I remember hearing exactly this sort of thing in my anthropology/archaeology courses while I trudged through university attaining my first degree. Maybe you’ve also taken similar courses in the past, and have heard the same kind of thing. Well, a recent discovery in Dmanisi serves to lend much credence to this theory after all.
The skull, named ‘Skull 5’, appears to have traits belonging to African hominids dating from at least two million years ago, and also traits belonging to Eurasian hominids dating to around 1.5 million years ago. The skull was found in a pit with four other humanoid fossils, each of them slightly different from the others. And with several animals, all dating to around the same time.
The hybrid appearance of Skull 5 has made the researchers studying it begin to turn towards the theory of human evolution that basically says we’re all still Homo erecti – just different ‘breeds’, so-to-speak, of the original erectus line. In other words, our entire hominid line hasn’t speciated (formed new species) at all in over two million years.
For two million years our line has been diversifying, especially once we started migrating out of Africa. I imagine the main thing that would keep us from speciating during this time would be a healthy amount of interbreeding continuously occurring across vast expanses of our population. Of course, this tradition continues, definitely moreso, to this day.
So, instead of wracking one’s head in futility trying to construct a ‘normal’ phylogeny for the hominid line, as is usually possible for most other animals, one should construct more of a bubble-shaped phylogenetic tree and simply label the various ‘buddings’ as different kinds of a one particular species of hominid – whatever one we wish to go with.
That means we must start to think like this
As opposed to this:
Ann Gibbons (2013). Stunning Skull Gives a Fresh Portrait of Early Humans Science DOI: 10.1126/science.342.6156.297