Navigation Links
Research shows that environmental factors limit species diversity
Date:12/20/2010

It's long been accepted by biologists that environmental factors cause the diversityor numberof species to increase before eventually leveling off. Some recent work, however, has suggested that species diversity continues instead of entering into a state of equilibrium. But new research on lizards in the Caribbean not only supports the original theory that finite space, limited food supplies, and competition for resources all work together to achieve equilibrium; it builds on the theory by extending it over a much longer timespan.

The research was done by Daniel Rabosky of the University of California, Berkeley and Richard Glor of the University of Rochester who studied patterns of species accumulation of lizards over millions of years on the four Caribbean islands of Puerto Rico, Jamaica, Hispaniola, and Cuba. Their paper is being published December 21 in the journal, Proceedings of the National Academy of Sciences.

Glor and Rabosky focused on species diversitythe number of distinct species of lizardsnot the number of individual lizards.

"Geographic size correlates to diversity," said Glor. "In general, the larger the area, the greater the number of species that can be supported. For example, there are 60 species of Anolis lizards on Cuba, but far fewer species on the much smaller islands of Jamaica and Puerto Rico." There are only 6 species on Jamaica and 10 on Puerto Rico.

Ecologists Robert MacArthur of Princeton University and E.O. Wilson of Harvard University established the theory of island biogeography in the 1960s to explain the diversity and richness of species in restricted habitats, as well as the limits on the growth in number of species. Glor said the MacArthur-Wilson theory was developed for ecological time-scales, which encompass thousands of years, while his work with Rabosky extends the concepts over a million years. "MacArthur and Wilson recognized the macroevolutionary implications of their work," explained Glor, "but focused on ecological time-scales for simplicity."

Historically, biologists needed fossil records to study patterns of species diversification of lizards on the Caribbean islands. But advances in molecular methodology allowed Glor and Rabosky to use DNA sequences to reconstruct evolutionary trees that show the relationships between species.

The two scientists found that species diversification of lizards on the four islands reached a plateau millions of years ago and has essentially come to an end.

Glor said the extent and quality of the data used in the research allowed him and Rabosky to show that species diversification of lizards on the islands was not continuing and had indeed entered a state of equilibrium.

"When we look at other islands and continents that vary in species richness," said Glor, "we can't just consider rates of accumulation; we need to look at the plateau points."

Glor emphasizes that a state of equilibrium does not mean that the evolution of a species comes to an end. Lizards will continue to adapt to changes in their environment, but they are not expected to develop in a way that increases the number of species within a habitat.

Glor believes his work with Rabosky represents the "final word" on the importance of limits on species diversity over the rate of speciation when explaining the species-area relationship in anole lizards.


'/>"/>

Contact: Peter Iglinski
585-273-4726
University of Rochester
Source:Eurekalert

Related biology news :

1. The orange in your stocking: researchers squeezing out maximum health benefits
2. Damon Runyon Cancer Research Foundation awards breakthrough scientists
3. Reducing emissions from shipping: Commissions Joint Research Centre sets out some options
4. Researchers discover human immune system has emergency backup plan
5. New research shows virus previously linked to chronic fatigue syndrome is a lab contaminant
6. German federal government bolsters neutron research in Garching
7. K-State research looks at pathogenic attacks on host plants
8. Scripps Research scientists show prions mutate and adapt to host environment
9. Researcher finds proximity to freeway associated with autism
10. Breakthrough in worm research has implications for human disease studies
11. Autism Speaks awards 21 new research grants funding
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/19/2016)... UAE, April 20, 2016 The ... as a compact web-based "all-in-one" system solution for all ... fingerprint reader or the door interface with integration authorization ... access control systems. The minimal dimensions of the access ... into the building installations offer considerable freedom of design ...
(Date:4/14/2016)... 14, 2016 BioCatch ™, ... today announced the appointment of Eyal Goldwerger ... Goldwerger,s leadership appointment comes at a time ... the deployment of its platform at several of the ... which discerns unique cognitive and physiological factors, is a ...
(Date:3/31/2016)... March 31, 2016  Genomics firm Nabsys has completed ... Barrett Bready , M.D., who returned to the ... original technical leadership team, including Chief Technology Officer, ... Development, Steve Nurnberg and Vice President of Software and ... company. Dr. Bready served as CEO of ...
Breaking Biology News(10 mins):
(Date:6/23/2016)... , June 23, 2016 Apellis ... Phase 1 clinical trials of its complement C3 ... single and multiple ascending dose studies designed to ... (PD) of subcutaneous injection in healthy adult volunteers. ... (SC) either as a single dose (ranging from ...
(Date:6/23/2016)... ... June 23, 2016 , ... Regulatory Compliance ... consulting, provides a free webinar on Performing Quality Investigations: Getting to ... 12pm CT at no charge. , Incomplete investigations are still a major concern ...
(Date:6/22/2016)... 22, 2016 Research and Markets has announced ... report to their offering. ... from $29.3 billion in 2013. The market is expected to grow ... 2015 to 2020, increasing from $50.6 billion in 2015 to $96.6 ... during the forecast period (2015 to 2020) are discussed. As well, ...
(Date:6/22/2016)... Washington, USA (PRWEB) , ... June 21, 2016 , ... ... and without cutting into the tissue — promise to enable both compact, wearable devices ... and from even deeper under the skin. , Recent work and visionary future directions ...
Breaking Biology Technology: