Abstract:
Polyploidy may provide adaptive advantages and is considered
to be important for evolution and speciation. Polyploidy events
are found throughout the evolutionary history of plants,
however they do not seem to be uniformly distributed along the
time axis. For example, many of the detected ancient wholegenome
duplications (WGDs) seem to cluster around the K/Pg
boundary ( 66 Mya), which corresponds to a drastic climate
change event and a mass extinction. Here, we discuss
more recent polyploidy events using Arabidopsis as the most
developed plant model at the level of the entire genus. We
review the history of the origin of allotetraploid species
A. suecica and A. kamchatica, and tetraploid lineages of
A. lyrata, A. arenosa and A. thaliana, and discuss potential
adaptive advantages. Also, we highlight an association
between recent glacial maxima and estimated times of origins
of polyploidy in Arabidopsis. Such association might further
support a link between polyploidy and environmental
challenge, which has been observed now for different timescales
and for both ancient and recent polyploids.
