GELIFES Seminars - Alexander Kotrschal

Alexander Kotrschal (WUR)

The evolution of brains and cognitive abilities

The large variation in brain size that exists in the animal kingdom has been suggested to have evolved through the balance between selective advantages of greater cognitive ability and the prohibitively high energy demands of a larger brain. Despite over a century of research on the evolution of brain size, empirical support for the trade-off between cognitive ability and energetic costs is based exclusively on correlative evidence, and the theory remains controversial. We therefore performed an artificial selection for large and small brain size relative to body size in the guppy (Poecilia reticulata), in an effort to provide experimental evidence for the costs and benefits of increased brain size. After several generations of selection it was apparent that brain size evolved rapidly in response to divergent selection. We found several cognitive benefits but also a range of energetic costs associated with the evolution of large brain size, and I will give an overview of what those brain size selection lines have revealed over the last 12 years

Biosketch:
Alexander undertook his PhD at Bern University, before moving to Uppsala, Vienna, Stockholm and in 2019 to Wageningen University. His research generally focuses on the mechanisms of cognitive and brain evolution, and his team combines comparative studies, field work and artificial selection techniques. He mostly works with fishes and frogs. A recent focus has been how predation drives cognitive evolution. From the prey’s view with guppies as models, and from the predator’s view using the invasive lionfish.