Convergence, Natural Selection, 'Survival of the Fittest'.

 1. I chose the example of coffee, cacao, and tea all having caffeine.

2. Convergent evolution means that two species with distinct lineages have independently evolved to have similar features.

3. My choice in #1 is an example of convergent evolution because as you can see in the phylogeny below, coffee, tea, and cacao are the only three species of these closely related plants that have evolved to produce caffeine. This evolution took place though in three lineages that are spaced very far apart in terms of years with other lineages in between them, and being more closely related to each, that have not evolved to produce caffeine. And you can see how far back closest ancestor for all three species is, denoted by the pink dot.

4. These two distant related organisms could have developed this convergent feature because of predators in their environments. Caffeine production might have been something that was toxic to the plants' natural predators and therefore this feature kept the species alive and able to reproduce. Or maybe caffeine production was a way to attract a certain type of pollinator, which aided in reproduction.