Featured Research

from universities, journals, and other organizations

New Biodiversity Theory Suggests Rain Forest Conservation May Fall Short: Saving 'Edge' Habitats May Be Key To Saving Rain Forest Biodiversity

Date:
June 29, 1997
Source:
San Francisco State University
Summary:
In the June 20 issue of Science, a San Francisco State University researcher reports findings that challenge long-held views on how rain forest biodiversity is generated, and suggests the key to conservation may lie in protecting overlooked transitional zones along the forest periphery.

A team of scientists led by SFSU researcher Thomas B. Smith reports in the journal Science that ecotones, the transition areas between rain forests and savannas, may be integral to generating biodiversity in tropical rain forests.

Related Articles


Conserving these ecotones may be critical to preserving the processes that maintain diversity in rain forests, says Smith and his colleagues, Robert K. Wayne, UCLA; Derek Girman, SFSU Romberg Tiburon Center; and Michael Bruford, the Institute of Zoology, London.

"Ecotones are dynamic environments that have typically been overlooked," says Smith, an evolutionary biologist who specializes in the tropics. "The general belief is that if we preserve rain forests we're also preserving the processes that create biodiversity. But our findings suggest that the engines generating new species and increased biodiversity may lie in the unprotected ecotones at the forest periphery. "

Funded by the National Geographic Society, the National Environment Research Council of the UK, the World Wildlife Fund and the Royal Society, the 6-year-long study of West African rain forests and ecotones suggests a new paradigm for how biodiversity is generated.

Using molecular genetic techniques to examine the DNA of 12 populations of the little greenbul (Andropadus virens), a common West African bird species that inhabits both rain forests and adjacent ecotones, and by measuring their distinct physical characteristics, the team uncovered evidence linking ecotones with speciation.

"The findings are significant because they contrast with past theories of rain forest speciation which attribute the evolution to new species to geographic isolation, to the dynamics within the forest during glacial periods," says 41-year-old Smith. "Although much more work is needed, our results suggest that, instead, ecotones may be vital to the production and maintenance of biodiversity in tropical rain forests by creating new species through the process of natural selection."

In an accompanying Science news article, evolutionary biologist John Endler, who in 1977 was the first to suggest that natural selection may overcome gene flow, says Smith's work is "a major first step" in supporting the long-held hypothesis that natural selection not only shapes the physical appearance of all living organisms, but also may be important to the formation of new species.

From 1990 to 1996, the team compared birds from the forest and ecotone sites. Using mist nets to trap them, they drew blood for genetic analysis and measured five physical characteristics--weight, bill depth, and wing, tarsus and upper mandible length.

Smith found that although the ecotone populations were significantly different physically from their rain forest counterparts, there was considerable gene flow between them. Smith says this means that differences in natural selection may drive populations apart, despite gene flow.

"If new species are formed this way," reports Smith in Science, "they may move from their ecotone cradle to the forest and contribute to the biodiversity. If the work is confirmed by other studies, it may reinforce an idea that many biologists have suggested in the past, that rain forests are sinks for new species, rather than areas where new species are generated."

Rain forests contain 50 percent of the world's species, yet constitute only 7 percent of the earth's land mass. As forests shrink, says Smith, ecotones are some of the first habitats to disappear as a result of burning, wood gathering and grazing.

"If further research supports the role of ecotones as centers for speciation, they will need to be preserved," he says. "If we lose these habitats, we may be losing the processes that generate biodiversity."

Smith's team is continuing their work at 22 sites in West Africa. They plan to expand the study to include plants and mammals.

SFSU is a highly diverse community of 27,000 students and 3,500 faculty and staff members. It is the second largest of the nationally recognized 23-campus California State University System. Founded in 1899, the university is approaching its 100th year of service to San Francisco, the Bay Area, California and beyond.


Story Source:

The above story is based on materials provided by San Francisco State University. Note: Materials may be edited for content and length.


Cite This Page:

San Francisco State University. "New Biodiversity Theory Suggests Rain Forest Conservation May Fall Short: Saving 'Edge' Habitats May Be Key To Saving Rain Forest Biodiversity." ScienceDaily. ScienceDaily, 29 June 1997. <www.sciencedaily.com/releases/1997/06/970629233755.htm>.
San Francisco State University. (1997, June 29). New Biodiversity Theory Suggests Rain Forest Conservation May Fall Short: Saving 'Edge' Habitats May Be Key To Saving Rain Forest Biodiversity. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/1997/06/970629233755.htm
San Francisco State University. "New Biodiversity Theory Suggests Rain Forest Conservation May Fall Short: Saving 'Edge' Habitats May Be Key To Saving Rain Forest Biodiversity." ScienceDaily. www.sciencedaily.com/releases/1997/06/970629233755.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Earth & Climate News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Arctic Warming Twice As Fast As Rest Of Planet

Arctic Warming Twice As Fast As Rest Of Planet

Newsy (Dec. 18, 2014) The Arctic is warming twice as fast as the rest of the planet, thanks in part to something called feedback. Video provided by Newsy
Powered by NewsLook.com
Prenatal Exposure To Pollution Might Increase Autism Risk

Prenatal Exposure To Pollution Might Increase Autism Risk

Newsy (Dec. 18, 2014) Harvard researchers found children whose mothers were exposed to high pollution levels in the third trimester were twice as likely to develop autism. Video provided by Newsy
Powered by NewsLook.com
Ivory Trade Boom Swamps Law Efforts

Ivory Trade Boom Swamps Law Efforts

Reuters - Business Video Online (Dec. 17, 2014) Demand for ivory has claimed the lives of tens of thousands of African elephants and now a conservation report says the illegal trade is overwhelming efforts to enforce the law. Amy Pollock reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins