Thursday, February 10, 2005


A story on the BBC web site this morning about the Consortium for the Barcode of Life (CBOL). This international alliance of biologists hopes to sequence a single gene, called cytochrome coxidase I, for as many species as possible. The sequence of chemical units along the DNA double helix will serve as a kind of "barcode" that can then be linked to all other information that has been collected concerning that species.

As I read the story, I was thinking of Steve's beautiful comment of yesterday, the "connectedness" he felt one summer evening on the coast of Maine. For all of its prosaic practicality, the CBOL project is a record of connectedness.

Steve's cytochrome coxidase gene differs from mine by perhaps a single "step" out of 648 on the DNA spiral "staircase." Our sequences differ from a chimpanzee by about 60 "steps." And so on, right through the millions of fruiting twigs on the tree of life.

And here is what's astonishing. An evolutionary tree deduced from the information encoded in this single gene (a tiny snippet of a genome) agrees in almost every particular with the tree of life deduced from anatomical studies by generations of biologists and natural historians.

In her wonder-full book The Sacred Depths of Nature, microbiologist (and non-theist) Ursula Goodenough reminds us that the word religion comes from the Latin religio, to bind together again, and she evokes all of what we share with other creatures, including genes. "We are connected," she writes, "all the way down."