A Partial Solution to the C-Value Paradox

In the half-century since the C-value paradox (the apparent lack of correlation between organismal genome size and morphological complexity) was described, there have been no explicit statistical comparisons between measures of genome size and organism complexity. It is reported here that there are significant positive correlations between measures of genome size and complexity with measures of non-hierarchical morphological complexity in 139 prokaryotic and eukaryotic organisms with sequenced genomes. These correlations are robust to correction for phylogenetic history by independent contrasts, and are largely unaffected by the choice of data set for phylogenetic reconstruction. These results suggest that the C-value paradox may be more apparent than real, at least for organisms with relatively small genomes like those considered here. A complete resolution of the C-value paradox will require the consideration and inclusion of organisms with large genomes into analyses like those presented here.