The effect of body size evolution and ecology on encephalization in cave bears and extant relatives.

Abstract in brief

• The study examines how body size evolution and ecological factors influenced brain size (encephalization) in cave bears compared to their modern relatives, revealing that cave bears had significantly lower brain-to-body size ratios.
• Brain size in cave bears increased over time, but body size increased even more rapidly, leading to a decrease in encephalization; in contrast, in some species like Ursus malayanus, brain size increased while body size decreased.
• The findings suggest that cave bears, being herbivores, may have evolved smaller relative brain sizes as a physiological adaptation to their environment, possibly due to tradeoffs involving diet and fat storage strategies.]