persisted as one of the potential candidates for the initial steps in assembling beings
using energy from simple reactions to sustain themselves, self-reproducing entities,
something alive. Current origin-of-life theories classify in two main groups:
“information first”, usually based on recent discoveries that RNA can both carry
genetic information and act enzymatically (early life as an “RNA world”), and
“energy transduction first” leading to an enzyme system somewhat akin to
mitochondrial electron transfer. In the latter, given production of a molecular “energy
currency” like ATP, perhaps many things eventually become possible. Both schemes
usually invoke formation of vesicles (“protocells”) by fatty acids emulsifying in water
capable of containing suites of “prebiotic” reactions. Proponents of both starting
points have come in recent speculations to suppose that the elevated temperature and
possibly the clay and pyrite or calcite surface chemistries of hydrothermal vents could
be part of the process of “abiogenesis”.
(^) Dyson (1999) suggested that reproducing, protein-based metabolic systems and
nucleic-acid-based replication systems developed separately, possibly at different
sites, and later coalesced to provide reproduction with an exact replication
mechanism. Their coalescence would carry back to an earlier stage the theme of
evolution through symbiotic combinations that gave the eukaryotes mitochondria and
chloroplasts. This has at least esthetic appeal.
(^) Even a fully elaborated scheme for de novo synthesis of living systems will require
a leap of faith to qualify as the accepted story of the origin of life on Earth (or even
elsewhere). The best we can hope for is a rational scheme, possibly one duplicated in
the laboratory. That story, if it is ever developed, would become part (with the Big
Bang, a theory for consciousness and other components) of our scientific origin myth.
We leave this topic at that, but provide a few references for those interested: Budin et
al. (2009); Budin & Szostak (2010); Lane et al. (2010); Shrum et al. (2010). These
recent papers suggest that deep vents heated by serpentinization and sustaining
alkaline pH have substantial potential for installing functions in life-initiating
protocells.
(^) Sarah Hoffman published important studies in several areas of oceanography and
geology. She died in late 2010, succumbing to long-fought bone cancer. Jack Corliss
was dismissed by his university for not publishing sufficiently. Two of the most
important discoveries (and papers) in the history of science were not enough. He
moved to Hungary, where he is still thinking important thoughts.