First universal common ancestor

The first universal common ancestor (FUCA) is a proposed non-cellular entity that was the earliest organism with a genetic code capable of biological translation of RNA molecules into peptides to produce proteins.[1][2] Its descendents include the last universal common ancestor (LUCA) and every modern cell.[1][3] FUCA would also be the ancestor of ancient sister lineages of LUCA, none of which have modern descendants, but which are thought to have horizontally transferred some of their genes into the genome of early descendants of LUCA.[3]

FUCA is thought to have been composed of progenotes, proposed ancient biological systems that would have used RNA for their genome and self-replication.[4][5][6] By comparison, LUCA would have had a complex metabolism and a DNA genome with hundreds of genes and gene families.[1]

  1. ^ a b c Prosdocimi, Francisco; José, Marco V.; de Farias, Sávio Torres (2019), Pontarotti, Pierre (ed.), "The First Universal Common Ancestor (FUCA) as the Earliest Ancestor of LUCA's (Last UCA) Lineage", Evolution, Origin of Life, Concepts and Methods, Cham: Springer International Publishing, pp. 43–54, doi:10.1007/978-3-030-30363-1_3, ISBN 978-3-030-30363-1, S2CID 199534387, archived from the original on 2022-06-29, retrieved 2023-11-02
  2. ^ Cite error: The named reference :3 was invoked but never defined (see the help page).
  3. ^ a b Harris, Hugh M. B.; Hill, Colin (2021). "A Place for Viruses on the Tree of Life". Frontiers in Microbiology. 11. doi:10.3389/fmicb.2020.604048. ISSN 1664-302X. PMC 7840587. PMID 33519747.
  4. ^ Cite error: The named reference :2 was invoked but never defined (see the help page).
  5. ^ Cite error: The named reference :4 was invoked but never defined (see the help page).
  6. ^ Cite error: The named reference NLane_Funke was invoked but never defined (see the help page).