How come certain animals (horses, moose, cows) can walk as soon as they’re born and humans can’t?


How come certain animals (horses, moose, cows) can walk as soon as they’re born and humans can’t?

In: Biology

Humans are actually born fairly under-developed compared to many animals.

The reason for this has something to do with the way we walk: “developed” requires a larger head, but a larger head requires a larger pelvis to fit through during birth. At the same time, pregnant women have enough trouble getting around with a normal-sized baby; while animals that walk on four feet don’t have so much of an issue, it would be difficult for pregnant women to carry much larger babies.

So it’s a trade-off: we finish our development outside the womb, after birth, and our mothers have to take close care of us–in exchange for them being able to walk upright and not have a birth with a risk of killing the child or breaking the mother’s pelvis.

Because humans aren’t as developed when we’re born, or our silly giant skulls would get stuck. That means, essentially, that the wiring to work out walking hasn’t quite been hooked up yet.

We’re born not fully developed.
Many other animals are similarly helpless when born, but they’re usually born sharing the womb with many other siblings.
Humans have to be born underdeveloped, despite usually being only born one at a time, because of the human skeleton’s adaptation to walking on two legs.
The human hip bones wouldn’t allow it to walk easily on two legs if it was wide enough to give birth to something bigger, it’s already straining as is.
Also a pregnant mother would not be able to keep up with a nomadic tribe if she was carrying a much heavier load.

The walking part has to do with the brain development. Many animals can’t walk at birth, but yes humans take almost a year to do it. But our brains are at the same point of development as other mammals.

Why our brains aren’t as developed at birth is unclear, the old idea that hip width and infant head size is not holding up to scrutiny of science. A chimps brain size at birth is 40% of adult size and humans it is 30%, but if ours was 40% of adult size that’s only 1-2 cm bigger. That is within the range of women’s hip width today. Also, the idea that wider hip width impedes walking isn’t accurate. When running and walking on a treadmill there was no correlation between hip width and walking ability. So we already are wide enough for a baby with a larger skull and we could be wider without it affecting walking. So, there is probably a different reason, a few have been purposed, but we’ll see if they hold up. Also, did you know humans pregnancy is longer than chimps, gorillas or orangutans!