"The implication of this dental difference is that the newly evolved hominids were living in a radically different, less competitive social structure than seen in modern chimps, he said."
"The researchers note two other sites that have yielded fossil hominids from the same 5- to 6-million-year period. One group of fossils found in 2002 in Chad has been named Sahelanthropus tchadensis, while others found at a Kenyan site in 2000 have been dubbed Orrorin tugenensis. All of these fossils are sufficiently similar that they should be included in the same genus as Ardipithecus kadbba, the team argues."
Big Bang Theory Of Human Evolution?
"All the available evidence supports an 'Out of Africa' theory, that humans first evolved in Africa about two million years ago, then spread to other regions of the world," says John Hawks, first author of the paper and now an assistant professor of anthropology at the University of Utah. "This original population lived before humans colonized regions outside of Africa. In fact, it was the act of becoming human that made these colonizations possible."
"A second reason for suspecting that a population bottleneck led to a rapid genetic reorganization that started the process of human evolution comes from archeological evidence of a series of behavioral changes suggestive of a new adaptive pattern of hunting, gathering and scavenging. "Body size is a key element in these behavioral changes," the authors note, "because of the locomotor changes that large body size denotes, and the increased metabolic resources it requires." These behavioral changes are far more massive and sudden than any earlier changes known for hominids, they point out.""Many details of subsequent human evolution over the period of the ice ages remain unclear, but one certain finding from both anthropological and genetic data is that there was no later time when the size of the human species became small again," says Hawks.
Early Hominids May Have Behaved More 'Human' Than We Had Thought
"Previously skeptical, an Ohio State University anthropologist now supports the idea that the minimal size differences between male and female pre-hominids suggest that they lived in a more cooperative and less competitive society. The evidence centers on the extent of sexual dimorphism – differences in size based on sex --that existed among these early primates and what it suggests about the social structure of these creatures."
"Paleontologists knew that there were minimal size differences between males and females since Homo sapiens evolved but the fossil record is so sparse, they were unsure of whether pre-Homo species showed more of less sexual dimorphism."
"The comparison showed that the sex-based size differences among the fossils at Site 333 were no greater than those for modern humans, suggesting that the same kind of modern social structure with cooperating males also occurred in the days of Australopithecus afarensis."