Navigation Links
Why are some groups of animals so diverse?
Date:9/19/2007

A new study of finger-sized Australian lizards sheds light on one of the most striking yet largely unexplained patterns in nature: why is it that some groups of animals have evolved into hundreds, even thousands of species, while other groups include only a few?

The study takes a look at Australias most diverse group of vertebratesmore than 252 species of lizards called skinks. Researchers at the Cornell Lab of Ornithology have found evidence that the drying up of Australia over the past 20 million years triggered this explosive diversification. The results were published in the September 19 online edition of the Proceedings of the Royal Society B.

Lead author Dan Rabosky, a Cornell graduate student, spent many months in the remote Australian outback, trapping skinks as they skittered from one prickly clump of grass to another. By documenting where the various skink species occur and using their DNA to define their evolutionary tree, he found that the groups with the most species are the ones that live in the driest parts of Australia. Theres something about colonizing the desert that caused these skinks to diversify at an incredibly high rate, says Rabosky.

An unusual finding of this study is that these skinks upend the usual pattern of species diversity found in other parts of the world. We typically think of lush tropical rainforests as being the worlds major centers of diversity, says coauthor Irby Lovette, director of the Cornell Lab of Ornithologys Fuller Evolutionary Biology Program. With the skinks, just the opposite has happened: the rainforest skinks in Australia have much lower diversity, and a lot of the evolutionary action in this system is taking place in the deserts.

Over the last 20 million years, most of Australia changed from humid and tropical to bone-dry desert. Living in the desert is stressful for animals that are adapted for wetter habitats, says Rabosky. But somewhere in the distant past, a few skinks developed the ability to survive in their increasingly arid world. It is the descendents of these few early desert colonists that evolved into amazingly large numbers of skink species.

Australian skinks are really fascinating, Rabosky says. Two groups in particular have gone evolutionarily crazy, each splitting into as many as 100 different species. In contrast to skinks on other continents, and even some other groups in Australia, the diversity of these particular groups has really exploded.

Raboskys study included skinks with spots, skinks with stripes, skinks with four legs, or twoor none. Rabosky says there are at least 252 species of these lizards living Down Under, and probably many more that remain to be discovered.

The evolution of these skinks mirrors that of many groups of organismsfrom grasses, to beetles, to humans and our relativesin which some groups have spectacular diversity and others a paucity of species. For me as a scientist, says Rabosky, one of the great things about skinks is that there are just so darn many species, making the patterns in their diversity really clear.


'/>"/>

Contact: Miyoko Chu
mcc37@cornell.edu
607-254-2451
Cornell University News Service
Source:Eurekalert

Related medicine news :

1. No link between blood groups and prostate cancer
2. Religious groups overcome objections to cervical cancer vaccines
3. Yogic Moments: Age Old Yoga, Benefits All Age Groups
4. Plastic Surgery Is Primetime among Ethnic Groups
5. Study Finds Online Support Groups Emotionally Benefit Women Suffering From
6. Specialist Services Can Help Ethnic Groups To Tackle Alcohol Misuse
7. Distinct Support Services Needed, To Resurrect Ethnic Groups from Alcohol Abuse
8. NGOs and Various Groups Come Together To Address the Issues on AIDS
9. U.S: Prize for the best hearing category (ethnic groups) goes to…. Non-Hispanic Blacks
10. Anti-Obesity Groups Criticize Response of Medical Professionals
11. Hospitals Appeal to Citizen Groups to Rush Doctors, Paramedicals
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:4/28/2016)... D.C. (PRWEB) , ... April 28, 2016 , ... USA Medical Card reminds us that ... Prevention (CDC), a stroke is the fourth leading cause of death in the United States; ... with almost a quarter of them in individuals under 65 years old. A stroke ...
(Date:4/28/2016)... ... 2016 , ... Point Source Audio® (PSA) , an ... today that the US Patent Office has approved its patent submission that covers ... design creates a lightweight and modular audio headset that has been said to ...
(Date:4/28/2016)... Cary, NC (PRWEB) , ... April 28, 2016 ... ... to announce it has partnered with Community Oncology Pharmacy Association (COPA) to develop ... elevate the practice of oncology by introducing an accreditation distinction. ACHC provides a ...
(Date:4/28/2016)... , ... April 28, 2016 , ... ... Pharmacy Discount Cards in the mail from USA Medical Prescription Assistance Program. They ... , Each mailed package will include a ready-to-use, state-themed card and, ...
(Date:4/28/2016)... ... April 28, 2016 , ... For the 10,000 Americans who turn ... an important part of overall well-being: mental health. Now, a new book—Staying Sharp For ... aging and “cognitive vitality,” which can include everything from honing your memory and managing ...
Breaking Medicine News(10 mins):
(Date:4/28/2016)... -- Research and Markets has announced the ... 2016-2020" report to their offering.      ... global plastic surgery products market is expected to grow ... , ,The growing adoption of laser in aesthetics is ... market. Lasers are used to treat a broad range ...
(Date:4/28/2016)... 28, 2016  The blood testing market in ... to Kalorama Information and The Freedonia Group in a ... acid testing.  The healthcare research firm said that ... blood collection stations and in improving testing at the ... report, Blood Testing Market in China ...
(Date:4/28/2016)... April 28, 2016 Dr. Vivek ... and Ste phen Schmidt ... a leading provider of cloud-based software solutions for life sciences, today ... to bring a wealth of insight to a growing business.  This ... George Phillips joined ArisGlobal in the position ...
Breaking Medicine Technology: