Prof Sydney Brenner, the 2002 Nobel Prize winner for Physiology/Medicine and a STIAS visiting fellow, and world-renowned anthropologist and palaeontologist Prof Nina Jablonski, received honorary doctoral degrees from Stellenbosch University at a graduation ceremony on Wednesday 10 March 2010. They both also presented public lectures at STIAS.
On Tuesday 9 March Prof Jablonski presented “Why human skin comes in colours”. This lecture was coordinated with the African Genome Education Institute as part of their Darwin lecture series and was sponsored by Naspers.
An intriguing lecture by Prof Jablonski’s expanded upon the following abstract: “Skin colour is one of the most obvious ways in which people vary, and has been used in the past as a basis for the biological classification of humans into races. Our research work and that of many other groups have demonstrated that skin pigmentation is a biological adaptation that regulates the penetration of ultraviolet radiation (UVR) into the skin. Skin pigmentation is an evolutionary compromise between the conflicting demands of protection of the skin against UVR and of production of vitamin D by UVR. This compromise represents one of the best examples of evolution by natural selection acting on the human body. In the history of the genus Homo and of our species, Homo sapiens, skin pigmentation has been a highly labile trait. Similar skin tones have evolved independently numerous times in response to similar environmental conditions. Because of this, skin colour is an inappropriate basis for the classification of humans into groups.”
Prof Brenner has been a visiting fellow of STIAS since 2005. On Thursday 11 March he presented a STIAS Lecture on “Reading the Human Genome: the reconstruction of the past”. In typical style Brenner captivated his audience, speaking without notes or slides: “I have no slides for this presentation. I haven’t mastered PowerPoint yet and don’t want to. One good phrase is worth a thousand PowerPoints”.
He outlined his idea for a novel method of analysing a single genome to tell whether it is at mutational equilibrium. If it is at equilibrium it carries no information from the past; if is not then it does. In fact, there are traces in a human genome of organisms that lived as much as a billion years ago.
Caption: Prof Hendrik Geyer (STIAS Director) with Profs Nina Jablonski and Sydney Brenner after they had received honorary doctoral degrees from Stellenbosch University. (Photo: Anton Jordaan)