Predicting Existence

This is somewhat off-topic or off-trend - well, different. I've seen this story a number of times in different ways, but it has always struck me that when you have a theory that allows you to make specific predictions that are ultimately proven correct, even more than 40 years later, you've got a pretty powerful tool.

Short version - after examining a very unique species of orchid, Mr. Darwin predicted that a very unique species of moth must exist in order to propigate the orchid species - and guess what - 41 years later someone found it.

The moth Xanthopan morgani praedicta and the star orchid Angraecum sesquipedale