Navigation Links
Study suggests past climate changes may have promoted the formation of new species in the Amazon

AUSTIN, TEXASThe results of a new study suggest that past climate changes and sea level fluctuations may have promoted the formation of new species in the Amazon region of South America.

Today, the Amazon basin is home to the richest diversity of life on earth, yet the reasons why this came to be are not well understood. A team of American and Brazilian researchers studied three species of leafcutter ants from Central and South America to determine how geography and climate affect the formation of new species. Their results will be published July 23 in the journal PLoS ONE.

"One way in which our study is unique is that we looked at an insect. Previous studies have focused mostly on birds, mammals and other vertebrates, whereas insects actually represent the majority of the animal diversity in the Amazon," said Dr. Scott Solomon, the lead author on the study.

Climate changes during the last ice age affected where Amazonian species, such as leafcutter ants, were able to live, restricting some to isolated "refugia" that could cause them to evolve into new species.

"During the last ice age the Amazon region was cooler and drier than it is today, although it was probably still mostly covered by forests," said Solomon.

By comparing the climatic conditions where the species live today with models of what the climate was like in the past using a computational method called maximum entropy, the researchers estimated exactly where each species was capable of living during the last ice age, approximately 21,000 years ago. The researchers then tested their estimates using DNA sequence information from each species and found that the patterns matched up, suggesting that the ancient climate changes left a genetic signature on the ants that is still detectable today.

Prior to the last ice age, rising sea levels may have also played a role in separating populations. Parts of South America that are today covered in rainforest may have been underwater between 10-15 million years ago, according to the researchers. This would have caused higher elevation regions nearby, like the slopes of the Andes mountains, to become like islands, in which species were able to evolve independently from species on other "islands."

According to the study, the genetic evidence was consistent with both scenarios, suggesting that both ice age climate changes as well as flooding of the Amazon basin could be responsible for generating diversity in leafcutter ants.

The authors rejected the idea, previously suggested by other scientists, that rivers play a role in generating diversity in the Amazon basin by separating populations that live on either side. According to the study, even the Amazon riverwhich at places is nearly 2 miles widehas not kept winged leafcutter ant queens and males from flying across it.

"It is interesting that Amazonian rivers acts as barriers to some birds, but these ants are apparently able to cross them," said Solomon.

According to the authors, the idea that refugia were responsible for generating species diversity in the Amazon has been heavily criticized. However, the new findings suggest that the refugia theory may need to be reevaluated.

"Even though we found support for the refugia hypothesis, our results suggest that climate changes had a different effect on each species, even though they are very closely related. This goes against the way people have thought about refugia in the past, and it highlights how difficult it is to generalize when it comes to making predictions about how climate change affects species," said Solomon.


Contact: Scott E. Solomon
Public Library of Science

Related biology news :

1. Sugar study is sweetener for stem cell science
2. MSU researcher uses grant to study little-known but largely useful microbes
3. Scripps study sets high economic value on threatened Mexican mangroves
4. Study reveals air pollution is causing widespread and serious impacts to ecosystems
5. Gene panel predicts lung cancer survival, study finds
6. Study: Migrant laborers valuable to horticulture industry
7. Study shows increased education on nanotech, human enhancement increases public concerns
8. Study: Future snowmelt in West twice as early as expected; threatens ecosystems and water reserves
9. UCLA study identifies mechanism behind mind-body connection
10. Y chromosome study sheds light on Athapaskan migration to southwest US
11. UCSB researcher leads worldwide study on marine fossil diversity
Post Your Comments:
(Date:6/27/2016)... June 27, 2016 Research and Markets has ... 2016-2020" report to their offering. ... America to grow at a CAGR of 12.28% during ... based on an in-depth market analysis with inputs from industry experts. ... the coming years. The report also includes a discussion of the ...
(Date:6/22/2016)... American College of Medical Genetics and Genomics was once again ... of the fastest-growing trade shows during the Fastest 50 Awards ... Las Vegas . Winners are ... of the following categories: net square feet of paid exhibit ... 2015 ACMG Annual Meeting was ranked 23 out of 50 ...
(Date:6/22/2016)... 2016   Acuant , the leading ... has partnered with RightCrowd ® to ... Management, Self-Service Kiosks and Continuous Workforce Assurance. ... functional enhancements to existing physical access control ... with an automated ID verification and authentication ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... Lemonade Stand Foundation (ALSF), a leading national childhood cancer ... bioinformatics lab, using ,big data, to advance the pace ... Liz Scott , co-executive director of ALSF and Alex,s ... Washington, D.C. , hosted by Vice President ... pediatric cancer research and awareness. The ...
(Date:6/27/2016)... , June 27, 2016  Global demand for ... percent through 2020 to $7.2 billion.  This market ... beverages, cleaning products, biofuel production, animal feed, and ... diagnostics, and biocatalysts). Food and beverages will remain ... by increasing consumption of products containing enzymes in ...
(Date:6/27/2016)... ON , June 27, 2016 /PRNewswire/ - BIOREM Inc. ... has been advised by its major shareholders, Clean Technology ... United States based venture capital ... shares of Biorem (on a fully diluted, as converted ... the disposition of their entire equity holdings in Biorem ...
(Date:6/27/2016)... SAN DIEGO , June 27, 2016  Sequenom, ... company committed to enabling healthier lives through the development ... Supreme Court of the United States ... Federal courts that the claims of Sequenom,s U.S. Patent ... the patent eligibility criteria established by the Supreme Court,s ...
Breaking Biology Technology: