BATON ROUGE -- By studying genetic data and fossil records of a common California snail, biologists from Louisiana State University and the University of California, San Diego have found that a change in a species' territory can bring on rapid morphological, or structural, evolutionary changes.
Assistant professor Michael Hellberg of LSU's Department of Biological Sciences and Kaustuv Roy and Deborah Balch of UCSD will have their findings published in the June 1 issue of Science, one of the world's premier scientific journals.
By studying different populations of Acanthinucela spirata, a marine gastropod found throughout the rocky coastal regions of California, the researchers discovered that past climatic changes altered the range of the species, which in turn, caused the species' shell shape to evolve. The scientists believe their findings can be applied to other animals, and that any change in an animal's environment or range, whether caused by climate changes, deforestation or any other means of relocation, could bring about the same results.
Fossil records show that the Earth's most recent series of ice ages pushed the Acanthinucela spirata species from northern California into the southern part of the state, where a number of genetic variations took place within the species. When conditions in the northern part of the state eventually warmed some 10,000 to 14,000 years ago some members of the snail species worked their way back in that direction, where they repopulated their old territory. The scientists discovered that the snails in the repopulated area to the north began to evolve differently from their southern counterparts, most noticeably in the shape of their shells. Snails with a thicker, shorter and broader shell emerged. This new shell shape had not previously existed.