Why do humans give birth to babies that are bigger that other species?

Question

For Example:Gorilla usually gives birth to a 4 pound baby
And a gorilla is bigger than the average female.

Answer 1

I believe it has to do with how advanced the human brain is.

Basically, humans have such an advanced brain compared to other animals, that it needs the larger body to support such an advanced brain, yet we are born so under developed (compared to other animals) because our brain has to undergo much more developement than other animals.

So in the example if the gorilla, you're talking about an animal that is about our size but gives birth to a smaller baby because the gorilla brain is not as complex and developed as the human brain.

And when you compare relative body size, you can say the same for an elephant. A typical mother can weight about 150 pounds giving birth to a 7 pound baby, or a ratio of about 20:1. According to Wikapedia, the typical elephant weights around 14,000 pounds and gives birth to a 265 pound baby, or a ratio of 50:1.

Answer 2

yeah weird huh? gestation periods are about the same (give or take a week or so, 266 in human 257 in gorilla), but humans give birth to much larger kids.

humans though have a much higher brain-to-body-mass ratio (our brains take up much more of our bodies). primate babies are born with a higher percentage of their brain size than humans. (humans are born with 23% while rhesus monkeys are born with 65% and chimpanzees 40.5%).

if you think about it in terms of brain size as opposed to overall weight, since primates have smaller brains in relation to their bodies, they can be born smaller and still have a relatively well developed brain.

the relatively large average size of a human baby is a balance between brain-to-body-mass ratio and the practicalities of natural childbirth (i.e. you don't want to make too hard on Mom). even though we only start out with 23% of our final brain size, the brain to body weight ratio is so that our babies end up bigger.

now i'm sure there's a lot more math involved in there somewhere involving logarithms and fancy math i never learned, so i guess that's the best i can come up with.

Answer 3

Studies have proven that human females actually give birth to an under developed offspring. Yes most mammals give birth to offspring that are dependant on them, but they are able to communicate and are mobile on their own terms.

That being said, there are several species that give birth to huge babies. Elephants give birth to damn near 500lb babies, whales same story.

This one will throw you for a loop. A panda will give birth to a baby no bigger than the palm of your hand....

Its just in our nature to give birth to larger offspring.

Answer 4

the first answer was correct. We give birth based on what we can handle naturally. Nature is a strange thing. Our babies are actually born before their time. If you look at animals their babies can walk eat, on their own, ours take several months to be able to do so.

Answer 5

You are comparing apples to oranges... Lets put it in perspective. The reason babies are born at the sizes they are born ...is to ensure survival. Smaller babies tend to have more problems (ie preterm babies). Baby gorilla's are prob born small so their mother can handle them easier. Look at horse's and cows.. Those things are HUGE when they are born! And elephants..whew..put us to shame. It's all about survival.

Answer 6

I think it is beacause it would be easier for gorillas handle the newborn if they are small

Answer 7

wow thats an interstin question!

hmm...maybe its because humans are more advanced than other species..dunno

good luck in findin an answer tho!!

Answer 8

so you could ask stupid questions