A interactive map with that info would be awesome!

> Capsaicin, the compound that makes chili peppers hot is an evolutionary filter designed to punish mammals and reward birds.

This is an outdated assumption, with no data behind it. (Yes, birds are immune, but that's not enough to prove this is why peppers evolved capsaicin, and in high levels.)

Capsaicin is a fungicide, and a survey showed that Scoville Heat Units (SHU), a measure of how much capsaicin is in a pepper (or hot sauce), varied quite reliably with local levels of a wild fungus that plagues pepper plants.

Surviving infection is far more important than selecting for slightly better distributors of the seeds.