Sunday, June 04, 2006

Analysis: Dmanisi Skulls vs. Lubenow

Upon the publication of the second edition of Bones of Contention, Talk Origins waxed arrogant against Lubenow's supposed denial of the Dmanisi skull data. In fact, on their page discussing Dmanisi hominid D2700 in particular they include another jab at Lubenow toward the bottom.

So why does Dmanisi matter? Evolutionists claim that it bridges the gap between the small brained Australopithecus/Homo habilis and the larger brained Homo fossils like H. erectus and higher. Lubenow does state in both editions of his book that Human cranial capacity, including H. erectus, can extend from 700cc to upwards of 2200cc (although he does state that normal Humans don't go below 775cc). The three Dmanisi skulls, which evolutionists label as H. erectus and claim that they are all morphologically similar enough to be declared members of one population, have cranial capacities of 600cc, 650cc, and 780cc (by Talk Origins estimates). It seems like the evolutionists have a point. If Lubenow claims that the gap between man and ape is a clear one (in terms of cranial capacity), then these skulls (if all the same species) blur that line.

Before I go on, I will let Lubenow speak for himself:
"There can be problems in interpreting whether or not a fossil is human based on brain size. My own rule is that, normally, no human fossil brain should be smaller than the smallest normal brain today (about 775 cc for fossil adults), but it could be larger than human brains today. Undisputed evidences of culture, such as in burials, can help discriminate between humans and nonhumans. There is a condition in the fossil record known as gigantism. A giant ape could have a brain size approaching the smaller human brain sizes. In this case, items that could help in discriminating between human and ape are the presence or lack of culture, the proportion of face size to brain size, extreme prognathism, a large sagittal crest, and other items common in ape morphology."
Lubenow surely anticipated their argument, and he does indicate that it is possible that an ape could approach the low range of human cranial capacity. Therefore, Lubenow's statement could allow for the Dmanisi hominids to be apes, one of them with an abnormally large cranial capacity. Lubenow does not directly claim this, however; in his charts he labels the smaller skulls as H. habilis and the larger skull as H. erectus. Realistically neither he nor the evolutionist can prove his point conclusively; the skulls could represent a homogeneous or heterogeneous group. I do admit, however, that the evolutionist has good evidence for his side since the skulls are from the same site and same supposed age and thus could reasonably be considered one population.

It should be noted that Lubenow does not consider the species distinctions of hominid fossils to be valid. He considers all Homo, except for habilis to be Human. His fossil charts use evolutionist dates and evolutionist taxonomy, except in a few documented disagreements, so his charts showing that the skulls fall into different taxa do not necessarily indicate that he places them in such categories. I can't speak for him authoritatively, though, and in the absence of contrary information we should assume he places them in separate taxa intentionally.

It is also important to note that the Dmanisi skulls, dated at around 1.9 m.y.a., are too late for the supposed transition in cranial capacity. From the East Rudolf (Turkana) area there are already fossils, also dated around 1.9 m.y.a, that fall within a much larger size range (such as KNM ER 1470, 1472, 1481, and 1590). In other words, if the Dmanisi skulls are supposed to exhibit a transition from a smaller to larger brain/body, why do populations exist at exactly the same time that have already well surpassed this supposed transitional point? The fossil record does not support such a transition.

An even more intriguing solution to this problem comes from a different source entirely; a source too recent to appear in Lubenow's 2004 work, so I'm not sure what he would say about it. I can, however, make a few guesses.

H. floresiensis: The greatest defense against evolution is surely the fossil record itself. H. floresiensis is the name that evolutionists have given some surprising fossils from the Indonesian island of Flores. These fossil hominids have an extremely small cranial capacity. The most complete skull, LB1, is only 380cc. This sounds like an australopithecine so far, but they have dated these fossils at only 18,000 y.a.! There is clearly a problem here.

Since evolutionists are particularly fond of assigning fossils to categories based on their age (even if the morphology does not fit), they claim that this is a late surviving member of H. erectus. As for the skull size, (WAY out of H. erectus range), they call H. floresiensis a "dwarf human". Additional evidence includes the association of tools, fire, and hunted game with these fossils. There is also possible evidence of sea travel, deduced from their seclusion on an island.

So let's analyze this. Evolutionists claim that fossils around 1.9 m.y.a. demonstrate a transition in cranial capacity from about 600cc to 780cc. To find fossils well over 1.8 m.y. younger, but with a cranial capacity even smaller rules this transition out entirely. Sure these fossils are on an island, but they originated somewhere else and they apparently hadn't evolved on the evolutionist's sacred time scale. So how do they deal with this? Hmm, it can't be Australopithecus, it can't be a transitional fossil, so it must be...a dwarf! Of course, if the fossils don't fit, it must be some freak of nature! Evolution is so patently obvious that any data not supporting it is just a mistake. (Do you catch my sarcasm?)

Evolutionists think they can get away with having their cake and eating it too:

1.) If H. floresiensis is a dwarf species, then so can every other small cranium. In fact, Dmanisi could be a dwarf population too. By using NON-EVOLUTIONARY explanations to justify a fossil's morphology, they admit that evolution is not necessary to explain morphology at all.

2.) If H. floresiensis is not a dwarf species, then it shows that hominids with extremely small cranial capacities never evolved into hominids with larger cranial capacities. They were still just as small 18,000 y.a. on the evolutionist's time scale.

But wait, there's more. The Flores fossils are stated to be around 1 meter in height, small in skull and body. One study of an arm bone there, however, indicates that the hominid it came from could have been 1.5 or 1.6 meters in height. That's approaching the size of modern humans, though still very short. This could potentially indicate that H. floresiensis lived alongside more modern (morphologically speaking) hominids, and again destroys any vestige of evolutionary transition. It could also lend credence to the idea that these were microcephalic humans. Either way, it hurts rather than helps evolutionary theory.

The evolutionist is assured, however, that everything is ok. Talk Origins states:
"This discrepancy [the arm bone] will doubtless be thoroughly investigated"
They speak as if further investigation will somehow relieve the discrepancy. Given the tendency of evolutionists to fudge on things like morphology, taxa, and dates, when under the burner I'm sure they'll work something out. They also reassure us by saying:
"The discovery of H. floresiensis does not change the broad picture of human evolution, including our lineage - it was certainly not ancestral to us."
Their evidence for the reassurance? I didn't see any. Their evidence that these fossils are not ancestral to us? Again, I didn't see any. It only follows from their theory that such a small brained creature had nothing to do with the grand H. sapiens.

Back to Lubenow: Given all this information we could claim that either some apes could theoretically approach small human cranial size or that some extremely small humans could approach ape cranial size. Are the Dmanisi fossils humans or apes? I don't really know. How about the Flores fossils? I don't know about those either. But either way a person decides (apes or humans), the explanation clearly does not depend upon any sort of evolution. Lubenow prepares his readers for this sort of slippery evolutionist reasoning. I grant the evolutionist his point that Lubenow's line of demarcation between human and ape at 700-775cc could be called into question for these unusual (and exceptional) fossils; but, in my opinion, Lubenow remains unscathed.

These fossils surprised creationists and evolutionists alike, but I think they cause real problems only for evolution. Maybe our distinctions based on cranial capacity need to be revised. Maybe these skulls are the exception to the general rule. Maybe they are just all apes. Conclusive proof isn't available for either side of the argument. I'm not a paleoanthropologist, but I can easily see the problems that these fossils cause for the theory of evolution.

1 Comments:

At 11:14 AM, Blogger michelladams said...

I'm very proud of both this blog and what you stand up against the liberals for! You rock my world.

 

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