1 Citation 236 Views 44 Downloads
Extreme environmental perturbations are rare, but may have important
evolutionary consequences. Responses to current perturbations may provide
important information about the ability of living organisms to cope with
similar conditions in the evolutionary past. Radioactive contamination
from Chernobyl constitutes one such extreme perturbation, with significant
but highly variable impact on local population density and mutation rates
of different species of animals and plants. We explicitly tested the
hypothesis that species with strong impacts of radiation on abundance were
those with high rates of historical mutation accumulation as reflected by
cytochrome b mitochondrial DNA base pair substitution rates during past
environmental perturbations. Using a dataset of 32 species of birds we
show higher historical mitochondrial substitution rates in species with
the strongest negative impact of local levels of radiation on local
population density. These effects were robust to different estimates of
impact of radiation on abundance, weighting of estimates of abundance by
sample size, statistical control for similarity in the response among
species due to common phylogenetic descent, and effects of population size
and longevity. Therefore, species that respond strongly to the impact of
radiation from Chernobyl are also the species that in the past have been
most susceptible to factors that have caused high substitution rates in
mitochondrial DNA.
236 views reported since publication in 2010.