Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Ocean seep mollusks may share evolutionary history with other deep-sea creatures

11.09.2006
Seeps were a shelter from extinctions and abrupt sea changes, Science researchers say

The unusual mollusks of oceanic cold seeps--strange clams, mussels and sea snails that thrive in the sulfur and methane-rich environments--are on average older than the marine mollusk community as a whole, according to a new report in the 8 September issue of the journal Science, published by AAAS, the nonprofit science society.

On average, the first appearance of cold seep mollusk genera in the geological record is a full epoch earlier than that of marine mollusks in general, according to Steffen Kiel and Crispin Little of the University of Leeds.

These findings indicate that the long evolutionary history of the seep mollusks is more similar to that of other deep-sea animals than to some of their mollusk contemporaries from other parts of the oceans.

... mehr zu:
»Little »Seep

Cold seeps may have been--and continue to be--safe harbors for the mollusks, protecting them from mass extinctions and possible abrupt oxygen changes in the seas, the researchers found. However, many deep-sea species outside of the cold seeps have also managed to ride out these changes.

"The shallow water environment is much more challenging, subject to changes in sea levels, extinction events, pollution, sediment runoff--all sorts of factors which don't affect animals in the deep sea," Little explained.

This makes it difficult to tell whether seep mollusks owe their long evolutionary history to their unique home environment or to their status as deep-sea creatures, he noted.

Cold seeps are places where fluids rich in hydrogen sulfide and methane leak up through the ocean floor, creating a unique chemical environment where hardy bacteria process the sulfide and methane. Seep fluids are about the same temperature as surrounding waters, but similar chemically challenging environments exist at hydrothermal vents, fissures in the ocean floor where water is superheated by magma lurking just below the crust.

Although seep and vent fluids are a poisonous brew for most species, animals such as giant tube worms and the mollusks studied by Kiel and Little thrive with the help of the symbiotic bacteria. "If you can become adapted to living at these sites, you can make a very good living indeed," Little said.

The origins and age of seep citizens such as the mollusks has been debated for some time by scientists using both fossil and genetic evidence. Kiel and Little decided to examine the fossil record for modern seep mollusks to see how their history compared to that of the overall marine mollusk population.

By sorting 29 mollusk genera into the geological time periods when they first appeared, the researchers found that seep mollusk genera, on average, appeared during the Eocene epoch about 55 to 34 million years ago. By contrast, the average age of first appearances for all marine mollusks occurred in the Oligocene epoch, about 34 to 24 million years ago.

Following the fortunes of seep mollusks through time, Kiel and Little also found little evidence that mass extinction events or periods of low oxygen dealt significant blows to the seep communities. Seeps may have been good shelters during these events because "they were driven by a constant source of geothermal energy," Little said.

The Eocene age calculated by the Science researchers casts some doubt on another mystery involving seep animals: what is their relationship to whale falls? Whale falls, the slowly decaying remains of large whales sunk to the ocean's depths, harbor yet another unique chemical community similar to that in vents and seeps.

Some researchers suggest that whale falls were evolutionary "stepping stones," creating new environments for seep animals to evolve into a plethora of new species. But Kiel and Little's work shows that more than three-quarters of seep mollusk genera had already appeared by the time oceangoing whales would have filled the seas.

Whale falls "are not instrumental in the evolution" of seep mollusks, but the falls "may have allowed them to expand into new sites," Little explained.

"Cold seep mollusks are older than the general marine mollusk fauna" by Steffen Kiel and Crispin T.S. Littleat the University of Leeds.

Natasha Pinol | EurekAlert!
Weitere Informationen:
http://www.aaas.org

Weitere Berichte zu: Little Seep

Weitere Nachrichten aus der Kategorie Ökologie Umwelt- Naturschutz:

nachricht Intelligentes Wassermanagement für Indiens Städte
24.11.2017 | Fraunhofer-Institut für Grenzflächen- und Bioverfahrenstechnik IGB

nachricht Antarktisches Meereis: mehr Schutz als Vorratskammer für Krilllarven
22.11.2017 | Carl von Ossietzky-Universität Oldenburg

Alle Nachrichten aus der Kategorie: Ökologie Umwelt- Naturschutz >>>

Die aktuellsten Pressemeldungen zum Suchbegriff Innovation >>>

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

Im Focus: Metamaterial mit Dreheffekt

Mit 3D-Druckern für den Mikrobereich ist es Forschern des Karlsruher Instituts für Technologie (KIT) gelungen ein Metamaterial aus würfelförmigen Bausteinen zu schaffen, das auf Druckkräfte mit einer Rotation antwortet. Üblicherweise gelingt dies nur mit Hilfe einer Übersetzung wie zum Beispiel einer Kurbelwelle. Das ausgeklügelte Design aus Streben und Ringstrukturen, sowie die zu Grunde liegende Mathematik stellen die Wissenschaftler in der aktuellen Ausgabe der renommierten Fachzeitschrift Science vor.

„Übt man Kraft von oben auf einen Materialblock aus, dann deformiert sich dieser in unterschiedlicher Weise. Er kann sich ausbuchten, zusammenstauchen oder...

Im Focus: Proton-Rekord: Magnetisches Moment mit höchster Genauigkeit gemessen

Hochpräzise Messung des g-Faktors elf Mal genauer als bisher – Ergebnisse zeigen große Übereinstimmung zwischen Protonen und Antiprotonen

Das magnetische Moment eines einzelnen Protons ist unvorstellbar klein, aber es kann dennoch gemessen werden. Vor über zehn Jahren wurde für diese Messung der...

Im Focus: New proton record: Researchers measure magnetic moment with greatest possible precision

High-precision measurement of the g-factor eleven times more precise than before / Results indicate a strong similarity between protons and antiprotons

The magnetic moment of an individual proton is inconceivably small, but can still be quantified. The basis for undertaking this measurement was laid over ten...

Im Focus: Reibungswärme treibt hydrothermale Aktivität auf Enceladus an

Computersimulation zeigt, wie der Eismond Wasser in einem porösen Gesteinskern aufheizt

Wärme aus der Reibung von Gestein, ausgelöst durch starke Gezeitenkräfte, könnte der „Motor“ für die hydrothermale Aktivität auf dem Saturnmond Enceladus sein....

Im Focus: Frictional Heat Powers Hydrothermal Activity on Enceladus

Computer simulation shows how the icy moon heats water in a porous rock core

Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

IHR
JOB & KARRIERE
SERVICE
im innovations-report
in Kooperation mit academics
Veranstaltungen

Mathematiker-Jahrestagung DMV + GDM: 5. bis 9. März 2018 an Uni Paderborn - Über 1.000 Teilnehmer

24.11.2017 | Veranstaltungen

Forschungsschwerpunkt „Smarte Systeme für Mensch und Maschine“ gegründet

24.11.2017 | Veranstaltungen

Schonender Hüftgelenkersatz bei jungen Patienten - Schlüssellochchirurgie und weniger Abrieb

24.11.2017 | Veranstaltungen

 
VideoLinks
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Mathematiker-Jahrestagung DMV + GDM: 5. bis 9. März 2018 an Uni Paderborn - Über 1.000 Teilnehmer

24.11.2017 | Veranstaltungsnachrichten

Maschinen über die eigene Handfläche steuern: Nachwuchspreis für Medieninformatik-Student

24.11.2017 | Förderungen Preise

Treibjagd in der Petrischale

24.11.2017 | Biowissenschaften Chemie