Some animals are ready to go as soon as they are born. These are called precocial animals. They are born knowing how to walk.
It's interesting seeing what comes built-in. You can see this if you watch a horse being born. Within the first hour, the foal will stand, and despite long legs, this usually works the first time. Lying down, however, is not preprogrammed. I've watched a foal circle trying to figure out how to get down from standing, and finally collapsing to the ground in a heap. Standing up quickly is essential to survival, but smoothly lying down is not.
Within a day, a newborn foal can run with the herd.
Of the mammals, most of the equines and some of the rodents (beavers) are precocial.
Pigs are, monkeys are not. It's not closely tied to evolutionary ancestry.
It's interesting seeing what comes built-in. You can see this if you watch a horse being born. Within the first hour, the foal will stand, and despite long legs, this usually works the first time. Lying down, however, is not preprogrammed. I've watched a foal circle trying to figure out how to get down from standing, and finally collapsing to the ground in a heap. Standing up quickly is essential to survival, but smoothly lying down is not. Within a day, a newborn foal can run with the herd.
Of the mammals, most of the equines and some of the rodents (beavers) are precocial. Pigs are, monkeys are not. It's not closely tied to evolutionary ancestry.