I recently received a Digital Education Innovation Grant to design an interactive project exploring animal vision. You can check out the project and read more about the inspiration below.
Speciation starts small. The path of divergence starts with minute change in just a handful of basepairs among the billions of bases in a genome. Overtime, these small differences create feedbacks that propagate further divergence.
That’s the idea of sympatric speciation, the emergence of two species out of one. I’m most interested in the very first steps of this process, but catching this kind of small-scale divergence is hard, because the difference are small and easy to overlook. We call noticeable differences within a species polymorphisms. In most cases, we notice polymorphisms that we can see. For instance, it is hard to miss difference in color morphs of chimpmunks. Many of the classic examples of polymorphisms are visually detectable: industrial melanism in moths, beak size in Galapagos finches, stripe and color pattern in Timema stick insects, etc.
But many polymorphisms cannot be detected visually. For instance, polymorphism in dart frogs is often detected by the chemical composition of their skin toxins. Divergence in birds is often diagnosed by the sound of their calls. I’m in the middle of a collaboration to detect possible divergence in clover populations within and outside of cities via cyanogenesis.
The reliance on our human sight to detect polymorphisms is a problem because human sight, while impressive, is very narrowly limited. There is no reason for us to expect that the most relevant variation (from an ecological or evolutionary perspective) in a population would fall within the range of our senses. For instance, there is a whole vision of the world in the ultra-violet frequency that we cannot see. Flowers that all appear a uniform color to you and me can exhibit huge variation in ultra-violet light. Since birds and bees see ultraviolet, it stands to reason that the strongest selection for divergence would occur in this frequency, completely unknown to us.
All of this led me to think about how we, as eco-evo scientists, can start to shift our paradigm to think about the world through the senses of the organisms we study, which would give us a much better ecological picture of the selection pressures maintaining polymorphisms. The first step, is to take one small step outside of our anthropocentric sense and see the world through the eyes of animals. Thanks to the Yale Center for Teaching and Learning, I was able to design an interactive digital project that helps take those first few steps along a Proustian walk.