Monday, September 17, 2012

Evolution
The Wonder of the Fig
(Part 1)

In this series of posts on the fig, we’ll look over the evolution of the Ficus genus that has over 850 species of trees in it (and only 2 of them bear edible fruits/flowers, edible for us humans that is). But figs are just half of the story, as the other half of it will revolve around their pollinators, the tiny little wasps, whose existence is just as dependent on
the fig tree as the fig’s is dependent on the wasp.

In this first post, we’ll first look over the general structure of fig fruit and what exactly it really is. First of all, it’s not a fruit, but actually a “garden enclosed” as fondly dubbed by Richard Dawkins. Although the story takes a general view of them all, it would not be too inaccurate if we keep in mind the edible fig (adjacent picture) while we play this story in our mind.
If we think of a garden as a vast collection of flowers with different pollinators and insects and parasites roaming around, then the fig fruit is indeed an ‘enclosed garden’, for it has all of those elements. This is similar to a Sunflower that is not actually a flower but hundreds of small flowers packed into a mass bed giving the ‘appearance’ of a single flower. When you slice open a fig what you see is hundreds of tiny flowers, both male and female and if you use a lens you may also get to see the tiny insects making a living inside it.

Evolution of the fig:
Picture the fig in your mind. Now, imagine looking at the differences in its structure as we slowly go back in time. If we go back a few centuries or a millennium, the essential structure will remain the same and the fruit will still be easily identifiable. But turn to the scale of millions of years and the wonder unfolds itself- initially through our journey back in time the fig’s small entrance will slowly open up and grow in a bigger hole. Again after rewinding a few million years more the entrance hole will enlarge considerably and the spherical fig will now resemble a cup with the inner layer populated with tiny flowers. Go back a few million years more than that and the cup keeps getting more and more shallow and at one point the small florets will actually be on the “outside” part of the shallow flattened cup. Further back, the little florets become more distinct until they are no more together at all and there is no such thing as a fig fruit. This is evolution of the fig in reverse, and it will be helpful in connecting the dots from the story that follows ahead.

In the next part, we’ll see how wasps, the fig trees’ sole pollinators evolved side-by-side with the figs and the wonderful pollination process of the fig tree.

Sources:
1) ‘Climbing Mount Improbable’, Richard Dawkins, 1996
2) http://nirmukta.com/2012/08/17/the-wonder-of-the-fig/ (my article)
3) www.figweb.org

Related documentary: http://www.youtube.com/watch?v=sxJdweffxEE

Image: http://www.demandfarming.com.au/prosperityfarmingsystems.html

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