Excerpt

The noted contemporary paleontologist and natural historian Steven Jay Gould has said of the history of life that “any replay of the tape would lead evolution down a pathway radically different from the road actually taken” (Gould 1989, 50). Should one make such a strong statement about all aspects of life, though? Gould studied the body plans of the major groups of animals that suddenly appeared in the fossil record 570 million years ago, in a period called the Cambrian explosion. Indeed, it seems largely accidental that just this combination should have come to make up the entire animal world, creating a large-scale taxonomy of which only a subpart has survived to this day.

But what about the chemical composition of those organisms, or the way they capture energy to maintain and replace themselves, which we also share? Could that really have taken a different form than the one we see attested today? What about the great events when biological innovations changed the surface chemistry of the earth, like the emergence of photosynthesis that loaded our atmosphere with molecular oxygen, after two billion years in which it had had very little? What of endosymbiosis, when one group of bacteria-like unicells began living as organelles within another? How much of chance is there in these stages of our shared structure and history, and how much of necessity?

For five weeks in the summer of 2003, a diverse group led by Science Board member Harold Morowitz, postdoctoral fellow Jennifer Dunne, and research professor D. Eric Smith met to examine some of the universal structures and patterns in living systems, from biochemistry to ecology, and to ask which might have arisen from the action of underlying “laws of life.” The goal was a set of rules or principles that select living forms from chemistry and geophysics, the way simple rules such as the Pauli exclusion principle generate the periodic table of the elements, and all of chemistry, from a few properties of the proton, neutron, and electron.

BACK TO Worlds Hidden in Plain Sight