Thursday, April 14, 2016

Humans Gave Neanderthals Herpes

Among other tropical diseases, humans brought herpes (herpes simplex 2 virus) to Neanderthals living in Eurasia when they migrated northward from Africa.  Geneticists at Cambridge University speculate that the answer to the planet's oldest 'who dunit'--what killed the Neanderthals--may lie in the spread of diseases for which our hominid cousins had no immunity.  Heliobacter pylori, which causes stomach ulcers, is another human germ brought to Eurasia by humans.  The bacteria infected humans in Africa 116,000 to 88,000 years ago and arrived in Europe 52,000 years ago. Genetic evidence shows the two species co-existed and interbred for thousands of years before Neanderthals eventually died out.  About 2-5% of the modern European genome consists of Neanderthal DNA.

There is growing scientific consensus that Homo neanderthalensis was out-competed by modern humans and the disease theory fits that scenario.  Weakened by disease, individual bands of Neanderthals whose gene pool was already shrinking due to geographic isolation could not have competed successfully with their more immune neighbors despite growing evidence they were as intelligent as the recent arrivals from Africa. Stone tools indicating an adept user have been found associated with Neanderthal remains as have bone tools.  A building 26 feet wide created about 44,000 years ago from mammoth bones has been unearthed by researchers in France.  They may have adorned themselves with jewelry made from animal parts and engaged in art.  More genetic evidence indicates Neanderthals possessed the genetic code that allows humans to talk even though advanced mammals communicate effectively without talking.