A recently discovered 1.8 million year old skull suggests that the multiple human species theorized by paleontologists were actually just one.

The uncertainty of science: A recently discovered 1.8 million year old skull suggests that the multiple human species theorized by paleontologists were actually just one. More details here.

It is one of five early human skulls — four of which have jaws — found so far at the site, about 100 kilometers (62 miles) from the capital Tbilisi, along with stone tools that hint at butchery and the bones of big, saber-toothed cats. Lead researcher David Lordkipanidze, director of the Georgian National Museum, described the group as “the richest and most complete collection of indisputable early Homo remains from any one site.”

The skulls vary so much in appearance that under other circumstances, they might have been considered different species, said co-author Christoph Zollikofer of the University of Zurich. “Yet we know that these individuals came from the same location and the same geological time, so they could, in principle, represent a single population of a single species,” he said. The researchers compared the variation in characteristics of the skulls and found that while their jaw, brow and skull shapes were distinct, their traits were all within the range of what could be expected among members of the same species.

I have always thought that paleontologists were too quick to name each new major find as a new species. Among all species there is always a wide variety of features. One person is tall. Another has a big forehead or head. This discovery reinforces this idea. The five skulls were all found in the same place, from the same group. Yet they were very different from each other.