Rails, rails, and rails at the Natural History Muesum

I started my Marie Skłodowska-Curie fellowship at the Natural History Museum in London/Tring three days ago, and have been busy with paperwork, introductions, meeting lovely new people, and being awestruck but the magnificent buildings, history, and collections. Here, I will spend the coming couple of years investigating the genomic underpinnings of the convergent evolution of flight loss in island rails.

Today, I had the privilege of looking at one of these rails that have not quite lost its flight ability yet, but is somewhere along the trajectory: a Galápagos Rail Laterallus spilonota collected by Charles Darwin himself. The timing could not have been better, as this was the same day that a new preprint came out on bioRxiv about the evolutionary history of the Galápagos Rail!

I have been lucky enough to join a collaboration headed by Jaime Chaves at SFSU, where I helped assemble mitochondrial genomes from century-old specimens from the California Academy of Sciences, and then used those for phylogenetic analyses. We confirm that the Galápagos Rail is the sister of the Black Rail L. jamaicensis on mainland North and South America, and that it colonized the Galápagos Islands about 1.2 million years ago. Sanger sequencing three genetic loci in modern samples shows that present-day populations on different islands display low genetic diversity, and somewhat surprisingly are not differentiated, indicating ongoing gene flow. So perhaps the Galápagos Rails still use their wings after all!

Part of Figure 1a from Chaves et al. (2020) shows a dated phylogeny based on mitochondrial genomes. Here, the Galápagos Rail Laterallus spilonota comes out as a sister to the Inaccessible Island Rail L. (formerly Atlantisia) rogersi, simply because the no mitochondrial genomes have been sequenced for the two other species in the clade—Black Rail L. jamaicensis and Dot-winged Crake L. (formerly Porzana) spiloptera. The illustrations in the figure from Chaves et al. (2020) is reproduced with permission from Lynx Edicions ©.

This is a great way to start on the collaboration with Jaime, who will continue to be involved in my FLIGHTLOSS project.

Read more about the Galápagos Rails at bioRxiv.