Carnivores have experienced stronger natural selection than plant-eating animals, perhaps because of their limited diet.
Joo-Hong Yeo at the National Institute of Biological Resources in the Republic of Korea and his colleagues compared the genomes of 18 mammals, including carnivores such as leopards, omnivores such as humans, and herbivores such as giant pandas. They found that carnivore genomes have lost many genes for carbohydrate digestion, and share changes to genes involved in muscle strength and agility, making them good hunters. By contrast, omnivore and herbivore genomes shared fewer adaptations with others in their groups, suggesting that their diets have imposed weaker selection compared with that of carnivores.
Many big cats showed recent losses in genetic diversity, suggesting that population declines may be linked to their strict diet.