Featured Research

from universities, journals, and other organizations

Evolutionary Change Leapfrogs Over Tadpoles

Date:
March 29, 2000
Source:
University Of Toronto
Summary:
Scientists at the University of Toronto have discovered a species of frog that skips the tadpole phase of development but still requires a thyroid to grow into fully formed adults.

Newly discovered species of frog bypasses the tadpole phase of development

University of Toronto scientists have recently discovered a species of frog that skips the tadpole phase of development but still requires a thyroid to grow into fully formed adults.

"We already knew that many frogs - mostly in tropical zones - bypass the tadpole stage and hatch from eggs as tiny versions of mature adults," says zoology professor Richard Elinson, who co-authored a paper with former doctoral student Elizabeth Callery. "But the question was 'How did they manage to do it?' Since a tadpole requires thyroid hormone to mature into an adult, was the hormone eliminated along with the tadpole phase? It had been assumed that this other species developed without a thyroid hormone but we've shown they still have a thyroid-dependent state."

Elinson calls this a classic case of evolutionary change in development. The theory is that this species, found in the tropics of Puerto Rico, evolved over millions of years to the point where it retained the hormone but lost its tadpole phase. In other words, he says, these frogs devised ways to evade dangerous living conditions in water containing predators - their mating occurs on land, fertilization happens in the body of the female and eggs are laid and hatched on land

The paper, titled Thyroid Hormone-Dependent Metamorphosis in a Direct Developing Frog, is featured in the March 14 issue of Proceedings of the National Academy of Sciences of the United States of America.

CONTACT:
Janet Wong
U of T Public Affairs
(416) 978-6974
jf.wong@utoronto.ca


Story Source:

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


Cite This Page:

University Of Toronto. "Evolutionary Change Leapfrogs Over Tadpoles." ScienceDaily. ScienceDaily, 29 March 2000. <www.sciencedaily.com/releases/2000/03/000328152247.htm>.
University Of Toronto. (2000, March 29). Evolutionary Change Leapfrogs Over Tadpoles. ScienceDaily. Retrieved September 14, 2014 from www.sciencedaily.com/releases/2000/03/000328152247.htm
University Of Toronto. "Evolutionary Change Leapfrogs Over Tadpoles." ScienceDaily. www.sciencedaily.com/releases/2000/03/000328152247.htm (accessed September 14, 2014).

Share This



More Plants & Animals News

Sunday, September 14, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Conservationists Face Uphill PR Battle With New Shark Rules

Conservationists Face Uphill PR Battle With New Shark Rules

Newsy (Sep. 14, 2014) — New conservation measures for shark fishing face an uphill PR battle in the fight to slow shark extinction. Video provided by Newsy
Powered by NewsLook.com
Shocker: Journalists Are Utterly Addicted To Coffee

Shocker: Journalists Are Utterly Addicted To Coffee

Newsy (Sep. 13, 2014) — A U.K. survey found that journalists consumed the most amount of coffee, but that's only the tip of the coffee-related statistics iceberg. Video provided by Newsy
Powered by NewsLook.com
'Magic Mushrooms' Could Help Smokers Quit

'Magic Mushrooms' Could Help Smokers Quit

Newsy (Sep. 11, 2014) — In a small study, researchers found that the majority of long-time smokers quit after taking psilocybin pills and undergoing therapy sessions. Video provided by Newsy
Powered by NewsLook.com
Spinosaurus Could Be First Semi-Aquatic Dinosaur

Spinosaurus Could Be First Semi-Aquatic Dinosaur

Newsy (Sep. 11, 2014) — New research has shown that the Spinosaurus, the largest carnivorous dinosaur, might have been just as well suited for life in the water as on land. Video provided by Newsy
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:
from the past week

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