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SUMMARY:Steven Benner: How life could not NOT originate on rocky planets\,
  Earth\, Mars\, and 100 billion others in the Milky Way Galaxy - Steven Be
 nner (FfAME Distinguished Fellow)
DTSTART:20250506T100000Z
DTEND:20250506T110000Z
UID:TALK229876@talks.cam.ac.uk
CONTACT:Paul B. Rimmer
DESCRIPTION:In Person\n\nPrebiotic chemistry these days on Earth operates 
 on two different metaphorical "worlds". On one\, leading with the elegant 
 work of the Sutherland\, Simons\, and Leverhulme teams\, the focus is on s
 urface photochemistry of molecules arising from hazy reduced atmospheres\,
  in particular\, those where nitrogen is at the oxidation level of ammonia
 . It has not (yet) produced a single molecule of RNA\, the (proposed) info
 rmational molecule that (purportedly) initiated Darwinian evolution.\n\nIn
  this talk\, a visitor from the other world will show how oligomeric RNA w
 ith 3'\,5'-linkages 150 ± 50 nucleotides long forms as the natural outcom
 e of "privileged" chemistry beneath redox neutral atmospheres that are tra
 nsiently reduced by Vesta-to-Ceres sized impactors. On Earth\, this most l
 ikely happened 4.30 ± 0.05 billion years ago.\n\nThis RNA is long enough\
 , and stereoregular enough\, to have provided catalysts to support an "RNA
  World". This World invented protein translation 4.20 ±0.11 billion years
  ago (based on arguable molecular clocks)\, and was sufficiently widesprea
 d to have left isotope enriched carbon entrapped in zircons dated at 4.10 
 billion years ago.\n\nThe production of pentoses (like ribose\, ~100 kg/km
 2 per year ) cannot NOT happen on such worlds\, if covered by basalts that
  deliver borate and condensed polyphosphates. Borate and condensed polypho
 sphate likewise privilege post-impact steps that yield ribonucleosides\, r
 ibonucleotides\, and RNA.
LOCATION:East Seminar Room\, Ray Dolby Centre
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