Monday, July 9, 2012
Amphibians live in two worlds. One is wet and reminiscent of the sea, the other is dry and novel and full of new possibilities. It takes a little of both to survive. A frog's skin has to stay wet so it can exchange gases while on land. But it can't sing underwater. This treefrog seemed to be defying common sense by resting on a dry leaf in Sequatchie Cove during a drought.
Just feet away, Bill Keener spoke about how a farmer can stay alive in the modern world by borrowing ecological tactics from the past. The frog might have been there to listen. This species is grey as an adult, but can stay green for months after emerging from its tadpole puddle. On such a hot day, the frog seemed an improbable bleb of vulnerable color in the wilting underbrush.
But amphibians really do live two worlds. After climbing through this maze of garden variety wonders, it will need to return to water, where it first grew legs. Our vertebrate ontogeny does recapitulate phylogeny in some ways. If you cram a person underwater, they drown. But all of us lived in a watery capsule for the first 9 months of our lives.
Soon after taking this picture, I returned to the air conditioned office to finish an infomercial.