ST ANDREWS SCIENTISTS DATE THREE MILLION-YEAR-OLD HUMAN FOSSIL

ST ANDREWS SCIENTISTS DATE THREE MILLION-YEAR-OLD HUMAN FOSSIL
GEOSCIENTISTS at the University of St Andrews have dated an early human fossil discovered in a remote part of Ethiopia and unveiled to the world this week.
The geological dating techniques, which dated the sediments surrounding the remains at 3.3 million years old, were carried out by researcher Dr Jonathan Wynn at St Andrews, and Dr Diana Roman of the University of South Florida.
Jonathan, now based at the University of South Florida, was working under the supervision of Professor Michael Bird, who developed the dating technique used to age Homo floresiensis, the new species reported to the world in 2004.
The most recent discovery made in the Afar region of Ethiopia is a very well preserved specimen of a juvenile female, Australopithecus afarensis, that was approximately three years of age when it died. Jonathan's analysis of the surrounding sediments, soils and fauna paint a picture of the environment in which the fossil lived and died.
With the establishment of a long-term record of local environmental change, the research also tells us about the effect of the global climate on the course of human evolution in this part of Ethiopia.
He told the Citizen: "Because we have a very complete geological picture for the entire area, this is indeed the most interesting part of the story, which goes well beyond providing the age of the fossil.''
While the Leipzig-based anthropologist Dr Zeresenay Alemseged began the 'Dikika Research Project' in 1999, the initial discovery of the fossil was made by a member of Ethiopia's National Museum in 2000.
Working in collaboration with Zeresenay, Jonathan has been involved in providing the geological context since 2002. During this time, he spent up to two months a year in the field at the site at Dikika, to examine the area where the fossil was discovered. By building up details of the surrounding area, Jonathan and fellow researchers were able to get a clearer picture not only of the fossil's geological age, but also the environmental conditions in which it lived.
Jonathan has been able to establish that the hominin lived in a 'unique, lush environment' surrounded by flowing water, forests, grassland and open vegetation, but which was also affected by widespread volcanic eruptions.
Animal fossils found in the surrounding area by palaeontologists from France and the U.S. reveal a range of habitats appropriate for hippos, crocodiles and snails, which would have lived near water, to the white rhino and relatives of the wildebeest that would have inhabited the more open parts of the landscape.
Since the international research team knew 'next to nothing' about the geology of the discovery area, Jonathan's role as a geologist was to construct a complete geological framework for the entire area (100 square kilometers), to establish the age of the fossil, and the age of sediments in the entire area, in addition to the nature of how the whole package of sediments are exposed across the region.
22 September 2006