Leakey lectures examine evolution

The Leakey Speaker Series on Human Origins continues at Caltech with three lectures based on the latest in anthropological and archeological research. Presented by leaders in their respective fields, the lectures provide insights into the ways that our earliest ancestors lived, and delve into the mysteries of the evolution of the human race.

The dig site Olorgesailie in Kenya has provided Richard Potts, the director of the Smithsonian Institution’s Human Origins Program, with a detailed snapshot of early human life. Since Louis and Mary Leakey began work there in 1942, the Paleolithic-era site, which was inhabited by early humans some 500,0000 years ago, has given up a rich collection of fossils, most notably Acheulian hand axes.

These primitive yet effective tools have provided paleoanthropologist Potts and his team with the data to conduct a comparative study of Olorgesailie with an early settlement in China. In the lecture “The Adaptable Hand-Axe and Human Origins,” Potts will show how recent discoveries support a novel theory that hand axes were adaptable to the users’ needs and in widely varying ecologies.

This lecture will take place on Wednesday, February 25.

The point at which hominids made the transition as a species from Australo-pithecus to Homo has been identified at about 2.5 to 2 million years ago. In 1962, the Leakeys dated early hominid fossils associated with stone tools at 1.8 million years ago. These hominids were subsequently named Homo habilis.

In the lecture “The Transition from Australopithecus to Homo,” Berhane Asfaw, director of the Middle Awash Research Project, will speak about the oldest discovered bones and stone tools in Ethiopia. These relics have been associated with a subset of Australopithecus, a finding indicating that the use of stone tools may have preceded the arrival of the earliest members of genus Homo. Asfaw will deliver his talk on Wednesday, April 7.

Few things survive in the fossil record, and human skin is not one of them. Yet the study of the evolution of human skin has not received serious study—until now. Nina Jablonski, the Irvine Chair and Curator of Anthropology at the California Academy of Sciences, has used epidemiology, physiology, and remotely sensed environmental data to study the origin of skin-tone variation.

In “The Evolution of Human Skin Coloration,” Jablonski will demonstrate how human skin color is a product of natural selection. Although skin must protect individuals from damaging ultraviolet radiation, these rays are necessary for the synthesis of vitamin D; therefore melanin pigmentation represents a compromise between these two needs. Jablonski will present her talk on Wednesday, May 19.

All lectures will take place in Beckman Auditorium and are set to begin at 8 p.m. The cost is $12 for the general public and $5 for students. Series discounts are available. For further details, contact Caltech Public Events at (626) 395-4652 or visit www.events.caltech.edu.
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