Life’s little Joke

Evolutionary biology is a field plagued by more misunderstanding and misrepresentation than practically any other in science. Adaptive evolution by natural selection is a simple concept, yet the ways in which selection operates are exceedingly subtle and the patterns it generates are easy to misinterpret. Especially in India, the meagre treatment that evolution gets in biology curricula is rife with misinterpretations and over-simplifications; it is also shockingly out of date by over half a century. Stephen Jay Gould wrote extensively and elegantly about misunderstandings of pattern and process in evolution. In the essay reproduced here, which appears as Chapter 11 in ‘Bully for Brontosaurus’, he takes up the tale of the evolution of modern horses, a tale that is familiar to most of us from high school biology texts. Gould shows in his inimitable style how the prejudiced notion of evolution leading to some kind of clear progression up a ladder of increasing perfection was projected onto the data on fossil horses, leading to figures reproduced in biology texts world-wide as cononical examples of adaptive evolution that are, nevertheless, plain wrong.Amitabh Joshi