Convergent Regulatory Evolution and Loss of Flight in Paleognathous Birds

April 5, 2019
southern cassowary Luke Seitz

Species from widely divergent taxa can experience similar changes in traits. What underlying genetic drivers cause these parallel changes remains an open question. Scott Edwards, Tim Sackton (Director of Bioinformatics and former Postdoc) and PhD student Phil Grayson used a new method developed by collaborators in the Harvard Statistics Department to look across groups of birds that have repeatedly lost flight. The team showed there is convergence in the regulatory regions associated with genes related to flight, but not within the protein coding regions.

In the study, published in Science, researchers used a process that aligned the genomes of more than three dozen bird species - both flying and flightless - and found the regulatory regions appear to play a key role in the body-scaling changes that go along with flight loss. The relationships among these birds imply at least three (and probably more) independent losses of flight. The study was covered by The Harvard Gazette.

Image of southern cassowary by Luke Seitz