The Case of a Curiously Isolated and Endangered Butterfly - Dr Zachary MacDonald

Conservation, genomics, and conservation genomics: the case of a curiously isolated and endangered butterfly by Dr. Zachary MacDonald

Description: For decades, a small population of hairstreak butterflies in Waterton Lakes National Park was assumed to be the Half-moon Hairstreak (Satyrium semiluna), even though it occurs more than 400km from the nearest known populations. Using a new chromosome-level reference genome and whole-genome sequencing, we found that this Waterton population is extremely genetically distinct and has likely persisted as a small, isolated lineage for up to about 40,000 years. Our genomic data also suggest a long history of inbreeding and local adaptation, which means “genetic rescue” (introducing conspecific butterflies from other populations to increase genetic diversity) could risk disrupting what has kept this population viable, potentially leading to outbreeding depression. In a follow-up paper, we evaluated the full body of evidence under the general lineage concept of species and proposed that the Waterton population represents a distinct species, which we described as the Curiously Isolated Hairstreak (Satyrium semiluna). This presentation tells this butterfly’s story in full, and aims to present the genomic methods in an accessible way while conveying the remarkable evolutionary history we uncovered.