EARSHOT Evolution of the Auditory Region Structures of the Extinct Ruminant Hoplitomeryx

Dr. Robson started EARSHOT, their Marie Skłodowska-Curie Actions postdoc, in October 2026. Working with Dr. Alexandra van der Geer, they are investigating how long-term island isolation affects the ear region in ruminants (e.g., cows, deer, sheep). 

EARSHOT focuses on a unique record, the species radiation of the endemic ruminant genus Hoplitomeryx on the palaeoisland of Gargano (Italy). Islands are natural laboratories for evolution, particularly for groups that radiated in the absence of competitors to fill a variety of niches. Like many island endemics, Hoplitomeryx had a large range of body sizes, from a short-limbed fox-sized species to a giant species with long limbs like those of a camel. While these extreme size differences could explain some of the variation in the ear region among species, it does not explain the high variation within species. The variation within Hoplitomeryx raises the fundamental question of whether the ear region has a consistent slow rate of evolution, or if it may be accelerated in some groups, affecting our understanding of evolutionary relationships. In addition, the potential extreme variation in the ear region of endemic taxa highlights a major gap in our understanding of the effects long-term isolation has on evolution, an increasingly important topic given ongoing habitat fragmentation resulting in isolated ecological islands.