Distinguishing drift and selection empirically: "the great snail debate" of the 1950s

J Hist Biol. Summer 2008;41(2):339-67. doi: 10.1007/s10739-007-9145-5.


Biologists and philosophers have been extremely pessimistic about the possibility of demonstrating random drift in nature, particularly when it comes to distinguishing random drift from natural selection. However, examination of a historical case--Maxime Lamotte's study of natural populations of the land snail, Cepaea nemoralis in the 1950s--shows that while some pessimism is warranted, it has been overstated. Indeed, by describing a unique signature for drift and showing that this signature obtained in the populations under study, Lamotte was able to make a good case for a significant role for drift. It may be difficult to disentangle the causes of drift and selection acting in a population, but it is not (always) impossible.

Publication types

  • Historical Article
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Genetic Drift*
  • History, 20th Century
  • Selection, Genetic*
  • Snails