Eukaryogenesis, how special really?
Another interesting article.
Another interesting article.
Abstract
Eukaryogenesis
is widely viewed as an improbable evolutionary transition uniquely
affecting the evolution of life on this planet. However, scientific and
popular rhetoric extolling this event as a singularity lacks rigorous
evidential and statistical support. Here, we question several of the
usual claims about the specialness of eukaryogenesis, focusing on both
eukaryogenesis as a process and its outcome, the eukaryotic cell. We
argue in favor of four ideas.
- First, the criteria by which we judge
eukaryogenesis to have required a genuinely unlikely series of events 2
billion years in the making are being eroded by discoveries that fill in
the gaps of the prokaryote:eukaryote “discontinuity.”
- Second,
eukaryogenesis confronts evolutionary theory in ways not different from
other evolutionary transitions in individuality; parallel systems can be
found at several hierarchical levels.
- Third, identifying which of
several complex cellular features confer on eukaryotes a putative richer
evolutionary potential remains an area of speculation: various keys to
success have been proposed and rejected over the five-decade history of
research in this area.
- Fourth, and perhaps most importantly, it is difficult and may be impossible to eliminate eukaryocentric bias from the measures by which eukaryotes as a whole are judged to have achieved greater success than prokaryotes as a whole.
Overall, we question
whether premises of existing theories about the uniqueness of
eukaryogenesis and the greater evolutionary potential of eukaryotes have
been objectively formulated and whether, despite widespread acceptance
that eukaryogenesis was “special,” any such notion has more than
rhetorical value.
Context: reading of David Quammen's "The Tangled Tree: A Radical New History of Life".