Hi there,

I have taught biology at gcse level but I have this to ask, as I have not a good awnswer.

So why  for example Chinese people look specifically the way they do. Or say south Americans, or people from Senegal

Is it to do with selective breading so Chinese people choose mates that look more Chinese.

is it almost like a different breed  ( am I using the wrong term?)

I just do not have a satisfactory answer to this.

I would thank any qualified biologist to   posit a reasonable  hypothesis

Genetically there is no evidence for human races. Thousands of people from all over the world have had their genomes sequenced and we are almost identical at the protein level. The differences in facial and body features we see are caused by subtle differences in gene expression between populations, caused by minor differences (SNPs) in the promoters, regulatory and coding regions of genes. These differences have been selected for over thousands of years to allow adaptation to local differing conditions.

Most geneticists and anthropologists view the concept of race as outmoded and a sociological construct. It does not provide meaningful, useful or verifiable differences between humans.

with the advent of travel and mixing of peoples from differing ethnic backgrounds and countries then clearly the above differences reduce and can disappear in time as the various genetic alleles get mixed and reshuffled between generations.

that said the majority of people in say Africa or china will mate with other individuals locally , hence maintaining the visible differences.

This is all about population genetics - nothing more!

David, I can never get this straight in my head:

"Genetically there is no evidence for human races."

But then:

"The differences in facial and body features we see are caused by subtle differences in gene expression between populations, caused by minor differences (SNPs) in the promoters, regulatory and coding regions of genes. These differences have been selected for over thousands of years to allow adaptation to local differing conditions."

That sounds like you're saying there is a genetic cause for the differences we see between different populations. And indeed I can hardly see how it could be otherwise. What is the story here?

it's really semantics Mike!

As you correctly say almost all differences between individuals (human or otherwise) will be down to subtle changes in the expression (levels and timings) of hundreds of different genes.

Separately there is the issue relating to race ie whether human sub-populations (however they are defined eg based on colour of skin, geographical origins etc) are somehow different from each other and have identifiable and measurable characteristics. For the most part the answer is no, hence my comment that there is no evidence for major genetics differences between these sub-populations (aka races) as opposed to differences between individuals.

Hope that's clearer!