Wednesday, September 20, 2006

The amazing fossil of 'Lucy's little sister'

The stunningly complete skeleton of a three-year-old girl who lived 3.3 million years ago has been uncovered in Ethiopia. The child belongs to the species Australopithecus afarensis like the famous "Lucy", who was discovered in 1974. The young age of the so-called Dikika child promises new insights into the growth of early humans.
The new find is the most complete and important skeleton of an immature Pliocene hominin ever found, says Tim White of the University of California, Berkeley, who worked on the Lucy discovery. "The gist of the current paper is, 'Eureka, we have it'," he says.
A team led by Zeresenay Alemseged of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, spotted the first bones south of the Awash river on 10 December 2000. The team spent four field seasons scouring the area for every scrap of the skeleton.
Lucy was also found in the Awash region, which is famed for its early human fossils. Many anthropologists think A. afarensis was ancestral to the genus Homo, though its exact position in the human family tree remains a matter for debate.
Alemseged's team believes that a flood rolled the child's body into a ball and buried it in sand soon after her death, before the bones could be weathered or pulled apart by scavengers.
Analysis of the skeleton has barely begun because the upper parts, including the skull, shoulder blades, collarbones, ribs and backbone, are still largely encased in a block of hard sandstone. However, a CT scan of the skull revealed tooth development matching that of a three-year-old, the team reports in Nature (vol 443, p 296).
"At least 50 per cent of the skeleton is there, but more importantly we have the face and brain endocast, and the whole skull, telling us clearly how the [child] looked," says Alemseged. He estimates the brain size was 330 cubic centimetres, between 63 and 88 per cent of the size of an adult of the species. This hints at brain growth slower than in chimpanzees, whose brains have reached 90 per cent of adult volume by age three. A. afarensis may therefore have begun evolving the slower brain development characteristic of modern humans.
The exposed leg bones show the child walked bipedally like Lucy. In contrast, the shoulder blade "in some ways resembles young gorillas", says collaborator Bill Kimbel of Arizona State University. That supports the inference from Lucy's long arms that she was a better climber than modern humans. During the girl's lifetime the environment was a mosaic of forest and savannah, so the species may have gathered food and slept in trees, but walked from place to place.
Another key discovery is a hyoid bone, which is found in the throat and in humans is involved in speech. Until now, only one fossil hyoid has ever been found, and it was from a Neanderthal. The Dikika hyoid resembles an ape's, suggesting speech had not begun to evolve in A. afarensis.
Alemseged believes much information can be gained once the skeleton is freed from its stone casing. "A clear picture will emerge of how baby human ancestors were built, and how they grew up," he says.
From issue 2570 of New Scientist magazine, 20 September 2006, page 8


At 12:22 PM, Blogger Seamus said...

Isn't it funny how digging up dead apes brings such renown and prestige?

I'm reminded of the wise words of Robert Koons:

"We're still waiting for Darwin's Newton: for a theorist who can take Darwin's proposal and produce even one hypothesis which specifies, step by step, the genetic changes that had to take place, the embryological alterations that these changes produce, and the quantifiable selective pressures that enable each new step to reach a significant proportion of the population."

It's all too true. We're still waiting for even one example of evolution that's based on actual science. I've said before that evolutionary scientists are just overpaid story-tellers (I would call them liars, but I don't believe they deliberately deceive people). This discovery is a case in point.

Evolutionists, of course, would protest to Koons's statement. "Evolution is a FACT!!!", they scream. Well, if it really was a fact they should have no trouble providing us with a single example. The problem is that what they present as examples are just stories. Stories of how one creature evolved into another are plentiful; but stories aren't science.

Making evolution a science is theoretically simple: Propose and test a falsifiable hypothesis of how creature A specifically evolved into creature B. Such a hypothesis would include the specific genetic makeup of the original creature, the specific genetic mutations that take place within that creature, the specific causes of those mutations, and the specific morphological and embryological changes that each of those mutations create. It would also need a comprehensive and specific description of the environment, such as the biome/climate/food chain/diet/etc..., upon which it could make very specific conclusions about why each specific mutation was acted upon by natural selection. This theory would contain the exact and specific phenotypical and geotypical steps from creature A to creature B and would completely explain the exact relationship between the genotype and phenotype and the specific effects each mutation would have on both. Such a theory thus proposed is actually testable, easily falsified or verified by the data.

Not only have no such theories been proposed, but our current level of scientific explanation is simply incapable of such a complete theory. This doesn't excuse science from making such a theory, it just forces them to admit that what they have now is mere hypothesis. This is exactly what they refuse to do, however. They insist that what they have is demonstrable fact. They deceive themselves.

Let's get back to the story at hand. The authors/discoverers expect us to believe that they have found a young Australopithecine. That, in itself, isn't a big deal. They then decide to claim that this sheds light on human evolution. Whoa, now. Notice how none of their supposed evidences of human evolution are specific, falsifiable, or testable. All they have is a collection of skeletons and artifacts that they claim demonstrate a chain of evolutionary steps. That's a nice story, but where is the science? Where are the falsifiable/verifiable specifics?

Notice also that every major paleoanthropological find redefines evolutionary theories to some extent. This should be embarrassing! Every time they decide to change the theories, they inadvertently admit that their previous theories were either partially or completely wrong. They also inadvertently admit that they still lack the evidence they need to propose an actual theory worthy of scientific investigation.

What we're left with is a very small amount of data compared to the embellishments lavished upon it. As long as evolutionary science insists on promoting stories as facts, we are hopeless. Only by a thorough and independent audit of paleontology as a whole could we even begin to salvage what is left of true science.


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