Brain size is associated with a greater ability to survive in changing environments. A bigger brain also brings a greater capacity for innovation and behavioral flexibility, allowing you to face new challenges. This may suggest that environmental disturbances humans are causing, including global warming and habitat loss, would favor larger-brained species. However, this is not so. On the contrary, a larger brain indirectly carries a greater risk of extinction among mammals: the high energy expenditure required for its maintenance limits the reproductive response capacity to environmental changes, The study relates the size of the brain of a large number of mammals with their degree of threat according to the Anguilla Email List International Union for Conservation of Nature. “Of course, bigger animals have bigger brains,
but when studying brain size in relation to body size we have observed that a relationship is found contrary to that suggested by previous studies: a greater relative size of the brain is associated with a greater risk of extinction ”, explains Eloy Revilla, CSIC researcher at the Doñana Biological Station. “However, this relationship between brain size and degree of threat is not direct. It’s not that animals with bigger brains are more persecuted or respond worse to environmental changes, ”says Revilla. “What happens is that the brain is a very expensive organ to maintain. In humans, the brain represents 2% of body mass, but consumes 20% of energy. The larger size of the brain leads to additional costs that impact many characteristics of the life of the species and delay their development: the gestation period is lengthened,
weaning is delayed and, therefore, the period of dependence on the mother is increased and litters are less numerous. All this makes their energy requirements more difficult to satisfy and their demographic response capacity to environmental changes is limited ”, “To verify the observed patterns, we have repeated the analyzes for the groups for which the greatest amount of information was available, carnivores, artiodactyls and primates, and the observed pattern was practically the same in all cases”, indicates the researcher. “These results suggest that under current conditions, the restrictions imposed by brain size outweigh its potential benefits. Thus, human activities may be changing the selective forces that for millions of years have been leading to a tendency to increase the size of the brain ”, concludes Revilla.