Featured Research

from universities, journals, and other organizations

One Fig, One Wasp? Not Always!

Date:
April 29, 2003
Source:
Smithsonian Institution
Summary:
Contrary to prevailing wisdom concerning one of the most famous textbook examples of a tightly co-evolved mutualism, not every fig species is pollinated by its own unique wasp species. In this week's Proceedings of the National Academy of Sciences, Drude Molbo, postdoctoral fellow at the Smithsonian Tropical Research Institute and collaborators report that two genetically distinct species of wasps are present in at least half of the fig species surveyed.

Contrary to prevailing wisdom concerning one of the most famous textbook examples of a tightly co-evolved mutualism, not every fig species is pollinated by its own unique wasp species. In this week's Proceedings of the National Academy of Sciences, Drude Molbo, postdoctoral fellow at the Smithsonian Tropical Research Institute and collaborators report that two genetically distinct species of wasps are present in at least half of the fig species surveyed.

This new result forces a major reassessment of the vast majority of studies that have used figs as model systems. In one stroke, the findings undermine many current ideas concerning the stability and evolution of mutualisms, while simultaneously strengthening other critical parts of modern evolutionary theory. (sex allocation and local mate competition theory).

Wasps began to pollinate and co-evolve with figs 90 million years ago, even before continental drift separated Old and New World groups. There are over 750 recognized fig species. The diversity and ability to measure costs and benefits that each partner provides the other means that the fig-wasp system provides an ideal model for understanding what each partner stands to gain from a mutualistic relationship. In addition, fig wasps have been used extensively as model systems for testing sex ratio theories, adding significantly to our understanding of evolutionary processes. One of the key assumptions for both model systems has been that a unique wasp species pollinates each fig species.

Molbo developed nuclear microsatellite markers to test the sex ratio theory of local mate competition (Hamilton 1967, Herre 1985, 1989, West et al., 2001). But when she used these markers to genotype wasp offspring from different fig fruits, the results didn't make sense. Molbo kept getting different sets of genotypes that had nothing in common with those of wasps that supposedly belonged to the same species.

On closer inspection, some figs hosted two cryptic species of pollinator wasp. Molbo΄s analysis based on nuclear microsatellites matched perfectly with groupings based on mitochondrial genes sequenced by Carlos Machado (STRI and University of Arizona), which confirmed that cryptic wasps had evolved separately for more than 1.5 million years.

Some cryptic wasp species are actually sister species, i.e. they share the same ancestor and probably evolved within a single host fig species or very closely related species. However, genetically identical wasps may also be found on two different fig hosts, suggesting that new associations may also form from time to time. Overall, these findings indicate that even mutualistic relationships can be much more evolutionarily labile than has previously been appreciated.

This finding has important consequences for our understanding of sex ratio evolution and precision of adaptation. Using the molecular markers that Molbo developed, the collaborators found that the observed sex ratios of fig wasps broods actually comes closer to fitting theoretic predictions when multiple wasp species are considered. This finding signficantly strengthens support for one of the clearest examples of the qualitative and quantitative predictive power of modern evolutionary theory.

###

Ref. Cryptic species of fig pollinating wasps: Implications for the evolution of the fig-wasp mutualism, sex allocation and precision of adaptation. Drude Molbo, Carlos Machado, Jan Sevenster, Laurent Keller and Allen Herre. Proceedings of the National Academy of Sciences. May 13, Vol 100, no 10 pp. 5867-5872.

The Smithsonian Tropical Research Institute, headquartered in Panama City, Panama, is one of the world΄s leading centers for research on the ecology, evolution and conservation of tropical organisms.


Story Source:

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


Cite This Page:

Smithsonian Institution. "One Fig, One Wasp? Not Always!." ScienceDaily. ScienceDaily, 29 April 2003. <www.sciencedaily.com/releases/2003/04/030428082254.htm>.
Smithsonian Institution. (2003, April 29). One Fig, One Wasp? Not Always!. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2003/04/030428082254.htm
Smithsonian Institution. "One Fig, One Wasp? Not Always!." ScienceDaily. www.sciencedaily.com/releases/2003/04/030428082254.htm (accessed April 17, 2014).

Share This



More Plants & Animals News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) — Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com
Flamingo Frenzy Ahead of Zoo Construction

Flamingo Frenzy Ahead of Zoo Construction

AP (Apr. 17, 2014) — With plenty of honking, flapping, and fluttering, more than three dozen Caribbean flamingos at Zoo Miami were rounded up today as the iconic exhibit was closed for renovations. (April 17) Video provided by AP
Powered by NewsLook.com
Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) — Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) — A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. 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