Seems to me that even with our advances we suffer from an excessive amount of complications for a natural act.
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Yes. Humans have evolved to do a lot of really cool things. But having an easy childbirth is not one of them. This is primarily for two reasons. The first reason is that we have big heads to house our big brains. The other reason is that we have relatively narrow hips. Bipedal movement requires narrower hips, so we can keep our feet underneath us. The net result is we have a big head that needs to fit through a small opening. We even evolved to give birth very early in the gestation process. If we give birth earlier the baby is smaller and less likely to kill the mother. This is one of the reasons human babies are so useless when born.
There are two factors at play.
One, humans have “unnaturally” large heads at birth, due to our large brains. At the same time our pelvises have a particularly narrow hole due to our adaptation to upright walking. Those do cause some issues.
Two is something that compounds one. Women are forced to give birth laying on their backs for the benefit of the doctor overseeing the birth, which is thoroughly unnatural. Traditionally birth was (and in many places still is) performed squatting (or perhaps sitting as well, I’m not entirely sure about that), which lets gravity aid with the birth, and puts less strain on the mother’s body.
There’s two reasons for this that occurred during our evolution. The first is brain size. We have larger brains which means a bigger head. Now this is partially made up for by having pieces of our skull unfused at birth. The second and probably more important reason is due to the pelvis evolving for upright walking. The pelvis is more narrow which leads to a smaller birth canal.
This question has been asked before so you might search to find more answers.
Short version – our big stupid brains versus our bipedal walking
Slightly longer version – So our big brains are the thing that makes us… well successful as a species. But those big brains come at a cost – they need to be formed early on. Now this might not be an issue except that we ALSO developed a bipedal approach to walking which is stellar for endurance running and survival but also narrows the hips and the birth canal. End result is that women are trying to push a thing (the human head) which has a minimum size requirement through an opening (the birth canal) which is only barely big enough to handle it.
While humans may have relatively bad childbirth experiences compared with many mammals, I don’t imagine it is the absolute worst of the whole animal kingdom. For example, there are some animals, such as the crab spider, whose reproductive cycles end in the offspring eating the mother.
To be fair, animals that have difficulty birthing tend to not live or produce viable offspring, which kinda cuts down on animals having historically difficult births.
Hi, vet tech here. Therianology and animal parturition is kinda my bag.
I’m not going to say animals do not experience difficulties in the birthing process. Far from it. “Dystocia,” or, difficulties that interfere with the birth process, are common to see in the veterinary field. In horses and cows it can be startlingly common to have a calf or foal get stuck, come out the wrong way, or half a dozen other things that can result in the death of the neonates and/or the dam. Sheep and goats, too. The term “water baby” is never good. But most of my expertise is with cats and dogs, so let me use them as more concrete examples.
Lots of folks here have pointed out how our giant heads make birthing difficult. I’m here to tell you, it makes it damn near *impossible* for some dog breeds. The English Bulldog, for example, is almost always delivered via c-section. The way we have bred these creatures has created a stupidly mismatched ratio of head to pelvis, and – leaving aside that their anatomy is so malformed that half the time they can’t even physically copulate – they honestly should not exist. Nature doesn’t really allow for things that inhibit reproduction. Being unable to pass a neonate through the birth canal is a big one.
Much of that is our fault. Like selectively breeding ourselves for smarter mates and bigger brains that make our heads rather uncooperative to the whole “birthing” thing, we have selectively bred dogs to a point where their bodies would not otherwise survive without intervention. (I could go on a rant here about brachycephalism, elongated soft pallettes, stenosis nares, and more… but that’s not the question you asked.) We have done this most extensively with dogs and some horse breeds, which is why we see it so frequently in them. You don’t see it nearly as often in, say, cats.
Rare is the cat who has dystocia. At least your run-of-the-mill, heaven-knows-what breed created from this gangled ratter in the barn. Cats haven’t been quite so particularly bred. Granted, we’ve still selectively bred cats in some breeds so’s to give them every last disadvantage we have to dogs (in the name of “cute”), like the Persian, but those are much fewer and further between than your common mackerel tabby from the dumpster. These cats come from a long line of “can you really consider this animal ‘domesticated'” stock that in two generations can go from lap cat to feral. You don’t survive in the wild to pass on your genes if you suck at producing offspring. Rare is the cat who has dystocia; rarer still is the Persian who can cut it as a feral.
Where am I going with all this? Well, you kinda answered your own question: humans do, in fact, tend to have more difficulty birthing than most animals… and that’s because a lot of our ancestors only survived the birthing process with medical intervention. Animals don’t generally get that luxury of midwifery, physican assistance, or post-partum medical attention like humans do. And, if the birth goes badly, they don’t usually get the chance to repeat that attempt. Nature is cruel, but she is also precise: only those who can survive reproduction get to keep doing it, and produce more of the same.
Humans just… well. We tend to give Nature the finger.
Not if you narrow it down to mammals, especially mammals that have few offspring. You exist to propagate your genes. You have to push the envelope, put yourself in harm’s way. You’ve got to leave everything on the field. If you don’t, your descendants will be outnumbered by the descendants of those who did.
So, there is the thing about humans and skulls and brains and pelvic structure, yes. But lots of other species push the envelope in other ways, not just brain pans, most notably in twins. We’re hardly the only mammal that typically has one offspring. Twins are hard for a human. They’re also hard on deer and whales, but they have twins. Whales, not as often. Deer, it’s more common than it is in humans. And it’s dangerous for them. If it weren’t, they’d have twins all the time. Which they don’t.
So, moose die while birthing twins. Not all the time, or they’d evolve to never have twins. They’re gambling that it’ll turn out okay, and that if it doesn’t, they had plenty of singleton moslings already to carry on the line.
Evolution is a numbers game. Playing it safe so you can live a long time after your last child is ready to reproduce isn’t a great strategy. That’s as true for mooses as it was for your great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-great-grandma.
We’re definitely up there, but the hyena has is pretty bad, too. The hyena gives birth through its clitoris and sometimes the baby gets stuck and suffocated. It’s mainly just a problem on the first child though since the first one tears the clitoris making future births easier.
Hyenas have it far worse. The females genitalia mimic the penis, and birth through it leads to tears (which can kill the mother) and a high percentage of deaths among the cubs. So painful, sometimes fatal to the mother, and often fatal to the offspring.
Cows can’t have a baby unless somebody is shoulders deep in there. Source: any tv show or movie with a ranch
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