Saturday, February 13, 2010

Pitching woo

A week or two ago I wrote about Ursula Goodenough, microbiologist and religious naturalist. As you may have noticed, she came across the post and responded in Comments.

I went to her website at Washington University in St. Louis to see what she is up to these days -- and there saw this microphotograph of two Chlamydomonas reinhardtii gametes mating.

Chlamydomonas is a kind of green alga that swims with two little whiplike tails. Haploid gametes of C. reinhardtii come in two types, called mt(+) and mt(-).

Now I don't want to be cutsie or coy, but there was something tender and sexy about the scene, and maybe I even felt a bit voyeuristic looking in on these unicell lovers engaging in foreplay with their fluttering flagella. Was it just the approach of Valentine's Day that put my heart into the mood to see romance where nothing is at work but chemical reactions? Or is what we call romance among humans itself just a highly evolved embellishment of what these two algae are up to on their bower bed of agar?

Certainly, these two microbes seem to know what they are doing, so intent are they on fusing their genes. Tristan and Isolde. Heloise and Abelard. Romeo and Juliet. But soft, what light through yonder petri dish breaks. It is the east, and mt(-) is the sun.

Or is it mt(+)?

Never mind. Leave them to their dalliance. Tomorrow is Valentine's Day and we have our own entanglements to think about. Presumably, mt(+) and mt(-) find each other with some sort of chemical signal -- a come-hither molecule that binds on a receptor. As Goodenough writes in The Sacred Depths of Nature:
Animals with nervous systems take the behavioral possibilities for sexual attraction to every possible limit. Fireflies pulse, houseflies beat their wings, moths send out musk, fish dance, frogs croon, birds display feathers and song, mammals strut and preen. If this is a planet shimmering with awareness, then a great deal of that awareness is focussed on the sexual signals that creatures send to one another.
Have you bought that box of chocolates?