Peppered Moth.avi

Peppered mothMoth comes in two “versions”:

Pre-Industrial RevolutionThe white peppered moth very commonBlended in well

Lichens, tree branches, rocks

PredatorsBirds ate the mothAny moth that did not blend in very well was

prone to get eaten

Industrial RevolutionGreat deal of smoke and soot released into

atmosphere

No more camouflage Soot settled on rocks,

treesBecame darkerKilled lichens

Peppered moth lacking hiding places

MelanismThe black version of the peppered moth

(previously very, very rare) now had significant advantage

Natural Selection in action!

No humans are selecting for black moths or white moths.

NatureNature is selecting against one or the other!

ResultsThe white-and-black moth went from the majority to the minorityEstimated 99.9% to 2%Black moth went from 0.1% to 98%

All of this in about a 40 year spanVERY fast on a biological timescale!

RecentlyThe US and Europe now have cleaner air

standardsWhat happened to the proportion of

peppered vs. black moths?Now shifted towards light-colored

peppered moths again