Why can a newborn deer run but a newborn human cannot?
Asked on: Sep 15, 2023 04:34 PM
1
Excellent question! So, why can a newborn deer hit the ground running while a human baby can't even hold its head up? It all comes down to the difference between what we call "precocial" and "altricial" species. Deer are precocial, which means they're born relatively mature and mobile. They need to be able to run almost immediately to escape predators. On the other hand, humans are altricial, meaning we're born less developed and need more care.
Now, you might be thinking, "But Mr. Art, why don't humans just evolve to be born ready to run too?" Well, it's because of our big brains! Human infants are born with large heads because our brains are so big. If we stayed in the womb long enough to develop the ability to walk or run at birth like a deer does, our heads would simply be too big for a safe birth. So it's a trade-off - we get big brains but have to spend some time being helpless after birth.
And if you're wondering why human babies don't just grow faster after birth so they can start running around sooner - well, that's because of those big brains again! Our brains require so much energy that it slows down other aspects of our development. So while it might seem like a bummer that human babies can't do parkour straight out of the womb like Bambi can, remember that it's all part of the package deal that makes us humans!
References: Why Can't Newborn Humans Walk? Why Are Human Infants So Helpless?
