Early humans and plant evolution: the Annual Geography Lecture

Posted by mjs76 at Mar 03, 2010 01:45 PM |
Ancient humans are the subject of this year’s Annual Geography Lecture, a free public event on Thursday 4 March. Professor Julia Lee-Thorp from the University of Bradford will speak on ‘Emergence of the C4 World in Africa: Patterns of adoption and adaptation by African fauna including early hominins.’

So, er, what is the ‘C4 world’? Well, we all know that plants use carbon dioxide during photosynthesis but there are actually three different biochemical methods that different groups of plants use: C4, C3 and CAM. C4 is the most recently developed of these, first appearing about 25-32 million years ago but only becoming really widespread about six million years ago, by which time the first proto-humans were wandering around.

C4 developed independently in more than 40 different plant groups - notably many grasses and crops - as a response to the spread of such plants from forests to open plains. The C4 method is much more efficient and better at retaining water than C3 so is an evolutionary in a hot, sunny environment. There's a neat, plain English summary of C4 evolution on palaeobiology.org.

Why should this bother an archaeologist like Professor Lee-Thorp? Because her interest lies in palaeo-anthropology and specifically the diet of Australopithecus, the early hominid which subsequently evolved into Homo sapiens. The development of our evolutionary line is inextricably linked to the evolution of the plants that formed much of our ancestors’ diet, including not only developments such as teeth but also our upright stance.

If this all sounds brilliant and fascinating – which it is! – you can learn more from Professor Lee-Thorp’s lecture which takes place at 4.15pm on Thursday 4 March in Lecture Theatre 10, Bennett Building, University of Leicester.