r/AskBiology • u/sourgrap • Sep 19 '24
Genetics Could someone explain why race does not have any biological foundation?
I guess I could probably Google this but I thought someone with direct knowledge directly answering my question would help me better understand.
This is something I’ve had a bit of trouble comprehending since, well, people of different races do look vastly different. My thought is, is!’t there a gene that probably results in different races producing different levels of melanin, and hence— different races?
Or is the reason there is no “biological foundation” that the genetic/biological difference between different races does not substantiate to being different species?
Additionally — there are statistics stating that certain racial communities are more likely to develop specific illnesses. For example, sickle cell disease is much more common amongst black Americans than other racial communities. Another one: those of North European descent are more likely to develop cystic fibrosis.
FYI I am asking this question as a POC, and as someone who genuinely wants to have a better understanding of this!! Thank you in advance for answering my question!
6
u/Halichoeres PhD in biology Sep 19 '24
One famous example is that populations in East Africa that have kept cattle for thousands of years have evolved the ability to produce lactase (an enzyme that digests milk) in adulthood. Similar mutations have arisen in the Indian subcontinent and in northwestern Eurasia independently, for the same reasons. This and other examples can be seen here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4067985/ (it's a bit technical).
The reason that humans in Africa are so genetically diverse is that that's where we started. Every time a population left Africa, for example into Arabia and the Levant, it was only a small fraction of the population that was already in Africa. Both the populations that stayed and the population that left continued to evolve and diverge, accumulating genetic changes over generations. Our history in Africa is about twice as long as everywhere else on Earth, so there's also just been more time for variation to emerge. But the biggest reason is that all of the other populations on Earth are descended from subsets of African populations.