?

First off, it's a generalization. Not all Africans have large noses and lips. Characteristic facial feature vary from region to region in Africa. In West and South and some parts of Central Africa, those characteristics you stated are what the majority of the Africans look like. But most East Africans, North Africans, and some Central Africans have thin noses, normal - thin lips and usually have curly hair and can have straight/wavy hair. It's not because of mixing with non-Africans, it's because Africans are a diverse people. In fact, Africans are the most diverse ethnic group, according to researchers and scientists.

In fact, many Africans, especially East Africans, tend to marry and have children with people within their country, so that their genes are concentrated. This is proved through genetics tests. The oldest fossils in the world are found in East Africa, mainly Ethiopia, which suggests that the human race began there. According to many evolution theories, as the human community grew, some migrated to other regions in Africa, to Asia and to Europe. The physical characteristics of these races are a result of mutations and climate adaption after migration. An example is white skin which was a mutation that aided the humans living in colder regions, so that their skin could absorb more vitamin D into their bodies from the sun.
As to the large noses and lips of some Africans, I'm not really sure what purpose they served as East Africans living in the same climate do not typically have these features. But there is differences in every group. It's more due to genes being kept within a gene pool (or community) because there are no new dominant genes to override these genes. Also, no one died from having these characteristics as they did not hinder their survival.

[kolean]

Maybe not necessarily big noses, but big nostrils. Bigger nostrils to breath more air in. You would need to breath more air if it contained less oxygen as it might have way back at the beginning of the neanderthal man. And like you stated, perhaps this dominant gene stayed within the gene pool for many generations. And the bigger the nose, the better the procreation partner to have in this culture, keeping the gene pool very dominant.
Lips are interesting to theorize why an extra thickness of muscle would be needed to be a dominant trait of this sequestered gene pool. Somehow getting the food into the mouth would be helpful as the lips can draw it in, and then shut the mouth to keep the food from falling out as it is eaten. Several different cultures even have plates that they put in their mouths to stretch out the lips. Perhaps this is a ritual from way back then.
Just speculating here.

[versus]

I woud say that nostrils of Africans aren't big. They are normal. because they don't need to warm up the air they breathe. And the size of the nostrils in colder places (in the north) got smaller to ensure air wormup before delivering to the lungs.

Lips may have something related to nostrils.
But also its possible that lips are usefull for eating. coz in animlas well developed lips are common in plant eating animals. And in the north people were eating a lot of meat durin previos 10.000 years.

[Jasper903]

I agree with versus. I think it may be temperature/climate based. Colder climates could possibly result in narrower facial features.

http://books.google.com/books?id=Q5fNAAAAMAAJ&lpg=PA185&ots=nXzNvzjXT5&dq=bigger%20nostrils%20result%20of%20climate&pg=PA185

[dawntomorn]

They also actually have the right complexion to protect them from skin cancer. With their noses and lips, it is genetics and may be affected by their adaption of their environment.

[NurseBella]

I wonder then, why do Italians have big noses? Or even, Why do JEws and Aficans share some feature traits?