Abstract:
Fifteen years into sequencing entire plant genomes, more than
30 paleopolyploidy events could be mapped on the tree of
flowering plants (and many more when also transcriptome data
sets are considered). While some genome duplications are very
old and have occurred early in the evolution of dicots and
monocots, or even before, others are more recent and seem to
have occurred independently in many different plant lineages.
Strikingly, a majority of these duplications date somewhere
between 55 and 75 million years ago (mya), and thus likely
correlate with the K/Pg boundary. If true, this would suggest
that plants that had their genome duplicated at that time, had
an increased chance to survive the most recent mass extinction
event, at 66 mya, which wiped out a majority of plant and
animal life, including all non-avian dinosaurs. Here, we review
several processes, both neutral and adaptive, that might
explain the establishment of polyploid plants, following the
K/Pg mass extinction.
