Many scientists are concerned that plant and animal species may face extinction due to global warming, but biologists at Washington University in St. Louis are trying to predict exactly what will happen to them. Which species will migrate? Which evolve? Which change their behavior? Which become extinct?
Rather than peer into the future, they are looking backward, exploring how species alive today survived global warming at the end of the Pleistocene and asking whether their responses provide any guidance for us today.
For his dissertation Brad Oberle, a doctoral candidate in biology in Arts & Sciences at Washington University in St. Louis, delved into the post-Pleistocene history of three species of shootingstars (Dodecatheon).
Dodecatheon is a genus of flowering plant in the Primrose family, the petals of whose nodding flowers flex upward, giving the flowers the appearance of a star falling to earth, trailing flames behind it.
Two of the species, the jeweled shootingstar (D. amethystinum), and French's shootingstar (D. frenchii), are rare and grow only in cliff habitats.
Are the rare species glacial relicts, species adapted to the cool wet conditions during the Pleistocene that gradually retreated to smaller and smaller refuges as the climate warmed? Or were they ecotypes, local variants of a widespread species, Mead's shootingstar (D. meadia), that had adapted to cliff microclimates but were genetically similar to Mead's shootingstar.
"As is typical of science," says Barbara A. Schaal, PhD, the Mary-Dell Chilton Distinguished Professor of biology in Arts & Sciences, Oberle's dissertation advisor, and his co-author, "the result was mixed. One species is probably a relict species, and the other is probably an ecotype. Some species responded to warming by migrating but other populations apparently adapted in place."
The article was published in the April 5th issue of the Proce
|Contact: Diana Lutz|
Washington University in St. Louis