Evolutionary biologists are ever adapting to progress in science | Letter

Many discoveries since the modern synthesis have been incorporated into evolutionary biology without substantially changing its major tenets, write Brian Charlesworth, Deborah Charlesworth and Jerry Coyne

Stephen Buranyi's article (Do we need a new theory of evolution?, 28 June) discusses whether there are serious problems with the widely accepted view of evolution developed in the 1930s and 1940s, often called the modern synthesis. This article does not, however, give an unbiased or accurate account, making statements such as the theory dictated that, ultimately, genes built everything", and implying that authority figures in the field imposed a party line". Buranyi also suggests that its most ambitious claims - that simply by understanding genes and natural selection, we can understand all life on earth" have been dropped or greatly modified.

Evolutionary biologists made no such claims. The modern synthesis combined evidence about how inheritance works with Darwin's idea of natural selection. It showed how adaptive features of organisms, such as the eyes, wings and placentas mentioned by Buranyi, can evolve through natural selection acting on mutations, producing changes in the genetic composition of populations that, over time, can transform initially poor functions into complex adaptations. A famous 1994 paper by Dan-Erik Nilsson and Susanne Pelger showed how a light-sensitive patch can evolve into a light-focusing eye. Similarly, the evolution of placentas presents no major difficulty, as placenta-like organs have evolved independently in several groups of animals, with examples of intermediate structures.