@article{TheEvolutionary:2328,
      recid = {2328},
      author = {Márquez Pizano, Roberto},
      title = {The Evolutionary, Biogeographic, and Genetic Origin of  Color Pattern Diversity in Phyllobates Poison-Dart Frogs},
      publisher = {University of Chicago},
      school = {Ph.D.},
      address = {2020-06},
      pages = {170},
      abstract = {Chapter 1: Divergence, gene flow, and the origin of  leapfrog geographic distributions: The history of color  pattern variation in Phyllobates poison-dart frogs

My aim  in this chapter was to understand the processes driving the  origin and maintenance of the geographic distribution of  solid-yellow Phyllobates populations in Western Colombia,  especially focusing on divergence and gene flow between  populations. Using a combination of phylogenetic and  spatial population genetic analyses, I characterized the  levels of genetic structure and gene flow, as well as the  evolutionary relationships between populations. I found  high levels of previously unrecognized genetic structure  among populations, as well as an even more dynamic  evolution of solid-yellow color patterns than previously  thought. Furthermore, the data showed a strong signature of  short-range gene flow between neighboring population, but  not between distant populations. This indicates that gene  flow between striped populations may be contributing to  their phenotypic similarity, but the same cannot be said  for solid-yellow ones.

Chapter 2: Disentangling the origin  of a color pattern cline

In this chapter I focused on the  color pattern cline present in the upper San Juan River  drainage (see section 1.1 in pg. 2), which connects two  recently diverged sister species, one of which is striped  and the other solid-yellow. Based on patterns of genetic  and phenotypic variation among populations in this area I  aimed to understand the biogeographic origin of this color  pattern cline. I found patterns consistent with either a  recent parapatric range expansion or relatively old ongoing  hybridization as the processes generating the cline. I  favor the first explanation, as it conforms with our  expectation of strong selection on these frogs’ aposematic  coloration, which have been backed by recent work on  closely related species.

Chapter 3: The genetic basis and  evolutionary history of color pattern variation in  Phyllobates poison frogs

Considering the convergent  evolution of highly similar color patterns in Phyllobates,  which even seem to share a common developmental basis, my  last chapter aimed at identifying genomic regions  associated with color pattern variation and investigating  their evolutionary history to disentangle the genetic  processes underlying this instance of convergent evolution.  Using genome-wide divergence scans and association analyses  I identified several loci associated with color pattern,  out of which four stood out as candidate genes involved in  color pattern differences. Genetic variation at these loci  and their adjacent regions again suggested that  introgression has not played a role in the convergent  evolution of solid yellow coloration, pointing to  independent evolution of these species’ color patterns.},
      url = {http://knowledge.uchicago.edu/record/2328},
      doi = {https://doi.org/10.6082/uchicago.2328},
}