Fig and fig wasp coevolution
By: Caroline Colbert, Brianne Horton, and Brianna Salah (Stonehill College Evolution Fall 2017)
I’m sure you’re all familiar with the sweet and delicious taste of a Fig Newton, but did you know that the mutualistic relationship between fig plants and their pollinator wasps is to thank for this delicious snack. Also, did you know that this relationship is the result of millions of years of coevolution? Read on to learn more about this unique relationship!
The relationship between figs and fig wasps is what is often referred to as obligate mutualism, a common type of symbiosis between species that occurs when both organisms not only benefit from their shared relationship, but actually rely on one another for their survival. This relationship is unique however because even though there are well over 900 different species of figs and fig wasps, each individual species of the wasps will only pollinate one corresponding species of fig plant.
Against common belief, figs are not your typical fruits, but actually inverted flowers commonly referred to as multiple fruits. This means that pollination must occur inside the fig, where the flowers (i.e. their reproductive organs) are found. So how does pollination take place inside if there is only one tiny opening in the bottom of the fruit?
Well, that is where the tiny fig wasps come in to do their job. When the fig is ready for pollination, it will emit a scent from its fruit that attracts females of the corresponding species of fig wasps. The female wasps will wiggle their way through the small opening, often losing their wings and antenna along the way. Once inside, the female will lay her eggs into the fig and pollinate its flowers simultaneously. Therefore, it is clear that the female fig is benefitting by maintaining a safe place to lay her eggs, whereas the fig plant is benefiting from the pollination that will allow it to produce seeds and further development.
While conducting research on the fig wasp and F. septica relationship, we focused on the article, “Diversification and spatial structuring in the mutualism between Ficus septica and its pollinating wasps in insular South East Asia.” In order to investigate this obligate mutualism, Dr. Lillian Rodriquez, who resides and teaches in the Philippians, and her team of researchers set out to South East Asia to investigate the coexistence of several wasp species in the same areas.
We were luckily able to come in contact with Dr. Rodriquez, who chose to conduct her research on this relationship because, “[she has] always had an affinity for plants since [she] was a kid, but when [she] got introduced to how ants and plants can benefit each other, [she] immediately fell in love with mutualisms. In the Philippines, [they] have about one hundred fig species so it was a very easy decision to start working on the fig and fig wasp’s system. [The researchers] decided to work on the specific research question because very few studies have looked at how mutualisms diversify. With the Ficus septica fig wasp system [they] have a unique system that is in the process of diversification, this provides [them] with an opportunity to investigate diversification and evolution as it happens and not just after it has happened.”
Multiple clades of wasps and fig plants are able to live in the same area without signs of competition, which led the researchers to believe that figs and fig plants are evolving together, with one species of wasps only pollinating one species of fig plant (and vice versa). The team of researchers hypothesized that this phenomenon was caused by the coevolution between figs and fig wasps, related to their obligate mutualism. Through this podcast, “The Buzz About Bees,” we hope that we are able to share the excitement of Dr. Rodriquez and her team of researchers for this topic with all of our listeners.
For more information, please check out our Twitter (@FigWasp_Fanatic) and contact us through our hashtag (#FigWaspMutualism).
Published Research (https://bmcevolbiol.biomedcentral.com/articles/10.1186/s12862-017-1034-8)
Author’s Website (http://www.biology.upd.edu.ph/?page_id=794)
Our Twitter Page (https://twitter.com/FigWasp_Fanatic)
Article: Rodriguez, L. J., Bain, A., Chou, L.-S., Conchou, L., Cruaud, A., Gonzales, R., … Kjellberg, F. (2017). Diversification and spatial structuring in the mutualism between Ficus septica and its pollinating wasps in insular South East Asia. BMC Evolutionary Biology, 17, 207. http://doi.org/10.1186/s12862-017-1034-8
Music: Guitalele’s Happy Place composed by Stefan Kartenberg (http://dig.ccmixter.org/files/JeffSpeed68/56194)
Picture: Parasitic wasps on sandpaper fig 7431 by Malcolm Tatterasall (https://flic.kr/p/Z5MAAo)
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