Gainesville, FL --- A paper appearing in today's journal Science offers new evidence that scientists are close to pinning down the evolutionary road map for the most diverse and largest subgroup of mammals, a feat that may resolve a longstanding scientific debate and shed light on the newly completed human genome.
The paper, prepared by a team of University of Florida faculty members, graduate and undergraduate students, follows publication in February of two related papers in the journal Nature. Although authors in each case used different methods, their conclusions are remarkably similar, pointing to growing consensus on a topic that has long divided scientists.
"Five years ago, nobody thought this would happen," said Michael Miyamoto, UF professor and associate chairman of zoology and an author of the Science paper. "We have come from great pessimism to great hope that weve nearly resolved placental mammal history."
Scientists have been trying to sort out how animals are related to one another since Carolus Linnaeus, an 18th-century botanist and explorer, first came up with the basic principles for dividing them into species and larger groups. Evolutionary biologists are interested not only in how to group animals, but also in which ones evolved first and how their traits are carried on or modified in animals that evolved later.
The traditional method is to compare the physical features of animals with other animals or fossilized specimens. Shared features -- anything from an animals appearance to the shape and placement of its teeth -- form the basis for placing the animal within a species or the successively more inclusive groups of genera, families and orders.
Soon after the description of DNA as the double helix in the 1950s, scientists started using a completely new method to sort out such relationships: molecular genetics. This "molecular method" is similar to the traditional "morphological method" in that it makes decisions based on
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Contact: Michael Miyamoto
miyamoto@zoo.ufl.edu
352-392-3275
University of Florida
1-Mar-2001