Post by Karstscience on Feb 23, 2006 18:43:54 GMT -5
BYU study uses genetics to show a species less endangered than previously thought
Although the ability to compare the DNA sequences of various types of animals has often resulted in the discovery of new, very rare species that require government protection to survive, a new genetic analysis by Brigham Young University researchers came to the opposite conclusion about cave crayfish in the southeastern United States.
A BYU study determined this type of crayfish, found only in caves and previously thought to be endangered, enjoys a healthy population.
"I certainly expected these things to be very isolated, to have small population sizes, and to be very endangered," said Keith Crandall, professor of molecular and integrative biology. "But the data simply didn't support this conclusion."
The study is published in the new issue of "Molecular Ecology," with Crandall's Ph.D. candidate Jennifer Buhay as lead author.
Because the cave crayfish make their homes in underground aquifers that are obviously very difficult for humans to access, previous population estimates were based on physical counts that may not have been comprehensive.
"The provocative conclusion of the paper is that the cave species of crayfish, which were all considered highly endangered, in part because of the assumption of extremely low population sizes, actually have much larger effective population sizes as measured through population genetics," Crandall explained.
By comparing their genetic analysis of the cave species with that of crayfish in streams and rivers, Buhay and Crandall found that the cave dwellers actually have more robust populations than their surface-dwelling cousins, which had been considered stable.
"The implications of this type of research are very broad -- from how folks like The Nature Conservancy decide how and what to protect to the how the Department of Interior goes about defining species under the Endangered Species Act," said Crandall. "This type of analysis gives you reliable answers despite your intuition or emotion."
He was one of two outside consultants invited to a meeting hosted last spring by Julie MacDonald, Deputy Assistant Secretary, U.S. Department of the Interior, on using genetics in conservation.
In addition to revealing the existence of a new species of cave crayfish, the study also had the improbable result of discovering new features of cave hydrology. Because crayfish collected from different caves shared molecular similarities, the researchers established the caves must be connected somehow to allow interbreeding.
Although the ability to compare the DNA sequences of various types of animals has often resulted in the discovery of new, very rare species that require government protection to survive, a new genetic analysis by Brigham Young University researchers came to the opposite conclusion about cave crayfish in the southeastern United States.
A BYU study determined this type of crayfish, found only in caves and previously thought to be endangered, enjoys a healthy population.
"I certainly expected these things to be very isolated, to have small population sizes, and to be very endangered," said Keith Crandall, professor of molecular and integrative biology. "But the data simply didn't support this conclusion."
The study is published in the new issue of "Molecular Ecology," with Crandall's Ph.D. candidate Jennifer Buhay as lead author.
Because the cave crayfish make their homes in underground aquifers that are obviously very difficult for humans to access, previous population estimates were based on physical counts that may not have been comprehensive.
"The provocative conclusion of the paper is that the cave species of crayfish, which were all considered highly endangered, in part because of the assumption of extremely low population sizes, actually have much larger effective population sizes as measured through population genetics," Crandall explained.
By comparing their genetic analysis of the cave species with that of crayfish in streams and rivers, Buhay and Crandall found that the cave dwellers actually have more robust populations than their surface-dwelling cousins, which had been considered stable.
"The implications of this type of research are very broad -- from how folks like The Nature Conservancy decide how and what to protect to the how the Department of Interior goes about defining species under the Endangered Species Act," said Crandall. "This type of analysis gives you reliable answers despite your intuition or emotion."
He was one of two outside consultants invited to a meeting hosted last spring by Julie MacDonald, Deputy Assistant Secretary, U.S. Department of the Interior, on using genetics in conservation.
In addition to revealing the existence of a new species of cave crayfish, the study also had the improbable result of discovering new features of cave hydrology. Because crayfish collected from different caves shared molecular similarities, the researchers established the caves must be connected somehow to allow interbreeding.