Are your part Neanderthal?
One of the more interesting debates in anthropology is whether or not humans mated with Neanderthals. Recent research into the Neanderthal genome provides some compelling evidence that we did.
Who are Neanderthals? #
Neanderthals were our closest cousins, living in Europe and Asia until about 30,000 years ago, when they went extinct. Neanderthals and humans both evolved from the same shared ancestor, Homo Erectus, a small hominid that migrated out of Africa about 2 million years ago.
Countrary to popular belief, Neanderthals were not stupid cavemen. They actually had larger brains than humans, though of a slightly different shape.
Neanderthals had tools, ceremonies and language. If you were sitting next to one in a subway, you’d probably just think they were a funny looking human.
So… did we mate? #
Most likely, yes. Despite the debate, many anthropologist believe that humans and neanderthals mated and maybe even had children.
The bigger question is: Did they pass on any of their genes?
Hybrid species are quite common in the wild. But, they’re often sterile. Ligers (lion-tiger hybrids) and mules and hinnies (donkey-horse hybrids), for example, cannot reproduce.
Many anthropologists speculate that if neanderthals and humans mated, they would have had sterile offspring and therefore no neanderthal genes would have spread into the human gene pool.
Recent research into the Neanderthal genome may prove otherwise.
Comparing Genomes #
Peter Parham, a professor of microbiology and immunology at Stanford, compared the human genome to the Neanderthal genome.
HLAs comprise a group of about 200 genes that are a vital part of our immune system. Some of these genes, known as alleles, are variable due to natural mutations in our chromosomes that occur as we continue to evolve in ways that hopefully help us fight off new diseases.
Parham found after studying HLAs in modern European and African people that early European humans developed alleles in their genes that were identical to the ones found in Neanderthals, which quite naturally leads to the conclusion that they got there via breeding. One allele in particular, HLA-C*0702, found in the Neanderthal, is quite common in modern European and Asian populations, but is absent in modern Africans.
That last sentence is incredibly important. Since humans and Neanderthals both evolved from Homo Erectus, any shared genes could easily be attributed to that common ancestry.
The most commonly accepted theory of human evolution is that we came into existence about 250,000 years ago in Africa, and then around 100,000 years ago, we started migrating out (just like Homo Erectus did a few million years earlier).
Since Neanderthals were only located in Europe and Asia, the absence of these common genes in African populations indicates that they were picked up through mating and not shared ancestry.
Conclusive? Hardly. But it’s compelling nonetheless.
More Reading #
If you find topics like this as fascinating as I do, here’s some additional reading…
- Physorg.com – Breeding with Neanderthals appears to have helped early humans fight disease
- National Geographic: Last of the Neanderthals
- Discovery: The Real Eve
- Origins of Modern Humans: Multiregional or Out-of-Africa
- Wikipedia: Neanderthal, Homo Erectus, and Recent African Origin
Image by Andrea Piscopo