Saturday, February 03, 2007

Darwin's Buckets

Coryanthes is a Central and South American genus of orchids, containing quite a number of species, called the bucket orchids. These complex flowers are a marvel of ingenuity, engineered by... well, you decide. The flowers consist of two wing-like sepals, as seen on the right, and the bucket, on the left. An aromatic wax is produced by the orchid between the sepals, and male bees in the tribe Euglossini (orchid bees) seek this wax; they scrape it off and place it in special pouches on their hind legs... the scent then attracts female bees, and so each species of bee seeks a particular species of coryanthes which has the particular scent that attracts only that species of female bee. Now the complicated part starts... the landing area is slippery, so the bees can easily lose their grip and fall into the bucket part of the flower. The coryanthes constantly drips a watery fluid into the bucket (excess is drained off through the side spout so that the bucket doesn't fill to the brim and allow the bee to escape). There are also down- facing hairs lining the bucket to further prevent the bee from climbing out; there is only one way for the bee to get out...the flower has provided a little step on one side of the bucket, which the bee can climb, and it directs him to a tunnel that leads out of the flower. As the bee wriggles through this tunnel, pollen sacs clamp down on the bee's back, he is held for a short period until the glue dries, then he is released to fly away. If he flies to another flower, and happens to fall in the bucket again, as he crawls out through the second tunnel, the pollen sacs on his back become adherent to the stigma, and the flower is fertilized. So only one species of bee seeks an aromatic wax occurring on only one species of orchid, which attracts only the female bee of his species; he falls in a bucket half-full of water and the flower provides him with a step that leads him into an escape hatch, and then glues pollen sacs to his back; the bee then falls in a second flower's bucket and on his way out the pollen sacs are removed to fertilize the flower. Darwin studied coryanthes extensively, and was quite comfortable that it all fit nicely into his theory of evolution; it may well be that the human mind is just boggled by inconceivable periods of time and chance, but I have always had a problem assigning such cleverness to chance. Even a mind as profound as Einstein's had to say "God doesn't play dice". I do not know whether my mind lacks comprehension of the scale of time and chance involved in evolution, or my soul lacks an element of unquestioning faith; either way, the natural world is marvelous beyond mankind's grasp. I have only contempt for those who are destroying this fragile construct, for their own gain.Posted by Picasa

Comments: Post a Comment

<< Home

This page is powered by Blogger. Isn't yours?