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 August 21, 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 August 21, 2014).

Share This




More Plants & Animals News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Possible Ebola Patient in Isolation at California Hospital

Possible Ebola Patient in Isolation at California Hospital

Reuters - US Online Video (Aug. 20, 2014) — A patient who may have been exposed to the Ebola virus is in isolation at the Kaiser Permanente South Sacramento Medical Center. Linda So reports. Video provided by Reuters
Powered by NewsLook.com
Flower Power! Dandelions Make Car Tires?

Flower Power! Dandelions Make Car Tires?

Reuters - Business Video Online (Aug. 20, 2014) — Forget rolling on rubber, could car drivers soon be traveling on tires made from dandelions? Teams of scientists are racing to breed a type of the yellow flower whose taproot has a milky fluid with tire-grade rubber particles in it. As Joanna Partridge reports, global tire makers are investing millions in research into a new tire source. Video provided by Reuters
Powered by NewsLook.com
Unsustainable Elephant Poaching Killed 100K In 3 Years

Unsustainable Elephant Poaching Killed 100K In 3 Years

Newsy (Aug. 20, 2014) — Poachers have killed 100,000 elephants between 2010 and 2012, as the booming ivory trade takes its toll on the animals in Africa. Video provided by Newsy
Powered by NewsLook.com
Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Newsy (Aug. 19, 2014) — Scientists have developed a new device that mimics the way octopuses blend in with their surroundings to hide from dangerous predators. 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