Friday, October 21, 2016

A DNA barcode for an extinct species

The sunset moth (Urania sloanus) from Jamaica has been last seen around 1895. This spectacular moths went extinct in the mid-1890s or the very early 1900s.  It was first described by Pieter Cramer, a Dutch merchant and entomologist in 1779. The species name honours Sir Hans Sloane (1660–1753), who served as physician to Jamaica's Lieutenant Governor in 1687-88 and whose collection of plant and animal specimens became the foundation of the British Museum. The genus name Urania derives from Ancient Greek Ουρανία, one of the Muses, and means literally 'The Heavenly One'.

There are only a few specimens preserved in the most prestigious world collections, and there was one offered on eBay a few years ago and a former colleague of mine actually bought it with the help of the entire Augusta campus of the University of Alberta.

What we did not have so far was a DNA barcode of this species but that has changed now. Using High-throughput sequencing (HTS) technology colleagues from our institute and the Canadian National Collection of Insects were able to provide a full-length barcode sequence for this extinct beauty. They used a HTS protocol developed specifically for museum type specimens. This new sequence allowed them to make a phylogenetic placement of the species and this in turn has some important implications which the authors explain in their conclusion:

Despite the complex and much debated geological history of the Caribbean, the evolution of Urania in the region seems relatively recent and mostly based on dispersal and subsequent isolation. Island biogeographic theory predicts that most island species are likely to be recent derivatives from mainland populations, and with some exceptions, islands (particularly small islands, here not the case for Cuba) tend to be home not to ancient endemics, but rather to recent offshoots from mainland progenitors. This has important implications for conservation biology, considering that many island populations are threatened.While the loss of island lineages is regrettable, it is important to recognize that closely allied populations often occur on neighbouring mainlands. Understanding the evolutionary relationships between island species and their mainland counterparts is thus a key consideration in island conservation efforts.

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