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 Greenhouse gases unbalanced
25.03.2015 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

nachricht Nova Southeastern University researcher part of team researching DNA of tigers
23.03.2015 | Nova Southeastern 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: Neurochip für die Hirnforschung erfolgreich im Markt

Neues Mess- und Stimulationssystem nimmt die Kommunikation von Nervenzellen in Echtzeit auf und ermöglicht damit lang erhoffte Grundlagenforschung

Für die Enträtselung neurologischer und neurodegenerativer Erkrankungen wie Parkinson, Alzheimer, Depression oder verschiedene Erblindungsformen verspricht ein...

Im Focus: Klassisch oder nicht? Physik der Nanoplasmen

Die Wechselwirkung von intensiven Laserpulsen mit Partikeln auf einer Nanometer-Skala resultiert in der Erzeugung eines expandierenden Nanoplasmas.

In der Vergangenheit wurde die Dynamik eines Nanoplasmas typischerweise durch klassische Phänomene wie die thermische Emission von Elektronen beschrieben. Im...

Im Focus: Klimawandel: Nur auf der Erde, nicht auf dem Mars

Löcher in der Polkappe sind natürlichen Ursprungs

Eine Klimaerwärmung findet auf dem Mars trotz schmelzender Polkappen nicht statt. Zu diesem Ergebnis ist eine Studie der University of Arizona http://www.arizona.edu...

Im Focus: Experiment Provides the Best Look Yet at 'Warm Dense Matter' at Cores of Giant Planets

In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...

Im Focus: Energieautark und kabellos: Neuartiges Messsystem schützt Schiffe vor Ausfällen

Wie der Schiffsverkehr zuverlässiger werden kann, während gleichzeitig der Instandhaltungsaufwand sinkt, zeigt das IPH bei der Hannover Messe 2015. Gemeinsam mit Projektpartnern hat das hannoversche Forschungsinstitut ein Sensorsystem entwickelt, das den Zustand von Schiffsgetrieben permanent überwacht und so Ausfällen vorbeugt. Das Besondere: Das Überwachungssystem funktioniert drahtlos und energieautark. Der benötigte Strom wird dort erzeugt, wo er gebraucht wird – direkt am Sensor.

Autos müssen regelmäßig zum TÜV, Schiffe müssen zur Inspektion – denn wenn mitten im Verkehr der Antrieb ausfällt, ist das nicht nur ärgerlich, sondern auch...

Alle Focus-News des Innovations-reports >>>

Anzeige

Anzeige

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

Technologietag bei der SCHOTT AG - Neue Strukturierungstechnologien für Dünngläser

26.03.2015 | Veranstaltungen

7th Mildred Scheel Cancer Conference

26.03.2015 | Veranstaltungen

Corporate Venturing als Quelle unternehmerischer Innovationen

26.03.2015 | Veranstaltungen

 
B2B-VideoLinks
Weitere VideoLinks >>>
Aktuelle Beiträge

Künstliche Muskeln: Gelenkiger Spinnen-Greifer für Industrieroboter passt sich dem Werkstück an

26.03.2015 | HANNOVER MESSE

Technologietag bei der SCHOTT AG - Neue Strukturierungstechnologien für Dünngläser

26.03.2015 | Veranstaltungsnachrichten

Bislang bester Blick auf Staubwolke, die am Schwarzen Loch im Zentrum der Milchstraße vorbeizog

26.03.2015 | Physik Astronomie