The skull of a dog and a 3D model of its brain based on high-resolution CT-scanning. Credit: László Zsolt Garamszegi, Enikő Kubinyi, Kálmán Czeibert, Gergely Nagy, Tibor Csörgő, Niclas Kolm, Evolution of relative brain size in dogs—no effects of selection for breed function, litter size, or longevity, Evolution, Volume 77, Issue 7, July 2023, Pages 1591–1606, 10.1093/evolut/qpad063
A recent study published in Biology Letters challenges the traditional belief that domestication is the main cause of reduced brain size in domesticated animals, particularly dogs.
Using a phylogenetic comparative approach, researchers László Zsolt Garamszegi from the Institute of Ecology and Botany in Hungary and Niclas Kolm from the Department of Zoology at Stockholm University in Sweden, found that domesticated dogs do not have significantly smaller brains relative to their body size compared to other canid species. This suggests that domestication may not have as unique an impact on brain size evolution as previously assumed.
It has long been thought that domestication leads to a decrease in brain size due to reduced selection pressures like the need for foraging, mating competition, and predator avoidance.
This reduction in brain size is believed to be a result of the decreased demand for energetically expensive brain tissue in a domesticated setting. While domesticated dogs do show a considerable decrease in brain size compared to their wild ancestor, the gray wolf, this study aimed to determine if this reduction is exceptional when considering a wider phylogenetic perspective.
Garamszegi and Kolm analyzed brain and body size data for 25 canid species, including ancient dog breeds genetically closer to the original domesticated dog.
Their findings indicated that the decrease in brain size in domesticated dogs is not a unique evolutionary event. The observed brain size in dogs fell within the expected range for most ancient breeds included in the study, suggesting that domestication may not be the sole factor influencing brain size reduction in canids.
2024-08-06 19:15:03
Post from phys.org
