Navigation Links
Parasites might spur evolution of strange amphibian breeding habits
Date:11/14/2007

Athens, Ga. Parasites can decimate amphibian populations, but one University of Georgia researcher believes they might also play a role in spurring the evolution of new and sometimes bizarre breeding strategies.

Brian Todd, a researcher at the UGA Odum School of Ecology Savannah River Ecology Lab, explains that most amphibians start their lives in water (tadpoles are a good example), and then make their way onto land as adults and return to the water to breed. But there are other breeding strategies as well. Take, for instance, the Darwins frog, the species that swallows its eggs and, a few weeks later, regurgitates its young. Or the marsupial frog, a species that carries its eggs on its back until they hatch. Several species lay eggs in small puddles on land or high up in trees where they hatch as miniature versions of adults, bypassing the larval stage entirely.

Researchers have hypothesized that natural selection favored these non-traditional breeding strategies as a way to avoid predatory fish or the risk of a breeding pond or stream drying up. In a review article published in the November issue of The American Naturalist, Todd argues that the diversity of reproductive strategies that amphibians employ might also be influenced by the benefits that come from avoiding viruses, fungi and other parasites.

Most parasites known to affect amphibians tend to be aquatic, so there are clearly benefits to using non-traditional breeding strategies, Todd said.

He points out that breeding in ponds or streams tends to concentrate amphibians in the same place at the same time, which increases the transmission of parasites. The process of metamorphosis decreases an amphibians immunity, which is another factor that benefits parasites at the expense of their amphibian hosts.

Todd said that the idea that parasites can influence reproductive strategies can be tested. A disease caused by a chytrid fungus is causing rapid declines in amphibian populations in Central and South America, and researchers can examine the populations over time to see if species with non-traditional breeding habits are less affected. Scientists could also compare the burden of parasites on traditional and non-traditional breeders.

Of course, there are benefits to breeding in the water most importantly that there is plenty of food. But Todd said that when the death rate from parasites or any other aquatic threats exceeds the benefits that come with rapid growth, natural selection begins to favor strategies that shorten or eliminate the aquatic life cycle phase altogether.

The role of parasites has been overlooked until now, Todd said. I want to highlight the idea that they might be important to evolution so that people can begin studying amphibians in a new light.


'/>"/>

Contact: Sam Fahmy
sfahmy@uga.edu
706-542-5361
University of Georgia
Source:Eurekalert

Related biology news :

1. Adaptation to parasites drive African fishes along different evolutionary paths
2. Social parasites of the smaller kind
3. Coral reef fish harbor an unexpectedly high biodiversity of parasites
4. Predators and parasites may increase evolutionary stability
5. Ultra-low-dose aspirin might decrease bleeding severity in portal hypertension
6. New magnetic separation technique might detect multiple pathogens at once
7. Curry-derived molecules might be too spicy for colorectal cancers
8. Evolution is driven by gene regulation
9. Clones on task serve greater good, evolutionary study shows
10. Uncertainty drives the evolution of cooperative breeding in birds
11. Structure of 450 million year old protein reveals evolutions steps
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/22/2016)... Ontario , PROVO and ... Newborn Screening Ontario (NSO), which operates the ... for molecular testing, and Tute Genomics and UNIConnect, ... management technology respectively, today announced the launch of a ... next-generation sequencing (NGS) testing panel. NSO ...
(Date:3/15/2016)... 15, 2016 --> ... Transparency Market Research "Digital Door Lock Systems Market - Global ... 2023," the global digital door lock systems market in terms ... and is forecast to grow at a CAGR of 31.8% ... and medium enterprises (MSMEs) across the world and high industrial ...
(Date:3/11/2016)... 2016 http://www.apimages.com ) - --> ... available at AP Images ( http://www.apimages.com ) - ... to produce the new refugee identity cards. DERMALOG will be unveiling ... in Hanover next week.   --> ... used to produce the new refugee identity cards. DERMALOG will be ...
Breaking Biology News(10 mins):
(Date:5/24/2016)... ... May 24, 2016 , ... Media Cybernetics, global ... Media Cybernetics corporate branding reflects a results-driven revitalization for a company with a ... re-branding components include a crisp, refreshed logo and a new web presence. , ...
(Date:5/23/2016)... LONDON , May 23, 2016 ... Boost Efficiency by 40% - Frontage Implement a Single ... Enforce Quality, Compliance and Traceability Within the Bioanalytical lab ... the United States and China ... deployed across its laboratory facilities. In addition to serving as the ...
(Date:5/20/2016)... ... ... Kablooe Design, a leading provider of product design and development services to medical ... “We have worked hard to build long-term relationships,” says President and CEO, Tom KraMer. ... serving their product design and development needs through the years.” , Kablooe has earned ...
(Date:5/19/2016)... , May 19, 2016 ... will fully recover given the relentless pressures in pricing ... sure in the investors circle though - numerous opportunities ... Ahead of today,s session, ActiveWallSt.com,s presents four names in ... ), Vitae Pharmaceuticals Inc. (NASDAQ: VTAE ), ...
Breaking Biology Technology: