Becoming Human

Philip V. Tobias, a world renowned paleoanthropologist, equally at home in the field or in his office preparing descriptions, has died at 87. He succeeded Raymond Dart as department head at the University of the Witwatersrand in Johannesburg, South Africa. In his long and fulfilling career he worked with the Leakeys at Olduvai Gorge and fought apartheid at home.

This is the title of a paper appearing last week in the journal Nature.  A careful examination of fossilized tooth enamel and a plaque from this intriguing (and controversial) taxon discovered at a site called Malapa in South Africa in 2008, provides a detailed insight to the diet of one species of hominin at a particular place and time.

Researchers investigating thin layers of limestone deposited on ancient cave paintings suggest in a paper published in Science last week two intriguing possibilities: the famous cave paintings in France and Spain may be as much as 15,000 years older than previously established; Neanderthals may have been cave painters as well as were the anatomically modern humans who replaced them.

Recent years have seen the decoding of the human genome, then that of our closest human relative, now extinct, Neanderthals (Homo neanderthalensis). The Chimpanzee genome has been analyzed and now is the turn of the often overlooked sister species to Chimpanzees, the Bonobos.

“It’s a lovely little foot” declared Don Johanson, upon learning of a  new fossil find in Ethiopia. Johannes Haile-Selassie and others announced in the March 28 issue of the journal Nature the recovery of a partial foot from the Burtele area of  Ethiopia. Eight of the normally 17 bones of the hominin foot were found eroding from sandstone dated to 3.4 million years ago.

Adaptations, large and small, are occurring at a regular rate in all species and demonstrate how evolution by natural selection works.    The changing shape and strength of the beaks of finches in the Galapagos; the darkening color of moth wings in England as the Industrial Revolution took hold; and the recent loss of sound produced by crickets rubbing their wings together in Hawaii are compelling examples of adaptations.

The award winning website BecomingHuman.org now has a Facebook page - check it out. Not much now but watch it grow!

The phenomenon of sociability in primates, including our own species, is examined in a paper published in Nature last month and discussed in the science section of the New York Times this week.The social brain hypothesis - “... that intelligence and brain volume increase with group size because individuals must manage more social relationships” (quoted from the New York Times) - is challenged in this new paper.

Reports from South Africa in recent months have shed new light on the activities of members of our species at critical junctures in human evolution.  The first of these was a series of papers elaborating upon the initial announcement of the discovery of a new species(Au. sediba) which is said to be possibly an example of early Homo; this was followed by further evidence of the use of ochre as decoration; and in the past two weeks evidence of using tree boughs as bedding material.

The  re-dating of the tooth of an infant found in Italy in the Sixties, and the more recent find of a mandible with three teeth in England, have pushed back the time it is thought our species, Homo sapiens, migrating out of Africa arrived in Europe.