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Department of Biological Sciences

Dr. Ward Watt contributed to a new study published in Science Advances

Species vary in their phenotypes, allocating resources in differing amounts to growth, maintenance, and reproduction in an attempt to maximize fitness. Across the tree of life, individuals within species also vary in these life history traits. When genetically regulated and causing distinct phenotypes, these intraspecific polymorphisms are called alternative life history strategies (ALHS). Understanding the evolutionary origins and factors maintaining alternative life history strategies (ALHS) within species is a major goal of evolutionary research. Butterflies in the genus Colias are characterized by their yellow, orange, or red wing coloration. However, at least a third of the approximately 90 Colias species have a female-limited ALHS called Alba, where female wings are white. In their last study titled "Evidence for a single, ancient origin of a genus-wide alternative life history strategy", Dr. Ward Watt and his colleagues used comparative genome-wide association study and population genomic analyses to analyze Alba and found that Alba evolved once near the base of the genus and has been subsequently maintained via introgression and balancing selection. They further identified and validated a cis-regulatory region of Alba, which likely acts as a modular enhancer for the induction of the Alba ALHS. 

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