Navigation Links
Global climate change: The impact of El Niño on Galápagos marine iguanas
Date:12/12/2007

New Haven, Conn. A before-and-after study led by Yale biologists, of the effects of 1997 El Nio on the genetic diversity of marine iguanas on the Galpagos Islands, emphasizes the importance of studying populations over time and the need to determine which environmental and biological factors make specific populations more vulnerable than others.

According to the authors, recurring El Nio events provide an ideal system to study the impact of human-mediated climate change on ecosystems worldwide, by allowing observation of changes in populations associated with individual events.

Since global warming is expected to cause an increase in the strength and frequency of El Nio events, it is important to evaluate the impact of El Nio on natural populations and their capacity to respond to environmental stresses, said Gisella Caccone, senior research scientist in ecology and evolutionary biology at Yale, and senior author of the paper published this week in the Public Library of Science (PLoS) One.

In this study, the researchers investigated the effect of sea surface warming associated with the single, intense El Nio event of 1997 to 1998 on genetic diversity in Galpagos marine iguana populations. They found that populations within the same species responded very differently.

Collaboration between German scientists who fortuitously collected and archived samples between 1991 and 1993 and Yale researchers who sampled the iguanas in 2004 enabled these unique before-and after comparisons. More than 800 samples from 11 Galpagos marine iguana populations were evaluated.

The researchers looked for changes in levels of genetic variation in nuclear microsatellite DNA and mitochondrial DNA markers of samples collected before and after this El Nino event. Changes in microsatellite frequency are sensitive enough to detect low population sizes before there is a significant loss of diversity in a population, whereas mitochondrial markers only show losses of diversity.

Caccone said that although some populations had mortality rates of up to 90%, only one population from a single island showed strong evidence of a genetic bottleneck, suggesting that the El Nio-induced disturbance affected populations very differently even within the same species.

Our study points out that there was a low population size on the island of Marchena during the same period in which there was serious volcanic activity as well as the El Nino, said Yale graduate student Scott Glaberman, a principal author of the study. Since both of these forces could have acted on the population, it shows the importance of knowing the major forces influencing survival and reproduction to best interpret the results of genetic tests.

The most striking result of our study is that although marine iguanas on some islands had a rather high mortality due to El Nio, the genetic consequences were mostly absent, said author Sebastian Steinfartz a postdoctoral fellow. This unique study shows that natural populations may be able to balance even severe short term climatic disturbances, and that such fluctuations will not necessarily have long-term negative consequences on the population structure.

Basic surveys and ecology of organisms are not the most glamorous aspects of research, but if used together with the exciting genetic approach in our study, they make for a very powerful approach, said Glaberman.

This underscores the importance of having baseline studies for any population of interest, and the value of archiving samples for the use of future research, Caccone said. It sets the basis for future research to determine which environmental and biological factors make specific populations more vulnerable than others.


'/>"/>

Contact: Janet Rettig Emanuel
janet.emanuel@yale.edu
203-432-2157
Yale University  
Source:Eurekalert

Related biology news :

1. Global Warming and the Habitability of Planet Earth, Sept. 26
2. Green skies: Engineers work may reduce jet travels role in global warming
3. Scientists in first global study of poison gas in the atmosphere
4. North Americas northernmost lake affected by global warming
5. IEEE-USA innovation forum will help prepare US tech leaders to prosper in a global marketplace
6. Majority of Americans want local action on global warming, says poll
7. International team of scientists warns of climate changes impact on global river flow
8. Changing the global dietary environment
9. Global deal fuels QUTs world-changing research
10. NIH hosts event to launch Council of Science Editors global theme issue
11. Agricultural soil erosion is not adding to global warming
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Global climate change: The impact of El Niño on Galápagos marine iguanas
(Date:3/22/2017)... March 21, 2017 Optimove , ... by retailers such as 1-800-Flowers and AdoreMe, today ... Recommendations and Replenishment. Using Optimove,s machine learning algorithms, ... product and replenishment recommendations to their customers based ... predictions of customer intent drawn from a complex ...
(Date:3/20/2017)... ALLENTOWN, Pa. , March 20, 2017 ... PD 2.0 personal spirometer and Wellness Management System (WMS), ... Founded in 2010, PMD Healthcare is a ... Company with a mission dedicated to creating innovative solutions ... of life. With that intent focus, PMD developed the ...
(Date:3/9/2017)... Australia , March 9, 2017 /PRNewswire/ ... at the prestigious World Lung Imaging Workshop at the ... Fouras , was invited to deliver the latest data ... This globally recognised event brings together leaders at the ... latest developments in lung imaging. "The ...
Breaking Biology News(10 mins):
(Date:5/23/2017)... Toronto, Canada (PRWEB) , ... May 23, 2017 ... ... of Firmex FileSend, a cloud-based file transfer solution that makes it easy for ... firewall without having to worry about cumbersome FTP software or email file size ...
(Date:5/23/2017)... ... May 22, 2017 , ... ... in San Diego, California, this August will feature high-level speakers on quantum ... vehicles. , SPIE Optics and Photonics, the largest multidisciplinary optical sciences meeting in ...
(Date:5/23/2017)... ... May 23, 2017 , ... Cambridge Semantics , the leading ... year’s Bio-IT World Conference and Expo in Boston May 23-25 with a ... The Anzo Smart Data Lake is also a finalist for the Best of ...
(Date:5/21/2017)... ANGELES, CA (PRWEB) , ... May 19, 2017 ... ... the annual meeting and educational conference of the American Association of Bioanalysts (AAB) ... the Galleria Hotel in Houston. The conference reinforces AAB’s commitment to excellence in ...
Breaking Biology Technology: