Featured Research

from universities, journals, and other organizations

Research into oaks helps us understand climate change

Date:
August 2, 2012
Source:
University of Notre Dame
Summary:
Biologists are tracking the evolution of the live oaks of eastern North America, seeking to understand how the trees adapted to climate change during glacial periods.

Jeanne Romero-Severson, associate professor of biological sciences at the University of Notre Dame, and her collaborators, are tracking the evolution of the live oaks of eastern North America, seeking to understand how the trees adapted to climate change during glacial periods.

When the ice advanced, the oaks retreated. When the ice retreated the oaks advanced, spreading from tropical to temperate zones, up from Central America and Mexico into the Piedmont Carolinas. The researchers expect the study of live oak migrations and phylogeny will provide clues to the success of the oaks that range up into northern Ontario in Canada.

Oaks originated in southeast Asia before the continents split and migrated both east and west, but North America has far more species than other regions. Researchers have long suspected that repeated climate challenges might have led to this diversity. Previous studies have shown that the live oaks that live in Mexico cannot survive the Carolina winters. This shows that there are genetic differences between the southern live oaks and their northern descendants.

"In Mexico, live oaks do not experience repeated cycles of freezing and thawing," Romero-Severson says. "Are the live oak species that now live further north different species because of this cold tolerance? What about the live oak species that span the tropical-temperate divide? It is logical to assume there is a genetic basis for the ability to survive in those cold temperatures. With four groups of researchers working together, we can tease out how it was that oaks were able to adapt to the climate as they moved north. What were the genetic changes they underwent?"

Romero-Severson focuses on genetics and genomics of the oaks. Andrew Hipp of the Morton Arboretum in Lisle, Ill., is studying their morphological differences; Paul Manos of Duke University is studying their systematics (family trees based on DNA markers); and Jeannine Cavender-Bares of the University of Minnesota is studying their ecophysiology, including the survival of seedlings in cold temperatures. A National Science Foundation grant supports the research.

The team hypothesizes that trees in contact with relatives who could just manage to survive in the cold were able to "capture" from these relatives a few genes favorable for survival in colder climates, without retaining extensive genetic changes that would alter their morphology. Different animal species rarely hybridize in nature and when they do, the offspring are often sterile, like mules. Different forest tree species often make fertile interspecific hybrids, but the parent species remain morphologically distinct.

"It's a mystery to us how oak species can have rampant interspecies hybridization and yet maintain species distinction, but they do," Romero-Severson says. "Favorable gene combinations from one live oak species can be captured by any other live oak species." There might be an "interspecific hybrid screen," a process that retains a relatively small number of good genes that equip the species for successful northward migration, while maintaining all the other genes that determine species identity.

Identification of the genetic changes in the relatively small number of live oak species in the southeastern United States and Mexico can provide clues for study of the more extensive deciduous red and white oaks, which reach from the Caribbean into California to the west and up into Canada from the east. Eastern North America alone has more than two dozen red oak species and close to two dozen white oak species. Some regions in the southeastern United States have the highest concentration of oak species in the world.

"Our hypothesis is that the same set of genes is involved in cold tolerance in all of these species," Romero-Severson says. "We feel that we have defined the problem so carefully that what we learn from these live oaks will help us understand how evolution works, and how natural adaptation arises. Our goal is to understand the role of hybridization in the evolution of forest trees and how forest trees actually respond to rapid climate change."

Romero-Severson, who came to Notre Dame in 2003, is also part of a team of researchers from seven universities with an NSF grant to develop genomics tools for finding the genetic basis for tolerance to the introduced insects and diseases that threaten the nation's hardwood trees.


Story Source:

The above story is based on materials provided by University of Notre Dame. Note: Materials may be edited for content and length.


Cite This Page:

University of Notre Dame. "Research into oaks helps us understand climate change." ScienceDaily. ScienceDaily, 2 August 2012. <www.sciencedaily.com/releases/2012/08/120802184011.htm>.
University of Notre Dame. (2012, August 2). Research into oaks helps us understand climate change. ScienceDaily. Retrieved April 16, 2014 from www.sciencedaily.com/releases/2012/08/120802184011.htm
University of Notre Dame. "Research into oaks helps us understand climate change." ScienceDaily. www.sciencedaily.com/releases/2012/08/120802184011.htm (accessed April 16, 2014).

Share This



More Plants & Animals News

Wednesday, April 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Outbreak Now Linked To 121 Deaths

Ebola Outbreak Now Linked To 121 Deaths

Newsy (Apr. 15, 2014) The ebola virus outbreak in West Africa is now linked to 121 deaths. Health officials fear the virus will continue to spread in urban areas. Video provided by Newsy
Powered by NewsLook.com
In Washington, a Push to Sterilize Stray Cats

In Washington, a Push to Sterilize Stray Cats

AFP (Apr. 14, 2014) To curb the growing numbers of feral cats in the US capital, the Washington Humane Society is encouraging residents to set traps and bring the animals to a sterilization clinic, after which they are released.. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
After Attack, Officials Kill 5 Bears in Florida

After Attack, Officials Kill 5 Bears in Florida

AP (Apr. 14, 2014) Florida wildlife officials say they have killed five bears following an attack on a woman in a suburban subdivision in central Florida. Forty-five year-old Terri Frana was attacked by a large bear in her driveway Saturday. (April 14) Video provided by AP
Powered by NewsLook.com
Uruguay Opens Its First Cannabis Library

Uruguay Opens Its First Cannabis Library

AFP (Apr. 13, 2014) Uruguay opened its first Cannabis Library in Montevideo on Saturday, where people can come and read books on cannabis or take classes on how to grow the plant or even how to cook with it. Duration: 01:20 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins