Modern Humans Bred With Evolutionary Predecessors In Africa
NewYorkCountryLawyer writes "Based on a new analysis of old skulls, it now appears that modern humans may have interbred with some earlier hominid species, suggesting that human evolution took a more complex path than previously thought. The study opines that modern humans lived side by side with the older species. Paleontologists disagree over the meaning of the findings, or whether they have any substantial significance at all."
The definition of species isn't very good. It's a convenient abstraction, and works in a lot of cases, but it doesn't entirely reflect reality. There are, for example, ring species that break it, and lots of fertile hybrids between species, and even hybrids between genera, especially in plants. Often, hybrids are not fertile, but sometimes they are. But it's important to remember that fertility isn't the only barrier to inter-species mating; behavioral, temporal and geographic barriers also play a very important part.