I have been thinking about the Eggplant lately. It perplexes me. When I think of fleshy fruits, I try to think in terms of what reward they offer their animal dispersers. For most, it is sugars – from the mango (dispersed by large ruminants) to the blueberry (dispersed by small birds). This is easy to understand, because sugars are metabolically cheap for the plant to produce. Then there are those few, like avocados and their relatives, which provide lipids as the reward – more expensive from the plant’s point of view, but that is the cost of coevolving with a specialized disperser that requires that.
But the eggplant? It doesn’t have much of a nutritional profile. It doesn’t taste sweet-tart like a tomato, so it wouldn’t seem to attract dispersers who seek sugars. It doesn’t contain much lipid either. As I researched this further, I found that the eggplant was domesticated from the wild Solanum incanum (which some online sources amusingly misspell Solanum insanum, perhaps in reference to old folk beliefs that eggplant caused madness). It so happens I have an observation of it: Bitter Tomato, Okahandja, Namibia. But that brings me no closer to the answer, because that species is known as bitter apple, bitterball, or bitter tomato. What fruit eating animal would be attracted to bitter? Bitter flavors are psychologically thought of as associated with poison, so I cannot imagine a disperser for a bitter fruit.
Any ideas about the original disperser of the eggplant?