Artificial selection for large and small relative brain size in guppies (Poecilia reticulata) results in differences in cognitive ability
Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
Vertebrate brain size is remarkably variable at all taxonomic levels. Brains of mammals forexample, range from 0.1 gram in small bats (Chiroptera) to about 8-9 kilos in Sperm whales(Physeter macrocephalus). But what does this variation in size really mean? The link between brainsize and cognition is debated due to, for instance the difficulties of comparing cognitive ability indifferent species. A large number of comparative studies continue to provide information aboutcorrelations found both within and between species. The relative size of the brain is an example of apopular measurement that correlates with cognitive ability. But to date, no experimental studieshave yielded any proof causality between relative brain size and cognitive ability. Here I usedguppies selected for either large or small relative brain size to investigate differences in cognitiveperformance of a quantity discrimination task. The results from this experiment provideexperimental evidence that relative brain size is important for cognitive ability, and that a differencein cognitive ability could be obtained already after two generations of selection experiments onrelative brain size in a vertebrate.
Place, publisher, year, edition, pages
2012. , 15 p.
cognition, guppy, artificial selection, brain size
IdentifiersURN: urn:nbn:se:uu:diva-192953OAI: oai:DiVA.org:uu-192953DiVA: diva2:600822
Bachelor Programme in Biology / Molecular Biology
UppsokLife Earth Science
Kolm, Niclas, Assistant ProfessorKotrschal, Alexander, Doctor
Brunberg, Anna-Kristina, Associate Professor
ProjectsArtiﬁcial Selection on Relative Brain Size in the Guppy Reveals Costs and benefits of Evolving a Larger Brain