In mammals,the litter size is approximately half the number of mammae,known as the‘one-half rule’,which has been recognized since the time of Aristotle in ancient Greece(Aristotle,1937)and applies to many species(Gi...In mammals,the litter size is approximately half the number of mammae,known as the‘one-half rule’,which has been recognized since the time of Aristotle in ancient Greece(Aristotle,1937)and applies to many species(Gilbert,1986;Diamond,1987).In contrast,arboreal squirrels,including flying squirrels,notably diverge from this norm by producing fewer offspring(Gilbert,1986).However,the reasons underlying this smaller litter size in arboreal squirrels have long remained elusive.展开更多
文摘In mammals,the litter size is approximately half the number of mammae,known as the‘one-half rule’,which has been recognized since the time of Aristotle in ancient Greece(Aristotle,1937)and applies to many species(Gilbert,1986;Diamond,1987).In contrast,arboreal squirrels,including flying squirrels,notably diverge from this norm by producing fewer offspring(Gilbert,1986).However,the reasons underlying this smaller litter size in arboreal squirrels have long remained elusive.
