Data from: Weak sperm differentiation in Darwin's finches

The submission contains data sets from a study of sperm evolution in eight
species of Darwin's finches from two islands in the Galapagos
archipelago. The data sets comprise morphological measurements, sperm size
measurements, and genome-wide Single-Nucleotide-Polymorphisms (SNPs). The
morphological measurements were used for species confirmation. Sperm size
differentiation was analysed in a phylogenetic context where a
time-calibrated phylogeny for the species were constructed based on SNP
data. The sperm size data were also used to infer the frequency of
extrapair paternity. The results indicate that sperm size evolves much
more slowly than beak and body size in this radiation, and similar to
other songbirds with moderate-to-low levels of extrapair
paternity.