Data from: Miniaturization, genome size, and biological size in a diverse clade of salamanders

Genome size (C-value) can affect organismal traits across levels of
biological organization, from tissue complexity to metabolism. Neotropical
salamanders show wide variation in genome and body sizes, including
several clades with miniature species. Because miniaturization imposes
strong constraints on morphology and development, and genome size is
strongly correlated with cell size, we hypothesize that body size has
played an important role in the evolution of genome size in bolitoglossine
salamanders. If this hypothesis is correct, then genome size and body size
should be correlated in this group. Using Feulgen Image Analysis
Densitometry (FIAD), we estimated genome sizes for 60 species of
neotropical salamanders. We also estimated the “biological size” of
species by comparing genome size and physical body sizes in a phylogenetic
context. We found a significant correlation between C-value and physical
body size using optimal regression with an Ornstein-Uhlenbeck model, and
report the smallest salamander genome found to date. Our index of
biological size showed that some salamanders with large physical body size
have smaller biological body size than some miniature species, and that
several clades showed patterns of increased or decreased biological size
compared to their physical size. Our results suggest a causal relationship
between physical body size and genome size and show the importance of
considering the impact of both on the biological size of organisms.
Indeed, biological size may be a more appropriate measure than physical
size when considering phenotypic consequences of genome size evolution in
many groups.