How Neanderthals stopped humans being wiped out by flu

Modern humans may have been wiped out by flu if they had not mated with Neanderthals, a new study suggests. Scientists at Stanford University have discovered that ancient trysts led to the swapping of important DNA which protected humans from diseases after they left Africa.

Neanderthals became extinct around 40,000 years ago, but most modern Europeans still carry about two percent of their DNA in their genomes. The researchers found that the 152 genes we inherited from Neanderthals interact with modern day influenza A and hepatitis C, and helped our ancestors fend off the diseases when they encountered them.

"Neanderthal genes likely gave us some protection against viruses that our ancestors encountered when they left Africa." When first contact occurred between the two species, Neanderthals had been living outside of Africa for hundreds of thousands of years, giving their immune systems ample time to evolve defenses against infectious viruses in Europe.

For the study scientists compiled a list of more than 4,500 genes in modern humans that are known to interact in some way with viruses. They then checked his list against a database of sequenced Neanderthal DNA and identified 152 fragments of those genes from modern humans that were also present in Neanderthals.

https://www.telegraph.co.uk/science/2018/10/04/neanderthals-stopped-humans-wiped-flu/