According to the team, the forced interbreeding
triggered shorter life spans and a spate of health problems which eventually led to their extinction.
Those who suspect that Neandertals and other Stone Age hominid species had a big evolutionary impact say that ancient DNA represents the first step to understanding the power of interbreeding
in human evolution.
The bits of Neandertal and Denisovan DNA carried by Melanesians encompass genes involved in metabolism and immunity, indicating that interbreeding
influenced the evolutionary success of ancient humans, Vernot's group reports.
Moreover, in a surprising turn of events, DNA evidence from these ancient remains revealed a link into interbreeding
among early humans from the Stone Age and Neanderthals.
That suggests the signal came directly from ancient mixing with Neanderthals, and not recent interbreeding
with other modern humans whose ancestors might have interbred with Neanderthals.
The Barents Sea is itself under threat from climate change, petroleum exploration, heavy shipping traffic and lightly regulated cod farming (which threatens wild populations through interbreeding
with escaped farm fish).
He and Fiksdal said that within one to five years, most of the bees in the county will have been Africanized through natural interbreeding
Evidence of that Stone Age interbreeding
was uncovered when researchers found traces of Neandertal DNA slipped into the pages of the human genetic instruction book.
The team, with researchers from the Pontifical Catholic University in Brazil and Universidade Federal do Rio Grande do Sul, said there is no evidence of interbreeding
between the two types of tigrina.
If that interbreeding
did take place, it must have been here.
between Homo sapiens and Neandertals probably occurred during that time (SN: 11/29/14, p.
Researchers said that much more interbreeding
went on between different species of humans than had been believed.
It appears some level of interbreeding
may have occurred in many parts of the world at different times in human evolution," said University of Arizona geneticist Michael Hammer, who conducted the study with a team of evolutionary biologists, geneticists and mathematicians.
An analysis of DNA from a roughly 36,000-year-old modern human fossil found in Russia dates human-Neandertal interbreeding
to about 54,000 years ago, researchers report November 6 in Science.
Research by immunologist Peter Parham suggests that interbreeding
with Neanderthals gave our ancestors a ready-made cocktail of DNA invaluable in fighting diseases common in northern climates.