Featured Research

from universities, journals, and other organizations

New insights into genomics of speciation

Date:
May 12, 2010
Source:
University of Notre Dame
Summary:
New research could herald an important shift in thinking about the genomics of speciation. The prevailing assumption about how the genomes of newly forming species should differ during the earliest stages of divergence with gene flow speciation is that it will be characterized by a few regions of strong differentiation. New evidence suggests that instead, speciation in the classic apple maggot fly involves genome-wide differentiation driven by natural selection.

New experimental and genomic evidence suggests that contrary to the prevailing assumption, speciation in the classic apple maggot fly system Rhagoletis pomonella involves genome-wide differentiation driven by natural selection.
Credit: Image courtesy of University of Notre Dame

A new study by a team of researchers led by University of Notre Dame biologist Jeffrey Feder could herald an important shift in thinking about the genomics of speciation.

The paper appears in the Proceedings of the National Academy of Sciences.

The prevailing assumption among scientists about how the genomes of newly forming species should differ during the earliest stages of divergence with gene flow speciation is that it will be characterized by a few regions of strong differentiation, amidst a remainder of the genome that remains unaffected by natural selection and thus relatively undifferentiated. This analogy of "genomic islands of speciation" has come to dominate the evolutionary genetics community.

"The island concept has crystallized around an attractive hypothesis termed 'divergence hitchhiking,' in which selection on one or a few genomic regions drives speciation," Feder said.

In the new paper, Feder and his colleagues report experimental and genomic evidence that contrary to the prevailing assumption, speciation in the classic apple maggot fly system Rhagoletis pomonella involves genome-wide differentiation driven by natural selection.

"Our result in Rhagoletis conflicts with the current thinking about how the genomes of newly forming species could differ during the earliest stages of divergence-with-gene-flow speciation," Feder said. "Rather than finding just isolated 'genomic islands' of genetic divergence, we instead discovered 'continents' of divergence encompassing large swaths of the genome."

He points out that past work on the genomics of speciation lacked experimental data and thus may have been unable to detect genomic regions under weaker natural selection, establishing a view of speciation involving genetic divergence in just a few, isolated genomic islands.

Rhagoeitis pomonella fruit flies originally attacked the fruit of hawthorn trees. But about 150 years ago, a portion of the hawthorn fly population shifted and began to feed on apples. In ecologically adapting to apples as a new host plant, apple flies are becoming genetically distinct and reproductively isolated from hawthorn flies. Apple and hawthorn flies are therefore considered to represent "host races" in the early stages of actively diverging into species. As such, the apple and hawthorn races of Rhagoeitis pomonella provided Feder and his fellow researchers a unique opportunity to conduct a direct experimental test of the island versus continents hypotheses.

"This type of comprehensive data, particularly the experimental results, are missing from the bevy of genome scan studies performed in the last few years lending support to the island hypothesis," Feder said. "Without experimental data on responses to selection, these genome scan studies alone can be biased toward identifying isolated outer loci, supporting the island hypothesis.

"We foresee that as mass genotyping techniques continue to advance, it will be these types of inquires and questions that come to dominate the emerging field of population genomics and speciation. We hope our study offers a glimpse of what the future may look like."

The research was funded by the National Science Foundation and the United States Department of Agriculture.


Story Source:

The above story is based on materials provided by University of Notre Dame. The original article was written by William G. Gilroy. Note: Materials may be edited for content and length.


Journal Reference:

  1. Andrew P. Michel, Sheina Sim, Thomas H. Q. Powell, Michael S. Taylor, Patrik Nosil, Jeffrey L. Feder. Widespread genomic divergence during sympatric speciation. Proceedings of the National Academy of Sciences, 2010; DOI: 10.1073/pnas.1000939107

Cite This Page:

University of Notre Dame. "New insights into genomics of speciation." ScienceDaily. ScienceDaily, 12 May 2010. <www.sciencedaily.com/releases/2010/05/100510161336.htm>.
University of Notre Dame. (2010, May 12). New insights into genomics of speciation. ScienceDaily. Retrieved August 21, 2014 from www.sciencedaily.com/releases/2010/05/100510161336.htm
University of Notre Dame. "New insights into genomics of speciation." ScienceDaily. www.sciencedaily.com/releases/2010/05/100510161336.htm (accessed August 21, 2014).

Share This




More Fossils & Ruins News

Thursday, August 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Neanderthals Probably Died Out Earlier Than We Thought

Neanderthals Probably Died Out Earlier Than We Thought

Newsy (Aug. 21, 2014) — A new study is packed with interesting Neanderthal-related findings, including a "definitive answer" to when they went extinct. Video provided by Newsy
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) — Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
Mother And Son Find Woolly Mammoth Tusks 22 Years Apart

Mother And Son Find Woolly Mammoth Tusks 22 Years Apart

Newsy (Aug. 15, 2014) — A mother and son in Alaska uncovered woolly mammoth tusks in the same river more than two decades apart. Video provided by Newsy
Powered by NewsLook.com
Fossils Reveal Ancient Flying Reptile With 'Butterfly Head'

Fossils Reveal Ancient Flying Reptile With 'Butterfly Head'

Newsy (Aug. 14, 2014) — Newly found fossils reveal a previously unknown species of flying reptile with a really weird head, which some say looks like a butterfly. Video provided by Newsy
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