Were Earliest Humans All 1 Species? New research on the early hominid remains from Dmanisi have revived the fortunes of paleoanthropology’s lumpers in their age old battle with the splitters!
To learn more about the roots of the human family tree, scientists investigated a completely intact, approximately 1.8-million-year-old skull excavated from the medieval hilltop town of Dmanisi in the Republic of Georgia. Archaeological excavations there about 30 years ago unexpectedly revealed that Dmanisi is one of the oldest-known sites for ancient human species out of Africa and the most complete collection of Homo erectus skulls and jaws found so far.
This new skull, called Skull 5, was discovered alongside the remains of four other skulls of ancient humans, all of them associated with the same location and period of time, which back 1.8 million years ago was a relatively temperate mix of forest and steppe near a river. The fossil is unlike any other Homo remains on record — it combines a long face, massive jaw and large teeth with a small braincase, just about a third the size of that found in modern humans and no larger than those of much more primitive African fossils and even modern gorillas. Scientists hadn’t observed such a combination of features in an early Homo fossil until now.
The level of variation seen in Homo fossils is typically used to define separate species. However, the scientists found the level of diversity now seen between the five sets of fossils at Dmanisi — Skull 5 and the four other specimens — is no greater than any seen between five modern humans or five chimpanzees.