[goatinaboat]

were placed randomly around the world, you'd be correct - but they're not. They're placed near locations

The world’s foremost institute for tropical medicine is in London, England. So that debunks that idea.

[ceejayoz]

I mean, that's a practical side effect of the fact that England owned much of the tropics for a few centuries.

It's further evidence that these things get sited sensibly, not randomly.

[ALittleLight]

Sensibly, yes, but not their location isn't based on geographic proximity but rather what is a sensible location for the group building and staffing the lab.