Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

One fig, one wasp? Not always!

28.04.2003


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.


Dr. Drude Molbo | EurekAlert!
Further information:
http://www.si.edu/

More articles from Life Sciences:

nachricht Polymers Based on Boron?
18.01.2018 | Julius-Maximilians-Universität Würzburg

nachricht Bioengineered soft microfibers improve T-cell production
18.01.2018 | Columbia University School of Engineering and Applied Science

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

Im Focus: A thermometer for the oceans

Measurement of noble gases in Antarctic ice cores

The oceans are the largest global heat reservoir. As a result of man-made global warming, the temperature in the global climate system increases; around 90% of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Polymers Based on Boron?

18.01.2018 | Life Sciences

Bioengineered soft microfibers improve T-cell production

18.01.2018 | Life Sciences

World’s oldest known oxygen oasis discovered

18.01.2018 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>