Navigation Links
Parasites might spur evolution of strange amphibian breeding habits

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
University of Georgia

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:
(Date:11/12/2015)... , Nov. 11, 2015   Growing need ... analytical tools has been paving the way for ... determination of discrete analytes in clinical, agricultural, environmental, ... being predominantly used in medical applications, however, their ... sectors due to continuous emphasis on improving product ...
(Date:11/10/2015)... 2015 About signature verification ... to identify and verify the identity of an ... the secure and accurate method of authentication and ... individual because each individual,s signature is highly unique. ... dynamic signature of an individual is compared and ...
(Date:11/4/2015)... 4, 2015 --> ... published by Transparency Market Research "Home Security Solutions Market - ... 2015 - 2022", the global home security solutions market is expected ... 2022. The market is estimated to expand at a ... to 2022. Rising security needs among customers at homes, ...
Breaking Biology News(10 mins):
(Date:11/25/2015)... ... November 25, 2015 , ... ... were featured on AngelList early in their initial angel funding process. Now, they ... for individuals looking to make early stage investments in the microbiome space. ...
(Date:11/24/2015)... Nov. 24, 2015 Halozyme Therapeutics, Inc. (NASDAQ: HALO ... New York on Wednesday, December 2 at ... , president and CEO, will provide a corporate overview. ... at 1:00 p.m. ET/10:00 a.m. PT . ... will provide a corporate overview. --> th Annual ...
(Date:11/24/2015)... /PRNewswire/ - Aeterna Zentaris Inc. (NASDAQ:  AEZS) (TSX: AEZ) (the ... the Toronto Stock Exchange, confirms that as of the ... developments that would cause the recent movements in the ... --> About Aeterna Zentaris Inc. ... Aeterna Zentaris is a specialty biopharmaceutical company engaged in ...
(Date:11/24/2015)... IN (PRWEB) , ... November 24, 2015 , ... The ... newest Special Interest Group (SIG), MultiGP, also known as Multirotor Grand Prix, to represent ... the last few years. Many AMA members have embraced this type of racing and ...
Breaking Biology Technology: