Baidarka

I think that the example of the Heike Crabs with samurai faces on their shells provides a charming and convincing illustration of evolution. The basic theory is that the faces developed by collective artistic selection by the fisherman. The inferior examples were always eaten and the best examples were thrown back to breed. I consider this to be a form of natural selection even though it is dependent on human intervention since I consider humans to be natural.

I think that this powerful and easy to understand example showing the plasticity of living forms and the mechanism of natural selection would be a great example to use when debating creationists.

Does anyone know where I can find good photos of these remarkable creatures?

pz

One problem: there's no evidence that the appearance of the crab's back is the product of this selection. It has been claimed that they've been shaped by years of these fishermen's work, but we don't know what the original population looked like.

Actually, I find the whole story extremely dubious.

Oolon Colluphid

That was the most annoying thing about Carl Sagan's otherwise marvellous Cosmos series, that he used these crabs as a main example of evolution. Powerful in concept, and bugger all use when related to reality. But then, reality is always rather messier than theory ...

DT

lpetrich

Sagan ought to have done what Darwin had done: discuss some domestic species. Darwin had begun his magnum opus with a detailed discussion of pigeon breeding and some odd-looking breeds that have resulted.

One good example would have been dogs. There is an enormous variety of breeds of them, with a great variety of sizes and shapes and colors -- which had never existed in the wild. And Sagan could have noticed how some dogs are more wolflike than others -- German shepherds and huskies seems to me to be rather wolflike in appearance.

He could have gone on from there to comparative anatomy, perhaps doing a lot of X-raying to reveal internal details.