2021/03/31 by Orlin S. Todorov, Simon P. Blomberg, Anjali Goswami +4 · 1 citation
Earth and Planetary Sciences · Environmental Science · Agricultural and Biological Sciences · #Evolution and Paleontology Studies #Wildlife Ecology and Conservation #Bat Biology and Ecology Studies
paper · doi:10.1098/rspb.2021.0394
openalex publication_date 2021/03/31 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
Considerable controversy exists about which hypotheses and variables best explain mammalian brain size variation. We use a new, high-coverage dataset of marsupial brain and body sizes, and the first phylogenetically imputed full datasets of 16 predictor variables, to model the prevalent hypotheses explaining brain size evolution using phylogenetically corrected Bayesian generalized linear mixed-effects modelling. Despite this comprehensive analysis, litter size emerges as the only significant predictor. Marsupials differ from the more frequently studied placentals in displaying a much lower diversity of reproductive traits, which are known to interact extensively with many behavioural and ecological predictors of brain size. Our results therefore suggest that studies of relative brain size evolution in placental mammals may require targeted co-analysis or adjustment of reproductive parameters like litter size, weaning age or gestation length. This supports suggestions that significant associations between behavioural or ecological variables with relative brain size may be due to a confounding influence of the extensive reproductive diversity of placental mammals.