Forum für Wissenschaft, Industrie und Wirtschaft

Hauptsponsoren:     3M 
Datenbankrecherche:

 

Rapid Changes in Climate Don’t Slow Some Lizards

27.11.2012
Tropical lizards living in Miami can tolerate colder temperatures than their Puerto Rican cousins

One tropical lizard's tolerance to cold is stiffer than scientists had suspected.


The Puerto Rican lizard Anolis cristatellus pictured above has adapted to the cooler winters of Miami. Credit: Manuel Leal, Duke.

A new study shows that the Puerto Rican lizard Anolis cristatellus has adapted to the cooler winters of Miami. The results also suggest that this lizard may be able to tolerate temperature variations caused by climate change.

"We are not saying that climate change is not a problem for lizards. It is a major problem. However, these findings indicate that the thermal physiology of tropical lizards is more easily altered than previously proposed," said Duke biologist Manuel Leal, co-author of the study, which appears in the Dec. 6 issue of The American Naturalist.

Scientists previously proposed that because lizards were cold-blooded, they wouldn't be able to tolerate or adapt to cooler temperatures.

Humans, however, introduced Puerto Rican native A. cristatellus to Miami around 1975. In Miami, the average temperature is about 10 degrees Celsius cooler in winter than in Puerto Rico. The average summer temperatures are similar.

Leal and his graduate student Alex Gunderson captured A. cristatellus from Miami's Pinecrest area and also from northeastern Puerto Rico. They brought the animals back to their North Carolina lab, slid a thermometer in each lizard's cloaca and chilled the air to a series of cooler temperatures. The scientists then watched how easy it was for the lizards to right themselves after they had been flipped on their backs.

The lizards from Miami flipped themselves over in temperatures that were 3 degrees Celsius cooler than the lizards from Puerto Rico. Animals that flip over at lower temperatures have higher tolerances for cold temperatures, which is likely advantageous when air temperatures drop, Leal said.

"It is very easy for the lizards to flip themselves over when they are not cold or not over-heating. It becomes harder for them to flip over as they get colder, down to the point at which they are unable to do so," he said.

At that point, called the critical temperature minimum, the lizards aren't dead. They've just lost control of their coordination. "It is like a human that is suffering from hypothermia and is beginning to lose his or her balance or is not capable of walking. It is basically the same problem. The body temperature is too cold for muscles to work properly," he said.

Leal explained that a difference of 3 degrees Celsius is "relatively large and when we take into account that it has occurred in approximately 35 generations, it is even more impressive." Most evolutionary change happens on the time scale of a few hundred, thousands or millions of years. Thirty-five years is a time scale that happens during a human lifetime, so we can witness this evolutionary change, he said.

The lizards' cold tolerance also "provides a glimpse of hope for some tropical species," Leal added, cautioning that at present scientists don't know how quickly tolerance to high temperatures -- another important consequence of climate change -- can evolve.

He and Gunderson are now working on the heat-tolerance experiments, along with tests to study whether other lizard species can adjust to colder temperatures.

Citation:

"Rapid Change in the Thermal Tolerance of a Tropical Lizard." Leal, M. and Gunderson, A. (Dec., 2012). The American Naturalist, 180: 6, 815-822. DOI: 10.1086/668077

Ashley Yeager | EurekAlert!
Further information:
http://www.duke.edu

More articles from Ecology, The Environment and Conservation:

nachricht Treating ships’ ballast water: filtration preferable to disinfection
30.07.2015 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Are Fish Getting High on Cocaine?
28.07.2015 | McGill University

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: Gefangen in Ruhelosigkeit

Mit ultrakalten Atomen lässt sich ein neuer Materiezustand beobachten, in dem das System nicht ins thermische Gleichgewicht kommt.

Was passiert, wenn man kaltes und heißes Wasser mischt? Nach einer Weile ist das Wasser lauwarm – das System hat ein neues thermisches Gleichgewicht erreicht....

Im Focus: Quantum Matter Stuck in Unrest

Using ultracold atoms trapped in light crystals, scientists from the MPQ, LMU, and the Weizmann Institute observe a novel state of matter that never thermalizes.

What happens if one mixes cold and hot water? After some initial dynamics, one is left with lukewarm water—the system has thermalized to a new thermal...

Im Focus: Superschneller Wellenritt im Kristall: Elektronik auf Zeitskala einzelner Lichtschwingungen möglich

Physikern der Universitäten Regensburg und Marburg ist es gelungen, die von einem starken Lichtfeld getriebene Bewegung von Elektronen in einem Halbleiter in extremer Zeitlupe zu beobachten. Dabei konnten sie ein grundlegend neues Quantenphänomen entschlüsseln. Die Ergebnisse der Wissenschaftler sind jetzt in der renommierten Fachzeitschrift „Nature“ veröffentlicht worden (DOI: 10.1038/nature14652).

Die rasante Entwicklung in der Elektronik mit Taktraten bis in den Gigahertz-Bereich hat unser Alltagsleben revolutioniert. Sie stellt jedoch auch Forscher...

Im Focus: On the crest of the wave: Electronics on a time scale shorter than a cycle of light

Physicists from Regensburg and Marburg, Germany have succeeded in taking a slow-motion movie of speeding electrons in a solid driven by a strong light wave. In the process, they have unraveled a novel quantum phenomenon, which will be reported in the forthcoming edition of Nature.

The advent of ever faster electronics featuring clock rates up to the multiple-gigahertz range has revolutionized our day-to-day life. Researchers and...

Im Focus: Erster Nachweis von Lithium in einem explodierenden Stern

Erstmals konnte das chemische Element Lithium in der ausgestoßenen Materie einer Nova nachgewiesen werden. Beobachtungen von Nova Centauri 2013 mit Teleskopen des La Silla-Observatoriums der ESO und in der Nähe von Santiago de Chile helfen bei der Aufklärung des Rätsels, warum so viele junge Sterne mehr von diesem Element enthalten als erwartet. Diese Entdeckung liefert ein seit langem fehlendes Teil im Puzzle der chemischen Entwicklungsgeschichte unserer Galaxie und ist ein großer Fortschritt für das Verständnis des Mischungsverhältnisses der chemischen Elemente in den Sternen unserer Milchstraße.

Das leichte chemische Element Lithium ist eines der wenigen Elemente, das nach unserer Modellvorstellung auch beim Urknall vor 13,8 Milliarden Jahren...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

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

Türme und Maste aus Stahl – Neues aus Forschung und Anwendung

31.07.2015 | Veranstaltungen

Tagung „Brandschutz im Tank- und Gefahrgutlager“ am 16. November 2015 im Essener Haus der Technik stellt praktische Lösungen vor

30.07.2015 | Veranstaltungen

12. BMBF-Forum für Nachhaltigkeit: Green Economy, Energiewende und die Zukunft der Städte

30.07.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Wiederaufladbare Batterien machen sich breit

31.07.2015 | Seminare Workshops

Alles zur Kryotechnik: HDT bietet Seminar zum „Kryostatbau“ an

31.07.2015 | Seminare Workshops

Erster Zug von Siemens für Thameslink‑Strecke in UK angekommen

31.07.2015 | Verkehr Logistik