Data from: Using genomic data to revisit a classic example of reproductive character displacement in Haitian Anolis lizards

The pattern of reproductive character displacement (RCD)—in which traits
associated with reproductive isolation are more different where two
species occur together than where they occur in isolation—is frequently
attributed to reinforcement, a process during which natural selection
acting against maladaptive mating events leads to enhanced prezygotic
isolation between species or incipient species. One of the first studies
of RCD to include molecular genetic data was described 40 years ago in a
complex of Haitian trunk anole lizards using a small number of allozyme
loci. In this example, Anolis caudalis appears to experience divergence in
the color and pattern of an extensible throat fan, or dewlap, in areas of
contact with closely related species at the northern and southern limits
of its range. However, this case study has been largely overlooked for
decades; meanwhile, explanations for geographic variation in dewlap color
and pattern have focused primarily on adaptation to local signalling
environments. We reinvestigate this example using amplified fragment
length polymorphism (AFLP) genome scans, mtDNA sequence data, information
on dewlap phenotypes and GIS data on environmental variation to test the
hypothesis of RCD generated by reinforcement in Haitian trunk anoles.
Together, our phenotypic and genetic results are consistent with RCD at
the southern and northern limits of the range of A. caudalis. We evaluate
the evidence for reinforcement as the explanation for RCD in Haitian trunk
anoles, consider alternative explanations and provide suggestions for
future work on the relationship between dewlap variation and speciation in
Haitian trunk anoles.