Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Evolution At A Snail’s Pace

05.07.2004


Littorina saxatilis


Most visitors to the seaside are content to ride donkeys, eat ice cream, and build sandcastles. But, University of Leeds scientists have no time for sunbathing; they are witnessing the birth of a new species on the rocky shores of North Yorkshire.

Littorina saxatilis (right) is an unremarkable rough periwinkle – a small, grey-brown sea-snail which litters the coast by the million. But it has overcome its lack of charisma and grabbed the attention of scientists trying to unlock the secrets of evolution.

Biologist John Grahame (left) said: “This is an example of evolution in action, and we are increasingly certain that we are seeing one species become two.”



Evolution is a slow business at the best of times, and the process of speciation – the division of one species into two – takes millennia. The best scientists can hope to see is that two forms or ‘morphs’ within a species are moving apart, and becoming genetically distinct.

Down on beaches at Flamborough, Filey Brigg and Ravenscar, Dr Grahame and colleagues have shown that there are two distinct morphs of L. saxatilis inhabiting different parts of the beach, and the basis for the difference is genetic.

The really exciting development – the holy grail of speciation – is evidence that the morphs are becoming reproductively isolated and no longer freely interbreeding. Individual snails prefer to mate with others of the same morph, and when interbreeding does happen, the viability of the young is reduced.

“There are alternative explanations”, says Dr. Grahame, “and the process could easily be reversed. The point of no return, when we can truly say a new species has been born, will come when there is no interbreeding at all, and no gene flow between the morphs.”

The researchers are currently analysing genetic differences between morphs, and aim to relate the DNA sequence differences to physical characteristics.

Rough periwinkles are a favourite food of crabs, and it is likely that the two morphs use different strategies to stay off the menu. Crab ‘resistors’ are the thick shelled morph, found low on the beach where crabs are common, while thin shelled crab ‘avoiders’ are found higher up the shore.

This shows remarkable similarity to the evolutionary history of other periwinkles, such as the flat periwinkle species found in our waters, one of which is a crab avoider, the other a crab resistor. Dr. Grahame believes Littorina saxatillis is following slowly in their footsteps.

Vanessa Bridge | alfa
Further information:
http://www.leeds.ac.uk
http://reporter.leeds.ac.uk/500/s1.htm

More articles from Life Sciences:

nachricht Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University

nachricht Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>