xkcd #3221: Landscape Features
Title text:
'Well, there's speculation that it's due to a mantle hotspot.' --a geologist who's trying to cover up the fact that they didn't hear your question
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3221/
Passenger pigeons were responsible for the growth of America's forest before we cut down all the trees and ate the birds into extinction.