Monday, March 21, 2005

Unnatural selection?

Remember the old rhyme: "I never saw a purple cow, and hope I never see one; but I can tell you, anyhow, I'd rather see than be one."


H. halobium may have appeared earlier in the history of life than organisms that use chlorophyl. It is not unreasonable to imagine that they might have remained the chemical template for all successive plant life, in which case even land plants might be purple.

And if plants were purple, then some animals might have evolved purple protective coloration. Hence, purple cows. (wink)