Navigation Links
Sky islands: metaphor or misnomer?
Date:8/13/2008

The term "sky islands" sounds intriguing, but it may be more lyrical than useful when discussing mammal distributions, according to new research from Eric Waltari of the Sackler Institute of Comparative Genomics at the American Museum of Natural History and Robert Guralnick from the University of Colorado at Boulder. The team used an emerging technique, ecological niche modeling, to show that the populations of small mammals living on mountaintops in the Great Basinon islands in the skyare not as isolated as previously thought.

"Niche modeling is a quick and straightforward approach to addressing problems that molecular data will eventually solve," says Waltari. "Are the animals on 'sky islands' isolated?"

The answer is no. "Sky islands" is a biogeographical term that was coined to describe the habitats of species living high on mountaintops, habitats thought to be solidly isolated. In the new paper published in the early online version of the , Waltari and Guralnick test the concept of geographic isolation on thirteen species of jackrabbits, shrews, ground squirrels, and other small mammals. The species chosen have detailed location records that were mapped with current and past climate data, such as temperature and rainfall, to "backcast" the distribution of each species at the height of the last ice age 21,000 years ago. The predictions of the model are calibrated with known fossil records. Backcasting allows researchers to test whether species had wider ranges or different distributions in the past; the current study, for example, found that most of the species (12 of 13) lived at lower elevations 21,000 years ago and that the average distribution of each species was larger than it is now.

Determining the area that species inhabited in the past helps researchers understand current population distribution within the western U.S.'s Great Basin and potential linkages between "sky islands," links that can be tested with molecular research now that the models have pinpointed which populations of which species are most likely to intermingle. In this study, Waltari and Guralnick also found that not all species were widespread across the basin 21,000 years ago. For example, one prediction is that Belding's Ground Squirrels inhabited only the western portion of the Great Basin at the last full glacial period. Belding's ground squirrels currently live at higher elevations of the same portion of Great Basin, but some valley connections also appear to currently be suitable habitat according to the model. Many of the species (9 of 13) had suitable habitat below the "sky islands" that may link different populations.

"Connectivity is an important aspect of conservation biology," says Waltari. "Also, testing niche models in the present and past is the first step in making predictions about where species will move in the future given global warming scenarios."


'/>"/>

Contact: Kristin Phillips
kphillips@amnh.org
212-496-3419
American Museum of Natural History
Source:Eurekalert

Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/22/2016)... , January 22, 2016 ... the addition of the  "Global Behavioral ... offering. --> http://www.researchandmarkets.com/research/4lmf2s/global_behavioral ) ... "Global Behavioral Biometric Market 2016-2020"  report ... Research and Markets ( http://www.researchandmarkets.com/research/4lmf2s/global_behavioral ) has ...
(Date:1/20/2016)... Jan. 20, 2016 A market that just ... benefit from the explosion in genomics knowledge. Learn all ... Research. A range of dynamic trends are pushing market ... personalized medicine - pharmacogenomics - pathogen evolution - next ... markets - greater understanding of the role of genetic ...
(Date:1/18/2016)... Calif. , Jan. 18, 2016  Extenua ... software that simplifies the use and access of ... and go-to-market partnership with American Cyber.  ... brings extensive experience leading transformational C4ISR and Cyber ... and integrating the latest proven technology solutions," said ...
Breaking Biology News(10 mins):
(Date:2/11/2016)... (PRWEB) , ... February 11, 2016 , ... ... regenerative medicine, has announced a new agreement with Bankok,Thailand-based Global Stem Cells Network ... and phsyicians in 15 Latin American countries, including Mexico, Costa Rica, Dominican Republic, ...
(Date:2/10/2016)... -- The Maryland House of Delegates and House Speaker ... Maryland School of Medicine Dean E. Albert Reece ... System President and CEO Robert Chrencik , MBA, ... given to the public by the leader of the ... and Mr. Chrencik for their contributions to our statewide ...
(Date:2/10/2016)... 2016  IsoRay, Inc. (NYSE MKT: ISR), a medical ... radioisotope applications for the treatment of prostate, brain, lung, ... financial results for the second quarter and six months ... --> --> Revenue ... 2016, which ended December 31, 2015, a 12% increase ...
(Date:2/10/2016)... , ... February 10, 2016 , ... ... the International Society of Pharmaceutical Engineering (ISPE) Rocky Mountain Chapter 21st Annual Vendor ... expecting to fill more than 100 tables for its annual event, which will ...
Breaking Biology Technology: