What past climate change can tell us about today

Did climate change shape human evolution? That is the question marine geologist and geochemist Peter deMenocal is trying to answer. He will be on the ASU Tempe campus April 29, as a participant in the Institute of Human Origins’ 30th Anniversary Lecture Series. The lecture will take place at 5:30 p.m. in Murdock Hall, room 101. The event is free and open to the public.

As a professor and vice chair of the Department of Earth and Environmental Sciences at Columbia University, deMenocal conducts research through Columbia’s Lamont-Doherty Earth Observatory, where Earth science is studied on a global scale.

deMenocal employs deep-sea sediments as “archives” of past climate changes to understand the paleoclimatic context of early human evolution. He uses geochemical analyses of marine sediments to understand how and why past climates have changed and to place contemporary climate change trends within the context of the prehistoric past. Ocean sediments accumulate slowly but continuously and provide faithful records of past changes in Earth climate and ocean circulation over a wide range of timescales, from centuries to millions of years.

In the Feb. 4, 2011, issue of Science, deMenocal posits that large-scale shifts in climate changed ecological structures and resource availability. In particular, notable hominin events—extinctions, formations of new species, and other evolutionary events—appear to be associated with changes in African climate in the past 5 millions years, including the extinction of Australopithecus afarensis (popularly know as “Lucy,” discovered by ASU paleoanthropologist Donald Johanson) around 2.9 million years ago, the emergence of robust australopiths with large jaws and grinding teeth near 2.7 million years ago, and the emergence of the larger-brained Homo lineage sometime after 2.6 million years ago.

Peter deMenocal is one of seven lecturers planned to bring renowned scientists and experts in human origins to the ASU campus to celebrate the Institute of Human Origins’ anniversary theme, “Becoming Human: 30 Years of Research and Discovery.”

“The Institute of Human Origins’ research spans the breadth of human origins science, from crucial discoveries painstakingly extracted from the earth’s sedimentary record to sophisticated, cutting-edge analysis of the evidence and its contexts,” notes institute director and School of Human Evolution and Social Change professor Bill Kimbel.  “Our 30th anniversary lecture series is meant to illuminate the fundamentally transdisciplinary arc of our science and, at the same time, point the way forward on the key questions concerning human origins.”

Future speakers will cover research in the earliest humans, the origin of the genus Homo, the origins of technology, Neandertals, and the origins of modern humans.

A full year of anniversary events has been planned, including the lecture series; a fall 2011 exhibition in the ASU Museum of Anthropology; an essay competition – “Letters to Lucy” – for elementary, middle, and high school students; and a final symposium and gala in April 2012.

For more information about this lecture or the 30th Anniversary events, visit http://iho.asu.edu/30th.

This lecture is cosponsored by the School of Human Evolution and Social Change Late Lessons from Early History Lecture Series and the Institute of Human Origins.