Oct. 24-26, 2009, Yingjie Overseas Exchange Center, Peking University, Beijing, China中文版

Darwin and the tree of life

Michael J. Benton

Department of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, United Kingdom

Abstract

Charles Darwin is famous for having worked out the theory of evolution by natural selection, and many regard this as his main, or even sole, contribution in the ‘Origin of species’, published in 1859.  However, equally important was his realization that the evolution of life can be pictured as a great branching tree, later called a phylogeny by Haeckel, and his characterization of macroevolution as ‘descent with modification’. Tree thinking went hand in hand with, or even preceded, Darwin’s full development of the theory of natural selection – his observations in South America convinced him of vertical relationships (through time) and his observations on the Galapagos and other islands convinced him of horizontal relationships (geographic variation).  In 1838, he drew his first phylogenetic tree in his notes.  Subsequently, the tree has been an icon of evolution, but it is only relatively recently that tree thinking has become pervasive in biology and palaeontology.  This came with new, objective, methods for constructing the tree – cladistics in the 1960s and 1970s, and automated genome sequencing in the 1980s and 1990s.  Both methods have led to an explosion of published phylogenetic trees in the scientific literature, following an exponential trajectory.  Before 1990, very few papers in general molecular, ecological, or behavioural journals were supported by a tree; now, virtually everything in biology is tested against a phylogeny. Further, tree-making has now become a major enterprise in its own right – the ‘Tree of Life’ project – with implications for all biologists, and strong links to the practical and political understanding of biodiversity conservation.  The very existence of trees, with their inclusive hierarchical structure, is a key proof of evolution.  Further, the concordance of trees with the order of fossils in the rocks is further proof of evolution, as well as proof that the methods of tree-making and of fossil collecting and dating are broadly correct.  Darwin’s phylogenetic tree has at last taken its true place of importance in modern evolutionary thinking.

Michael J. Benton

Department of Earth Sciences, University of Bristol, Bristol, BS8 1RJ, United Kingdom

Biography

Michael Benton is Professor of Vertebrate Palaeontology at the University  of Bristol, UK.  His major current interests are the origins of novelty in evolution, mass extinctions, and dinosaurs.  He has written more than 200 scientific articles in technical journals, including 15 in Nature, and Science, as well as fifty books, including technical volumes, textbooks, and popular books.  He is a Fellow of the Royal Society of Edinburgh, and was an Edward P. Bass Distinguished Visiting Scholar at Yale  University in 2009.  Among current projects, he is working on the end-Permian mass extinction in the red beds of Russia, exceptional preservation of feathers in the Jehol Group (with colleagues from IVPP, Beijing), and diversity and disparity in evolutionary radiations of various groups of vertebrates.