Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Drilled shells show extinction’s lasting effects

27.12.2004


Give a marine snail an easy life, and it will take its time drilling into a clam. Put it under competitive stress, and it will look for a faster route. Those changes, scarred into fossils, show that an unknown catastrophe nearly two million years ago changed the competitive balance in the Western Atlantic and the ecosystem has yet to fully recover, according to research published this week in the journal Science.



In the seagrass meadows of the Gulf of Mexico, Chicoreus and Phyllonotus marine snails feed on Chione clams by slowly drilling a hole through the shell wall. That process can take a week, while the snails risk losing their prey to another snail or being attacked themselves by fish, crabs or other predators.

High levels of competition should favor faster feeding, said Geerat Vermeij, professor of geology at UC Davis and an author on the paper. The snails can get a quicker meal by drilling through the thinnest part at the shell’s edge -- but risk getting their feeding proboscis nipped off by the closing shell.


The pattern of drill holes in fossil shells can give insight into what life in the ocean was like millions of years ago and how it compares to today.

In the laboratory, Gregory Dietl, a postdoctoral researcher at the University of North Carolina who is now at Yale University, UC Davis graduate student Gregory Herbert (now at the University of South Florida) and Vermeij found that when modern-day snails had to compete for food with other snails, they began edge-drilling their prey. When they were separated, they went back to slow wall drilling.

"They have the same gene pool, but you can elicit different behaviors depending on the competitive environment," Vermeij said.

A severe but regional extinction event at the end of the Pliocene Epoch 1.7 million years ago seems to have tilted the balance from high competition to low competition, according to the researchers. At that time, up to 70 percent of marine species in the Western Atlantic Ocean disappeared, with some parts of the world affected to a lesser extent and others unscathed.

The researchers looked at thousands of fossil clam shells from before and after the extinction and compared them with modern shells. Edge-drilled shells are abundant up to 1.7 million years ago, and then disappear entirely. None of the modern shells they looked at show edge-drilled holes.

The results show that competition intensity has not returned to pre-extinction levels even though a long time has passed since the event, Vermeij said.

The cause of the Pliocene extinction remains unknown. The work is published in the Dec. 24 issue of Science.

Andy Fell | EurekAlert!
Further information:
http://www.ucdavis.edu

More articles from Ecology, The Environment and Conservation:

nachricht International network connects experimental research in European waters
21.03.2017 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

nachricht World Water Day 2017: It doesn’t Always Have to Be Drinking Water – Using Wastewater as a Resource
17.03.2017 | ISOE - Institut für sozial-ökologische Forschung

All articles from Ecology, The Environment and Conservation >>>

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

Pulverizing electronic waste is green, clean -- and cold

22.03.2017 | Materials Sciences

Astronomers hazard a ride in a 'drifting carousel' to understand pulsating stars

22.03.2017 | Physics and Astronomy

New gel-like coating beefs up the performance of lithium-sulfur batteries

22.03.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>