Tuesday, December 17, 2013

Tool-using and dead-burying cavemen

Two more news stories released yesterday from the Proceedings of the National Academy of Sciences support the view that human ancestors were just as human as modern man, anatomically and culturally, challenging the common perception that "cavemen" were relatively unintelligent and underdeveloped.

A comparison of the third metacarpal of an ape, an
australopithecine, a modern human, and the Kaitio
specimen.  The arrows point to the styloid process.
Credit: University of Missouri.  Image source.

Human Hands


One of the features that distinguishes humans from apes is our extensive tool use, and the design of our hands reflects this.  The bone that connects our middle finger to our wrist, the third metacarpal, has a distinct projection at the wrist joint that reinforces the bone structure, allowing for stronger grips and more effective tool use without damaging or dislocating our fingers.  This projection, called the styloid process, is not found in apes, but only in Neanderthals (Homo neanderthalensis), modern humans (Homo sapiens), and a few other close relatives.

Now, a third metacarpal found in Kaitio, Kenya, is causing a stir in the anthropological community (original publication).  Dated at about 1.42 million years old, the bone is attributed to Homo erectus, a species thought to be the direct evolutionary ancestors of Neanderthals and modern humans.  It is virtually indistinguishable from a modern human third metacarpal, including the presence of a styloid process.  This feature and the presence of stone tools found nearby indicate that Homo erectus could make and use stone tools, pushing this development back by 600,000 years on the evolutionary timeline.  In the creationist view, Homo erectus were fully human, an early descendant of Noah, so it is expected that they were physically and mentally capable of fashioning stone tools, which was probably frequently done while migrating across the land from Babel.

Neanderthal Funerals


In 1908, the remains of another ancient human group, the Neanderthals, were found buried in a cave in France and dated at 50,000 years old.  Initially, the site was interpreted as an intentional burial ground, but controversy arose due to the view that Neanderthals were not yet mentally developed enough to bury their dead.  In an attempt to settle the issue, a group of scientists studied the burial sites for twelve years and released their results yesterday.  It turns out that the sites do show signs of intentional, rather than natural, burial.  The skeletons show no signs of disturbance or weathering, unlike other animal bones found in the cave, and a geological analysis showed that the grave did not form naturally in the cave floor.  William Rendu, lead author of the study, commented that "while we cannot know if this practice was part of a ritual or merely pragmatic, the discovery reduces the behavioral distance between them and us."

The evolutionist interpretation of Neanderthals has gradually portrayed them more and more like modern humans, with some scientists arguing that they should be classified as the same species.  Studies like this one only close the gap further.  Creationists, of course, are happy with the results, viewing Neanderthals as a group of humans that migrated from Babel and adapted to the cold climates of the European Ice Age.  Abraham, a possible contemporary of Neanderthals, buried his wife Sarah in a cave, so it is likely that cave burial was more or less a universal convention at the time.

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