T. Ryan Gregory
Genome, in press.
Abstract
Although unrelated to any intuitive notions of organismal
complexity,
haploid genome sizes (“C-values”) are correlated with a variety of
cellular
and organismal parameters in different taxa. In some cases, these
relationships are universal – notably, genome size correlates
positively
with cell size in each of the vertebrate classes. Other
relationships
are apparently relevant only in particular groups. For example,
while
genome size is inversely correlated with metabolic rate in both mammals
and birds, no such relationship is found in amphibians. More
recently,
it has been suggested that developmental rate and/or longevity are
related
to genome size in birds. In the present study, a large dataset
was
used to examine possible relationships between genome size and various
developmental parameters in both birds and mammals. In neither
group
does development appear to be of relevance to genome size evolution
(except
perhaps indirectly in birds via the intermediate of body size and/or
within
the rodents), a situation very different from that found in
amphibians.
These findings make it clear that genome size evolution cannot be
understood
without reference to the particular biology of the organisms under
study.