From Newsgroup: talk.origins

https://www.sciencedaily.com/releases/2026/02/260210082913.htm

https://www.cell.com/cell-genomics/fulltext/S2666-979X(26)00002-9

Previous research estimated when LUCA existed using genes common to all lifeforms (archaea and eubacteria). Eukaryotes evolved later within the Archaea lineage. This study looked at genes that had already duplicated before LUCA existed, so they give a view of gene evolution as the LUCA
genome evolved. They are only looking at what existed after the genetic
code evolved, and these might have been among the early genes that
evolved when the LUCA genome was evolving. The last paper put up on TO
that determined that LUCA likely existed 4.2 billion years ago noted
that by this time bacteria had evolved the double membrane, and had
genes needed to be chemotrophes and photosynthetic bacteria. This just
means that LUCA was already a highly evolved organism, but it is as far
back as we can go in terms of dealing with extant lifeforms. Looking at
genes that duplicated before LUCA existed is a way to look back to when
the LUCA genome was evolving, but it can't tell us what the lifeforms
that existed before the genetic code were like. We might propose that
these early genes were replacing functions that were already being
performed by non DNA encoded protein functional units. It is likely the
only means we have of trying to figure out what life was like before the genetic code evolved.

Ron Okimoto

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