Why Darwin Matters_ The Case Against Intelligent Design - Michael Shermer [68]
But the bush is not so bushy, says White. The problem lies in the difference between “lumpers” and “splitters” in species classification, and in the social pressures to publish extraordinary new discoveries. If you want to get your fossil find published in Science or Nature, and you want the cover illustration, you cannot conclude that your fossil is yet another Australopithecus africanus, for example. You had better come up with an interpretation indicating that this new find you are revealing to the world for the first time is the most spectacular discovery of the last century and that it promises to overturn hominid phylogeny and send everyone back to the drawing board to reconfigure the human evolutionary tree. Training a more skeptical eye on these fossils, however, shows that many of them belong in already well established categories. White says that the specimen labeled Kenyanthropus platyops, for example, is very fragmented and is most likely just another Australopithecus africanus. “Name diversity does not equal biological diversity,” White elucidated.
White concluded his talk with a fascinating discussion of the recent discovery of fossil dwarf humans on Flores Island in the Malay Archipelago, located on the outside of Wallace’s Line, meaning that even during the last ice age they could have gotten there only by boat. (White did note, however, that after the 2004 tsunami in this area, people were rescued from large floating rafts of natural debris, so it is possible that the founding population of Flores humans rafted there by accident and not by design.) Found in Liang Bua cave, the type specimen of Homo floresensis was dated at 18,000 years old, meaning that they had to be modern humans because all other hominid species had long ago gone extinct. But with a cranial capacity of only 300cc—about the same size as that of Lucy or a modern chimpanzee—they were able to fashion complex tools (and possibly boats) with tiny brains; the implication is that brain architecture, not size, is what counts for higher intelligence. A second published specimen put to rest the pathology hypothesis that Homo floresensis was a microcephalic human. The best evidence, says White, points to insular dwarfing, a rapid punctuation event that led to the shrinkage of these isolated people. Such dwarfing effects can be seen on this and other islands, where large mammals get smaller (like the dwarf elephant) and small reptiles get larger (like the Komodo Dragon). The chances of any living members of this species still existing in the hinterlands of Flores are extremely remote, but some observers have noted that the indigenous peoples of Flores recount a myth of small hairy humans who descend from the highlands to steal food and supplies.
Where Did Modern Humans Evolve?
Young Earth creationists have a ready-made answer to this question—the Garden of Eden—and they accept the biblical story of Adam and Eve as factual history instead of mythic saga. IDers, by comparison, avoid all such biblical references and argue simply that there is no evidence for human ancestry and thus there must have been a divine spark of humanity miraculously inserted into one hominid species. The evolutionary story is more complex, says University of Cambridge professor Peter Forster, an expert in archaeogenetics, who demonstrated how prehistoric human migrations can be traced by mitochondrial DNA (mtDNA) through the maternal line of modern humans.
Forster outlined our migrational history over the past 200,000 years as follows: Between 190,000 and 130,000 years ago, a single