Navigation Links
Superfast evolution in sea stars

How quickly can new species arise? In as little as 6,000 years, according to a study of Australian sea stars.

"That's unbelievably fast compared to most organisms," said Rick Grosberg, professor of evolution and ecology at UC Davis and coauthor on the paper published July 18 in the journal Proceedings of the Royal Society B.

Grosberg is interested in how new species arise in the ocean. On land, groups of plants and animals can be physically isolated by mountains or rivers and then diverge until they can no longer interbreed even if they meet again. But how does this isolation happen in the wide-open ocean?

Grosberg and colleagues studied two closely related "cushion stars," Cryptasperina pentagona and C. hystera, living on the Australian coast. The animals are identical in appearance but live in different regions: Hystera occurs on a few beaches and islands at the far southern end of the range of pentagona.

And their sex lives are very, very different. Pentagona has male and female individuals that release sperm and eggs into the water where they fertilize, grow into larvae and float around in the plankton for a few months before settling down and developing into adult sea stars.

Hystera are hermaphrodites that brood their young internally and give birth to miniature sea stars ready to grow to adulthood.

"It's as dramatic a difference in life history as in any group of organisms," Grosberg said.

The researchers looked at the diversity in DNA sequences from sea stars of both species and estimated the length of time since the species diverged.

The results show that the species separated about 6,000 to 22,000 years ago. That rules out some ways new species could evolve. For example, they clearly did not diverge slowly with genetic changes over a long period of time, but were isolated quickly.

Over the last 11,000 years, the boundary between cold and warm water in the Coral Sea has fluctuated north and south. A small population of the ancestral sea stars, perhaps even one individual, might have colonized a remote area at the southern end of the range then been isolated by one of these changes in ocean currents.

Contact: Andy Fell
University of California - Davis

Related biology news :

1. Scientists connect seawater chemistry with climate change and evolution
2. Tamarisk biocontrol efforts get evolutionary boost
3. Sandia seeks commercial partners for revolutionary SpinDx medical diagnostic tool
4. SDSCs CIPRES Science Gateway clarifies branches in evolutions tree of life
5. Revolutionary project will obtain entire genome sequences in fight against Alzheimers
6. Study provides first evidence of coevolution between invasive, native species
7. Mercury mineral evolution
8. Clues to nervous system evolution found in nerve-less sponge
9. Not a 1-way street: Evolution shapes environment of Connecticut lakes
10. Big-mouthed babies drove the evolution of giant island snakes
11. Maps of Miscanthus genome offer insight into grass evolution
Post Your Comments:
Related Image:
Superfast evolution in sea stars
(Date:3/24/2017)... March 24, 2017 The Controller General of Immigration ... Abdulla Algeen have received the prestigious international IAIR Award for ... Continue Reading ... ... Deputy Controller Abdulla Algeen (small picture on the right) have received the ...
(Date:3/23/2017)... 23, 2017 The report "Gesture Recognition and Touchless Sensing ... Geography - Global Forecast to 2022", published by MarketsandMarkets, the market is expected ... 29.63% between 2017 and 2022. Continue Reading ... ... ...
(Date:3/22/2017)... Lithuania , March 21, 2017   ... and object recognition technologies, today announced the release ... kit (SDK), which provides improved facial recognition using ... cameras on a single computer. The new version ... to improve accuracy, and it utilizes a Graphing ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... October 11, 2017 , ... ComplianceOnline’s Medical Device Summit ... 7th and 8th June 2018 in San Francisco, CA. The Summit brings together current ... several distinguished CEOs, board directors and government officials from around the world to address ...
(Date:10/11/2017)... ... October 11, 2017 , ... A ... pregnancy rates in frozen and fresh in vitro fertilization (IVF) transfer ... age to IVF success. , After comparing the results from the fresh and ...
(Date:10/10/2017)... ... October 10, 2017 , ... Dr. Bob Harman, founder and CEO ... Diego Rotary Club. The event entitled “Stem Cells and Their Regenerative ... attendees. Dr. Harman, DVM, MPVM was joined by two human doctors: Peter B. ...
(Date:10/9/2017)... , Oct. 9, 2017  BioTech Holdings ... mechanism by which its ProCell stem cell therapy ... limb ischemia.  The Company, demonstrated that treatment with ... of limbs saved as compared to standard bone ... molecule HGF resulted in reduction of therapeutic effect.  ...
Breaking Biology Technology: