Scientists have sequenced the genomes of five new Neanderthal tribes. This gives scientists an idea about how Neanderthals lived. This also tells scientists when humans and Neanderthals began to interbreed.
The genome can also show how much of human DNA came from Neanderthals.
Five Different Tribes
Researchers from the Max Planck Institute For Evolutionary Anthropology released a paper in Nature on the genome sequencing. They extracted small amounts of bone or tooth powder. To avoid contamination, they used a chemical process to remove modern genetic material.
New Neanderthal DNA came from Mezmaiskaya Cave in Russia. Scientists were able to obtain genetic material from two different Neanderthals who lived in the cave 20,000 years apart. Other Neanderthal genomes that were sequenced came from Belgium, France, and Croatia.
After sequencing the DNA, they found that one of the samples from Vindija Cave in Croatia came from the same individual that had been previously sequenced. Both of the individuals found in Mezmaiskaya Cave were less closely related than previously thought. The first individual lived in the cave 70,000 years ago.
The second individual was found to be more closely related to the Neanderthals from Croatia, Belgium, and France rather than the first Mezmaiskaya individual. This would suggest that the later population may have replaced the first, showing that the first population may have been wiped out.
Researchers did note that periods of extreme cold may have caused the extinction of Neanderthal populations in northern Europe. They also suggested that those populations further down south in Europe may be descendants from Neanderthals that came from northern Europe.
Humans Mixing With Neanderthals
An interesting point in the research suggested that none of their genetic material was present in humans. All the interbreeding that caused humans to end up with Neanderthal DNA occurred between 70,000 to 150,000 years ago, when these Neanderthals were alive.
These Neanderthals did live around the same time as early humans but didn't have any human DNA. This could also show that while Neanderthal DNA may have found its way into humans, there wasn't a DNA exchange in the other direction.
These findings don't explain whether the Neanderthal DNA in humans came from male or female Neanderthals. Researchers also compared the new genomes with those of previously sequenced Neanderthals, Denisovans, and ancient human samples.
Earlier in March, scientists were able to compare Denisovan DNA to other human populations and found that there were two separate Denisovans populations in different parts of Asia. Both of the populations contributed genetic material still found in human DNA.