Eyespot Caterpillar

Natural Selection and the Owl Butterfly

In the first tutorial on evolution,I gave the example of the peppered moth during theIndustrial Revolution in England and how, before theIndustrial Revolution, there were a bunch of moths: some weredark, some were light, some were in between. But then once everything becamesoot filled, all of a sudden, the dark moths were lesslikely to be caught by

predators and so all of thewhite moths were less likely to be able to reproducesuccessfully, so the black moth trait, or that variant,dominated. And then if you came a littlebit later and you saw all the moths had turned black,you'd say all these moths are geniuses. They appear to have somehowengineered their way to stay camouflaged.

And the point I was makingthere is that, look, that wasn't engineered or an explicitmove on the part of the moths or the DNA, that wasjust a natural byproduct of them having some variation, andsome of that variation was selected for. So that example, that was prettysimple: black or white. But what about more complicatedthingsé So, for example, here I've got acouple of pictures of what's

commonly called theowl butterfly. And what's amazing here, andit's pretty obvious, as I probably don't have to point outto you, is its wing looks like half of an owl's eye. I can almost draw a beak hereand draw another wing there and you can imagine an owlstaring at us, righté And here, too, I could imaginea beak here and you would think an owl there, too.

And so the question is how doessomething this good show up randomly, righté I mean, you could imagine, OK,little spots or black and white or grey, but how doessomething that looks so much like an eye generate randomlyé Now the answer is well,there's a couple of answers. One is why does this eyeexist, or this eyelike pattern or this owllikeeye's patterné

And there, the jury'sstill out on that. I read a little bit about it onWikipedia and all of these images I got from Wikipedia. In Wikipedia, they said,look, there's two competing theories here. One theory is that this, eventhough to us humans, the way we see things, it looks likean owl's eye, that this is actually a decoy.

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