Homo sapiens are so heterosexual, they get all the ladies, even those sexy, sexy caveladies.
“Y chromosome sequences now provide new evidence that Neandertals and early modern humans met and exchanged genes before the major out of Africa migration—potentially as early as 370,000 years ago and certainly more than 100,000 years ago. This implies that some population closely related to early modern humans must already have been in Eurasia at that time. Surprisingly, this interbreeding resulted in the replacement of the original Neandertal Y chromosomes with those of early modern humans, a pattern similar to what has been seen for Neandertal mitochondrial DNA in an earlier study.
“At first, the complete replacement of both Y chromosomes and mtDNA of early Neandertals was puzzling, as such replacement events are quite unlikely to occur by chance alone. However, the researchers used computer simulations to show that the known small size of Neandertal populations may have led to an accumulation of deleterious mutations in their Y chromosomes which would reduce their evolutionary fitness. This is quite similar to situations where extremely small population sizes and inbreeding can sometimes increase the incidence of some diseases. ‘We speculate that given the important role of the Y chromosome in reproduction and fertility, the lower evolutionary fitness of Neandertal Y chromosomes might have caused natural selection to favor the Y chromosomes from early modern humans, eventually leading to their replacement,’ says Martin Petr.”
Clearly most our ancestors had a hankering for neanderthal babes.
