Elucidating the genetic basis of adaptations in natural populations is central to understanding the origins of biological diversity. One issue of particular importance is whether changes in the same genes underlie the independent evolution of similar adaptations in different species. Butterflies display a massive array of wing patterns, but much of this diversity appears to be a result of variations on a conserved developmental ground plan. This collaborative project will characterize the genetic basis of color patterning across Heliconius, Limenitis, and Papilio butterflies using a novel strategy that combines traditional experimental crosses with modern advances in genomics. This approach will allow the researchers to identify the specific genes responsible for wing patterning in each species and directly test the hypothesis that a core set of genes controls wing patterning across all butterflies.
Wing pattern diversity is widespread across the entire butterfly phylogeny, providing an unparalleled opportunity to explore the genetics and evolution of adaptation, patterning, parallelism, and convergence across a group that has been evolving and radiating for 100 million years. This project will significantly expand the current understanding of how chance and constraint interact to generate biological diversity by examining, in an integrated and comprehensive way, how diverse lineages generate similar morphologies in response to similar selective pressures. This project will also have a variety of important broader impacts related to the training of post-doctoral researchers, graduate students, and undergraduate students, as well as scientific outreach aimed at elementary, middle, and high school students.
A central, unanswered question in biology is how adaptive phenotypic evolution occurs at the proximate, genetic level. Wing pattern mimicry in butterflies is a historically significant model for the study of evolution by natural selection, yet we know very little about the functional molecular basis of this phenomenon. Our project characterized and compared the molecular basis of mimicry in three butterfly clades; the genera Heliconius, Limenitis, and Papilio. Our work contributed to identifying the molecular basis of mimicry in all three clades and revealed the extent to which this is conserved over evolutionary time. Furthermore, we were able to identify and compare the mutational origin of similar mimicry phenotypes across clades, as well as identify the molecular genetic basis for supergene mimicry in swallowtail butterflies. The impact of these results extends well-beyond butterflies by providing novel insight into the raw material of adaptive evolution, the evolutionary timescale over which the functional basis of adaptive evolution is conserved, and the evolution of genetic architecture. This grant contributed to the publication of 18 scientific articles, training of multiple post-doctoral and undergraduate researchers, and outreach to students and the general public. Furthermore, this grant provided essential research support as the PI transitioned from post-doctoral researcher to assistant professor and lab PI.
