Rapid diversification despite morphological stasis: A snail's pace in a snail's place?

August 6, 2013

Evolutionary biologists at the National Museum of Natural History of the Smithsonian Institution and Ghent University (Belgium) have found an unusual system that allows narrowing the gap in the study of evolutionary processes, working on living African freshwater snails and their fossil ancestors.

Species diversification regularly occurs too fast to be accurately recorded in the fossil record but usually too slowly to be readily observed in . The study of evolutionary radiations is thereby confronted with a gap between the timescales and approaches used by biologists and paleontologists. Although they are difficult to study some of these processes influence our daily lives in various ways. The emergence of pesticide or antibiotic- of organisms are examples of rapid evolution, whereas the endangered status of species like the result from the inability of these species to adapt sufficiently rapid to changing conditions.

Evolutionary biologists at the National Museum of Natural History of the Smithsonian Institution and Ghent University (Belgium) have found an unusual system that allows narrowing the gap in the study of evolutionary processes. Working on living African freshwater snails and their fossil ancestors, they document rapid diversification since massive lake level fluctuations that occurred during the Ice Ages. Despite the ever changing environment in which these snails live, morphological characters studied within a lineage of fossils did not change much over five thousand years.

Different morphological characters appear to have behaved differently, with some hardly changing over thousands of years, and others, like body size, changing a lot (the smallest species is less than 1/3 of the size of the largest one). It appears that morphological stasis is a dominant evolutionary pattern, even in young and diversifying clades.

Explore further: Evolutionary mode routinely varies amongst morphological traits within fossil species lineages

Related Stories

Recommended for you

Cow gene study shows why most clones fail

December 9, 2016

It has been 20 years since Dolly the sheep was successfully cloned in Scotland, but cloning mammals remains a challenge. A new study by researchers from the U.S. and France of gene expression in developing clones now shows ...

Blueprint for shape in ancient land plants

December 9, 2016

Scientists from the Universities of Bristol and Cambridge have unlocked the secrets of shape in the most ancient of land plants using time-lapse imaging, growth analysis and computer modelling.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.