That stems in part from the presence in our brains of a well - developed frontal lobe, an evolutionary advantage we hold over the rest of the animal kingdom. (canadianbusiness.com)
The rest of the animal kingdom consists of «polyphasic» sleepers; they alternate sleep and wake cycles throughout a 24 - hour period. (inc.com)
And would be completely different then the rest of the animal kingdom. (religion.blogs.cnn.com)