by Carl Strang
The season draws down toward winter, and the photosynthetic labors of the myriad plants are being expressed through the product of their fruits. Plants can’t spread their seeds around without help, though, and this is a good time to compare and contrast the different ways in which evolution has diversified the seed dispersal process. Some use the wind, and this haphazard distribution method only succeeds if lots and lots of seeds are released.
Wrapping the seeds in fruits that animals can eat is more economical in the sense of being more targeted. I often have wondered if purple or black fruits low to the ground specifically are aimed at mammalian dispersers, whose narrowly defined habitual routing increases the chance that a seed will land in a suitable habitat. As a result, fewer seeds need be produced.
And then there are the plants that use us for transport, not because we eat the fruits but because we provide traveling surfaces the seeds can stick to.
All these methods work, of course, otherwise the plants would have vanished long ago.