A well-preserved complete skull from Dmanisi, Georgia, has ignited a firestorm, threatening to declassify various claimed species of Homo into one, Homo erectus.
The Dmanisi sample, which now comprises five crania, provides direct evidence for wide morphological variation within and among early Homo paleodemes. This implies the existence of a single evolving lineage of early Homo, with phylogeographic continuity across continents.
With a new well-preserved, complete Dmanisi fossil, researchers at the cave in Georgia (near the Black Sea) have found five crania with more morphological variation between them than between the various proposed species of Homo (Homo rudolfensis, Homo habilis, etc.). This implies that all these assumed different species should be lumped into Homo erectus. The BBC News calls this a “blow to the multiple species idea.” All these types were just variations on the same kind, as shown in comparisons of the skulls side by side.
It should have been obvious. Living humans exhibit a huge variation in morphology: height, robustness, facial features, limb length – yet they are all one species, Homo sapiens. Perhaps fossil hunters have been a little too eager to split lineages in order to claim fame as discoverers of something new.
Evolutionists date the Dmanisi skulls at 1.8 million years, but other evolutionists claim members of the genus Homo existed in Africa long before that – 2.4 million years. Yet the differences between these skulls are minor, considering the half million years supposedly separating them.
The news articles, like National Geographic, are still fond of calling the specimens “primitive” (they would have to be, to be claimed ancestors of us), but it is widely believed that Homo erectus (now encompassing three members of Homo) used fire, cooked food, and made tools (but somehow never dreamt of planting a farm or riding a horse). Some even think they built floating craft to cross oceans (2/18/10)—a finding so startling it was compared to finding an iPod in King Tut’s Tomb. This is but one example of unexpected modern behavior among “primitive” members of our genus Homo. Ann Gibbons posted a reconstruction in Science of the individual making it look as primitive and hairy as possible, but actually, he looks kind of macho. Earnest A. Hooton cautioned in 1946, “Put not your faith in reconstructions.” Given the variation found among the skulls, how is one to know this one was typical?
The brain case of the new skull has been measured at 546 cc, about a third of many modern human skulls, but it’s not always size that counts. One must know the sex and maturity of the specimen, and examine the complex behavior of the individuals. Consider, for instance that the debate about H. floresiensis continues, wondering whether they were members of Homo with even smaller skulls. The Dmanisi skull shows a large face, protruding jaw, and large teeth. None of those are necessarily correlated to intelligence or lack of it. The person might look a little different walking down Broadway in a suit, but with upright posture and serious gaze, he would probably be accepted as human, no less peculiar than some from other countries.
One can only wonder, after this revelation, what will become of other alleged species of Homo, like the Denisovans, the Neanderthals, Heidelberg Man and the rest. Another paper in Science suggested that the Denisovan peoples migrated across the “Wallace Line” in Indonesia, suggestive of good navigational skills. Authors Cooper and Springer began by reminding readers of another recent upset: “The recent discovery of Denisovans and genetic evidence of their hybridization with modern human populations now found in Island Southeast Asia, Australia, and the Pacific are intriguing and unexpected.”
Not all paleoanthropologists are prepared to accept what Nature says about this pruning of the family tree that implies “three early human species were one” —
“Like so many finds, [the skull] adds to what we know, but does not necessarily clarify or simplify things,” says Robert Foley, a paleoanthropologist at the University of Cambridge, UK. Nevertheless, he notes, the results of the new analysis must change the way scientists think about the nature and magnitude of anatomical variation in early Homo.
Fred Spoor and Bernard Wood are particularly upset about the new lumping. Wood wants to compare other skeletal features besides skulls. He’s also worried that lumping could be the start of a destructive trend:
While he acknowledges that the Dmanisi humans are all likely the same species and can be difficult to categorize as Homo erectus or a separate species, he argues that it’s unreasonable to “bring the whole bloody house down” by lumping all early human fossils into a single lineage.
The house that Darwin built must survive the evidence thrown against it.
Update 10/20/13: Darren Curnoe wrote a caustic op-ed piece in Live Science about this latest upset. While trying to explain that Lordkipanidze’s theory is not the last word, though, Curnoe may have done more harm than good. He described the whole enterprise of paleoanthropology for the last 150 years as a series of sensational headline-grabbing contests by over-anxious individuals. “This headline-grabbing approach to publication has become one of the pitfalls of modern academia” is just one such comment. He also does damage to the process of interpreting skulls by showing the confusions of homoplasy (convergent evolution), confusions of age and bone condition, interpretation of traits, and other theory-laden rescue devices aimed at fitting bones into favored hypotheses. If Lordkipanidze were right, Curnoe says, paleoanthropologists would have to get rid of Homo habilis, Homo rudolfensis, Homo gautengensis, Homo ergaster, Homo georgicus, Homo soloensis, Homo pekinensis, Homo mauritanicus, Homo heidelbergensis, Homo rhodesiensis, Homo antecessor, Homo neanderthalensis, Homo helmei and Homo floresiensis, lumping all these into a single lineage, Homo erectus.
So, the entire ~2.4 million years of evolution of the genus Homo comprises, this new study proposes, at most two species: Homo erectus and Homo sapiens. These would both belong to a single evolutionary line rather than being separate twigs within a bush of species.
Most anthropologists would currently recognise at least nine and up to 17 species of Homo, so the pruning would be about as radical as one can imagine!
Curnoe considers this a throwback to mid-20th-century attempts at lumping. Whoever wins this particularly contest may find himself sitting on the wreckage of public trust in paleoanthropology. Do any of these headline-hunting fossil hunters know what they are talking about?
Update 10/28/13: Peter Line gave a creation interpretation about Dmanisi Skull 5 at Creation Ministries Intl. He thinks some of the African Homo designations are australopithecine apes, but the Dmanisi skulls fit within human variability.
As usual, the evolutionists are trying to put a positive spin on all this, but it’s just the latest episode of “Everything You Know Is Wrong,” the Darwin Early Man series that plays at least once each year. Consider how all the cover stories National Geographic touted in the 1950s and 1960s with their heroes Louis and Mary Leakey are mostly forgotten, material for the bird cage. New tales are always in demand. Rival teams keep trying to outdo each other for press prominence. The other teams gnash their teeth at the team currently in the spotlight, finding fault with the methods or worrying that the new claim will “bring the whole bloody house down” – implying, undoubtedly, it will give support to the creationists, who believe humans have always been humans (morphological variations notwithstanding), and are not descended from apes by unguided processes of natural selection. Leave the evolutionary paleoanthropologists be; they are the blind leading the blind. Their procedure is: (1) Fall into the ditch. (2) Brush off the dirt. (3) Rinse; repeat.