Featured Research

from universities, journals, and other organizations

Darwin Was Right About How Evolution Can Affect Whole Group

Date:
November 20, 2008
Source:
McGill University
Summary:
Worker ants of the world, unite! You have nothing to lose but your fertility. The highly specialized worker castes in ants represent the pinnacle of social organization in the insect world. As in any society, however, ant colonies are filled with internal strife and conflict. So what binds them together? More than 150 years ago, Charles Darwin had an idea and now he's been proven right.

Worker ants of the world, unite! You have nothing to lose but your fertility.
Credit: iStockphoto/Mark Evans

Worker ants of the world, unite! You have nothing to lose but your fertility. The highly specialized worker castes in ants represent the pinnacle of social organization in the insect world. As in any society, however, ant colonies are filled with internal strife and conflict. So what binds them together? More than 150 years ago, Charles Darwin had an idea and now he's been proven right.

Related Articles


Evolutionary biologists at McGill University have discovered molecular signals that can maintain social harmony in ants by putting constraints on their fertility. Dr. Ehab Abouheif, of McGill's Department of Biology, and post-doctoral researcher, Dr. Abderrahman Khila, have discovered how evolution has tinkered with the genes of colonizing insects like ants to keep them from fighting amongst themselves over who gets to reproduce.

"We've discovered a really elegant developmental mechanism, which we call 'reproductive constraint,' that challenges the classic paradigm that behaviour, such as policing, is the only way to enforce harmony and squash selfish behaviour in ant societies," said Abouheif, McGill's Canada Research Chair in Evolutionary Developmental Biology.

Reproductive constraint comes into play in these ant societies when evolutionary forces begin to work in a group context rather than on individuals, the researchers said. The process can be seen in the differences between advanced ant species and their more primitive cousins. The study was published in the Nov. 18 edition of the Proceedings of the National Academy of Sciences.

Ants – organized in colonies around one or many queens surrounded by their specialized female workers – are classic examples of what are called eusocial organisms.

"More primitive, or ancestral, ants tend to have smaller colony sizes and have much higher levels of conflict over reproduction than the more advanced species," Abouheif explained. "That's because the workers have a much higher reproductive capacity and there is conflict with the queen to produce offspring."

To their surprise, Khila and Abouheif discovered that "evolution has tinkered with the molecular signals that are used by the egg to determine what's going to be the head and what's going to be the tail, to stop the worker ants from producing viable offspring," Abouheif explained. "Different species of ants have different levels of this "reproductive constraint," and we believe those levels provide a measure of how eusocial the colony is. The less the workers reproduce, the more coherent the group becomes."

The existence of sterile castes of ants tormented Charles Darwin as he was formulating his Theory of Natural Selection, and he described them as the "one special difficulty, which at first appeared to me insuperable, and actually fatal to my theory." If adaptive evolution unfolds by differential survival of individuals, how can individuals incapable of passing on their genes possibly evolve and persist?

Darwin proposed that in the case of ant societies natural selection applies not only to the individual, because the individual would never benefit by cutting its own reproduction, but also to the family or group. This study supports Darwin's prescient ideas, and provides a molecular measure of how an entire colony can be viewed as a single or "superorganism."


Story Source:

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


Cite This Page:

McGill University. "Darwin Was Right About How Evolution Can Affect Whole Group." ScienceDaily. ScienceDaily, 20 November 2008. <www.sciencedaily.com/releases/2008/11/081119122634.htm>.
McGill University. (2008, November 20). Darwin Was Right About How Evolution Can Affect Whole Group. ScienceDaily. Retrieved November 23, 2014 from www.sciencedaily.com/releases/2008/11/081119122634.htm
McGill University. "Darwin Was Right About How Evolution Can Affect Whole Group." ScienceDaily. www.sciencedaily.com/releases/2008/11/081119122634.htm (accessed November 23, 2014).

Share This


More From ScienceDaily



More Fossils & Ruins News

Sunday, November 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Amphipolis Tomb Architraves Reveal Faces

Amphipolis Tomb Architraves Reveal Faces

AFP (Nov. 22, 2014) — Faces in an area of mosaics is the latest find by archaeologists at a recently discovered tomb dating back to fourth century BC and the time of Alexander the Great in Greece. Duration: 01:05 Video provided by AFP
Powered by NewsLook.com
US Returns Looted Artifacts to Thailand

US Returns Looted Artifacts to Thailand

AFP (Nov. 19, 2014) — The United States has returns over 500 vases, bowls, axes, and other ancient artifacts mostly from the Ban Chiang archaeological site which were illegally looted from Thailand decades ago. Duration: 01:13 Video provided by AFP
Powered by NewsLook.com
How To Search Through Every Public Tweet Sent Since 2006

How To Search Through Every Public Tweet Sent Since 2006

Newsy (Nov. 19, 2014) — Twitter has announced improvements to its search index that allow users to search through every public tweet sent since its inception in 2006. Video provided by Newsy
Powered by NewsLook.com
Professor Unlocks the Mystery of Paintings

Professor Unlocks the Mystery of Paintings

AP (Nov. 19, 2014) — Richard Johnson, a computer and engineering professor at Cornell University, is using technology to uncover mysteries about the age and authenticity of historic paintings by artists like Johannes Vermeer and Vincent Van Gogh. (Nov. 19) 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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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