Researchers discover unexpected patterns in evolution of frog life cycles

Sep 10, 2012
Credit: Stony Brook University

All tadpoles grow into frogs, but not all frogs start out as tadpoles, reveals a new study on 720 species of frogs to be published in the journal Evolution.

The study, "Phylogenetic analyses reveal unexpected patterns in the evolution of reproductive modes in frogs," led by John J. Wiens, an Associate Professor in the Department of at Stony Brook University, and colleagues Ivan Gomez-Mestra from the Doñana Biological Station in Seville, Spain, and R. Alexander Pyron from George Washington University, uncovers the surprising evolution of in frogs.

Roughly half of all have a life cycle that starts with eggs laid in water, which hatch into aquatic , and then go through metamorphosis and become adult frogs. The other half, according to the authors, "includes an incredible cycles, including in which eggs are placed on leaves, in nests made of foam, and even in the throat, stomach, or back of the female frog. There are also hundreds of species with no tadpole stage at all, a reproductive mode called direct development."

For decades, it has been assumed that the typical mode (with eggs and tadpoles placed in water) gave rise to direct development through a series of gradual intermediate steps involving eggs laid in various places outside water. "However, the results show that in many cases, species with eggs and tadpoles placed in water seem to give rise directly to species with direct development, without going through the many seemingly intermediate steps that were previously thought to be necessary," Dr. Wiens said.

"The results also suggests that there many potential benefits for species that have retained aquatic eggs and tadpoles, such as allowing females to have more offspring and to colonize regions with cooler and drier climates. These advantages may explain why the typical frog life cycle has been maintained for more than 220 million years among thousands of species," said Professor Wiens.

Explore further: Rock-paper-scissors model helps researchers demonstrate benefits of high mutation rates

add to favorites email to friend print save as pdf

Related Stories

Frogs with disease-resistance genes may escape extinction

Jul 16, 2008

As frog populations die off around the world, researchers have identified certain genes that can help the amphibians develop resistance to harmful bacteria and disease. The discovery may provide new strategies to protect ...

Eradicating cane toads with 'their own medicine'

Nov 14, 2011

Sydney University biologists have discovered cane toad tadpoles (Bufo marinus) communicate using chemicals excreted into the water, a finding that may help to impede the Cane Toad invasion of the Kimberley.

New boulder frog discovered

Oct 07, 2011

(PhysOrg.com) -- Scientists have discovered two new species of boulder-dwelling frogs, hidden in remote areas of rainforest in north-east Queensland.

Inventions of evolution: What gives frogs a face

Jan 13, 2011

Zoologists of the University Jena (Germany) analysed the central factor for the development of the morphologically distinctive features of the tadpoles. "We were able to show that the 'FOXN3' most of all influences ...

Recommended for you

Plants with dormant seeds give rise to more species

Apr 18, 2014

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Researchers successfully clone adult human stem cells

Apr 18, 2014

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

KalinForScience
not rated yet Sep 10, 2012
not all tadpoles grow into frogs.., some grow into salamanders, newts, etc... :)

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Biologists help solve fungi mysteries

(Phys.org) —A new genetic analysis revealing the previously unknown biodiversity and distribution of thousands of fungi in North America might also reveal a previously underappreciated contributor to climate ...

NASA's space station Robonaut finally getting legs

Robonaut, the first out-of-this-world humanoid, is finally getting its space legs. For three years, Robonaut has had to manage from the waist up. This new pair of legs means the experimental robot—now stuck ...

Ex-Apple chief plans mobile phone for India

Former Apple chief executive John Sculley, whose marketing skills helped bring the personal computer to desktops worldwide, says he plans to launch a mobile phone in India to exploit its still largely untapped ...

Filipino tests negative for Middle East virus

A Filipino nurse who tested positive for the Middle East virus has been found free of infection in a subsequent examination after he returned home, Philippine health officials said Saturday.

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.