Featured Research

from universities, journals, and other organizations

Snail Venoms Reflect Reduced Competition

Date:
May 21, 2009
Source:
University of Michigan
Summary:
A study of venomous snails on remote Pacific islands reveals genetic underpinnings of an ecological phenomenon that has fascinated scientists since Darwin.

A study of venomous snails on remote Pacific islands reveals genetic underpinnings of an ecological phenomenon that has fascinated scientists since Darwin.

The research is by University of Michigan evolutionary biologists Tom Duda and Taehwan Lee.

In the study, Duda and Lee explored ecological release, a phenomenon thought to be responsible for some of the most dramatic diversifications of living things in Earth's history. Ecological release occurs when a population is freed from the burden of competition, either because its competitors become extinct or because it colonizes a new area where few or no competitors are found. When this happens, the "released" population typically expands its diet or habitat, taking over resources that would be off-limits if competitors were present. This expansion is believed to drive the evolution of adaptations for taking advantage of the new resources, such as venoms tailored to a broader array of prey.

"Although there are plenty of examples of populations expanding into a variety of niches after experiencing ecological release, little is known about the evolution of genes associated with this phenomenon," said Duda, an assistant professor in the U-M Department of Ecology and Evolutionary Biology.

To investigate the process, Duda and Lee took advantage of a natural experiment involving a species of cone snails (Conus miliaris), which is found in shallow waters of tropical to subtropical environments from the Red Sea and eastern shores of Africa in the western Indian Ocean to Easter Island and Sala y Gσmez in the southeastern Pacific. In most areas where the species is found, C. miliaris has lots of competitors and preys on only three species of marine worms. But on Easter Island, where it has virtually no competition, the snail's diet is much broader, incorporating many additional species of worms.

Cone snails paralyze their prey with venom made up of various "conotoxins." Because different species---or in some cases even different populations---of cone snails have both distinct prey preferences and distinctly different venom compositions, Duda has speculated that natural selection has shaped particular species' venoms to most effectively paralyze their favored prey.

To test this hypothesis, Duda and Lee looked at two conotoxin genes and compared patterns of variation found in the Easter Island snails with those of snails from Guam and American Samoa, where the snails have not experienced ecological release.

"On Easter Island, where the snails are eating far more things than they're eating elsewhere, we see that different toxins predominate, suggesting that natural selection has operated at these toxin genes," said Duda, who also is a research associate with the Smithsonian Tropical Research Institute. "These results imply that ecological release is associated with strong selection pressures that are associated with the evolution of new ecologies."

The research was funded by the National Geographic Society's Committee for Research and Exploration and the National Science Foundation.


Story Source:

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


Journal Reference:

  1. Duda et al. Ecological Release and Venom Evolution of a Predatory Marine Snail at Easter Island. PLoS ONE, 2009; 4 (5): e5558 DOI: 10.1371/journal.pone.0005558

Cite This Page:

University of Michigan. "Snail Venoms Reflect Reduced Competition." ScienceDaily. ScienceDaily, 21 May 2009. <www.sciencedaily.com/releases/2009/05/090520161330.htm>.
University of Michigan. (2009, May 21). Snail Venoms Reflect Reduced Competition. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2009/05/090520161330.htm
University of Michigan. "Snail Venoms Reflect Reduced Competition." ScienceDaily. www.sciencedaily.com/releases/2009/05/090520161330.htm (accessed July 23, 2014).

Share This




More Plants & Animals News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Stone Fruit Listeria Scare Causes Sweeping Recall

Stone Fruit Listeria Scare Causes Sweeping Recall

Newsy (July 22, 2014) — The Wawona Packing Company has issued a voluntary recall on the stone fruit it distributes due to a possible Listeria outbreak. Video provided by Newsy
Powered by NewsLook.com
Michigan Plant's Goal: Flower and Die

Michigan Plant's Goal: Flower and Die

AP (July 22, 2014) — An 80-year-old agave plant, which is blooming for the first and only time at a University of Michigan conservatory, will die when it's done (July 22) Video provided by AP
Powered by NewsLook.com
Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Huge Schizophrenia Study Finds Dozens Of New Genetic Causes

Newsy (July 22, 2014) — The 83 new genetic markers could open dozens of new avenues for schizophrenia treatment research. Video provided by Newsy
Powered by NewsLook.com
CDC Head Concerned About a Post-Antibiotic Era

CDC Head Concerned About a Post-Antibiotic Era

AP (July 22, 2014) — Sounding alarms about the growing threat of antibiotic resistance, CDC Director Tom Frieden warned Tuesday if the global community does not confront the problem soon, the world will be living in a devastating post-antibiotic era. (July 22) Video provided by AP
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