Re: The Great Filter

Crosby_M (
Wed, 04 Sep 96 17:21:00 EDT

It looks like Sean Morgan beat me in pointing out that the Great Filter
debate about the evolution of life on Earth is missing an important piece of
the puzzle:

>The jumps seem to be Prokarya to Archaea to Eukarya.

I might also suggest the following:

The Science news article notes:

"In 1977, Carl R. Woese of the University of Illinois at Urbana-Champaign
shook this tree of life when he declared that several known microorganisms
deserve a branch of their own [Archaea - the autotrophs]."

"Autotrophs, unlike animals, do not depend upon amino acids and organic
molecules from their environment. M. jannaschii 'makes everything it needs
from carbon dioxide, nitrogen, and hydrogen,' says Venter [J. Craig Venter
of The Institute for Genomic Research ] ... [Recently] investigators have
discovered abundant archaea all around them. 'It shows how little we know
about life on this planet. This group of organisms could represent more than
50 percent of the earth's biomass,' says Venter"

"Understanding how and when autotrophs evolved may topple the popular idea
that life originated in a primordial pool rich in amino acids and organic
molecules. 'That theory has been challenged, especially in recent years, by
scientists, including myself, who believe life began in an autotrophic way,'
says Woese. "

Mark Crosby