10.5061/DRYAD.8262
Galván, Ismael
Spanish National Research Council
Møller, Anders P.
French National Centre for Scientific Research
Data from: Brain size and the expression of pheomelanin-based colour in birds
Dryad
dataset
2011
Comparative studies
2011-01-06T13:55:26Z
2011-01-06T13:55:26Z
en
https://doi.org/10.1111/j.1420-9101.2011.02232.x
338677 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Eumelanin and pheomelanin are the most common vertebrate pigments. They
generate different colours and are synthesized under different
physiological conditions. While pheomelanogenesis requires high levels of
a key intracellular antioxidant (glutathione, GSH), eumelanogenesis is
inhibited by GSH. This implies that species that present the molecular
basis to produce large amounts of pheomelanin might be more limited to
perform other costly processes that generate oxidative stress than species
that produce eumelanin. Brain development requires large amounts of energy
and antioxidants during ontogeny, so that large-brained species may be
constrained in their simultaneous synthesis of large amounts of
pheomelanin, but not in their synthesis of eumelanin. Here we tested this
hypothesis in a large dataset of 323 bird species. After controlling for
the effects of phylogeny, latitude and sexual dichromatism, the proportion
of pheomelanic plumage colour was strongly negatively related to the
relative brain mass of species, while no relationship was found for the
proportion of eumelanic colour. This indicates that the production of
pheomelanin is a costly process that cannot evolve together with complex
neural structures and thus with large cognitive capacity. This is the
first time that the expression of melanic traits is found to correlate
with another phenotypic character across species.
Appendix S1Body mass (g), brain mass (g), eumelanic and pheomelanic
plumage colour score, mean breeding latitude (ºN) and sexual dichromatism
in melanin-based color (0: monochromatic, 1: dichromatic) for the 323
species of birds used in the study.Appendix S2Phylogenetic hypothesis used
in the study.