"Tree of Life Turns Out to Have Surprisingly Complex Roots"
An article about investigations into the common ancestor of
all life. One thing which interested me:
"A new and far-reaching theory about the universal ancestor
has been developed by Dr. Woese. Though he declined to discuss
it because his article is due to be published, in the Proceedings
of the [USA] National Academy of Sciences, colleages said the
theory envisages all three kingdoms [that is, not kingdoms, but
the domains bacteria, archaea and eukarya] emerging independently
from a common pool of genes. The pool was formed by a community
of cells that frequently exchanged genes by lateral transfer."
Tom Scharle scha...@nd.edu "standard disclaimer"
Some of the more masochistic readers might recall a debate between Steve
LaBonne and me from 1995. We were discussing Woese's Three Domain
Hypothesis and I was pointing out the flaws to Steve (unsuccessfully).
I bet him that Woese would abandon the Three Domain Hypothesis by
January 1997. I lost the bet (a case of Canadian beer).
I'm glad to see that Woese is finally beginning to see the light.
The idea that the earliest organisms may be the result of fusions and
mixing of genes has been around for a decade. Recent examples of such
speculations can be found in,
Koonin et al. (1997) Comparison of archael and bacterial
genomes: computer analysis of protein sequences predicts
novel functions and suggests a chimeric origin for the archaea.
Molec. Microbiol. 25, 619-637.
Forterre, P. (1997) Archaea: what can we learn from their
sequences? Curr. Opinion in Genet. Devel. 7, 764-770.