Moorean and Tahitian Partula tree snail survival after a mass extinction: new genomic insights using museum specimens

Natural history museum collections provide a biodiversity window into the past and are of particular importance to the study of extinction-impacted clades such as the Pacific Island tree snail family Partulidae. Deliberate introduction of the predatory rosy wolf snail Euglandina rosea in the late 20th century led to the extinction/extirpation of 55/61 Society Island Partulidae species. In this study, we phylogenomically investigated the inter-relationships of the three surviving Society Island valley Partula species: P. taeniata (Moorea), P. clara and P. hyalina (Tahiti). All three formed a distinct clade in earlier mitochondrial phylogenies. Using Next Generation Sequencing (NGS) double digested Restriction Associated DNA sequencing (ddRADseq), we found that 46-year-old lyophilized museum specimens produced similar numbers of reads, sequencing depth, and loci as 10-year old ethanol-preserved collections. Phylogenomic trees indicated that Tahitian P. clara and P. hyalina are the result ...