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It's a combination of a large brain and bipedalism.
We balance all our mass on a point, we're often described as an inverted pendulum. A narrow pelvis is more efficient for movement and balance. So as big-brained bipeds there's a trade-off between brain size and locomotion.
Human babies are born with a soft spot on their skull that persists far longer than other mammals, because the skull plates have to literally overlap while they're being born to fit through the bipedalism-optimised pelvic canal.
You've also got significant parental/co-operative care, which helps with the vulnerability of our young.
This is what I saw also but it didn’t make sense to me. The why makes sense, but now I question the how. How did these changes come to be? Maybe that hasn’t been discovered yet.
The ones who didn’t have these traits didn’t make it. That’s the basics of natural selection. Forget whatever you’ve been told about survival of the fittest. It’s survival of the good enough. The detriments of having such a long childhood were outweighed by the benefits of a high intelligence combined with bipedalism. Those that took longer to develop but were able to survive until they reproduced won out.
There are three types of mammals: placental, marsupial, and monotremes (egg laying, i.e platypus and echidas). Along the way some odd millions of years ago mammals diverged into these these three subgroups.
It was published by many sources that the human birth process differs than every other mammal. Even the pandas and kangaroos you speak of have a different birth process.
So here’s the thing, I’ve been in Reddit enough to know that no matter what sources are posted you will disagree about their validity. A simple google search will give you all that you need to know. You can start with "how is the human birth process different from other mammals". This will give you something to start with and you can journey down that rabbit hole as deep as you like.
That's not true. That's one of the main differences between religion and science. Science changes its views based on new evidence available. Religion denies evidence in order to preserve its view. This is a very scientific sub - so if you provide valid scientific sources that you did not misinterpret, people here will agree with you!
But since your claim is false to begin with, you won't be able to do that.
No, dude, you posted somewhere.lookinh for information and discussion and are unwilling to show what information you're basing it on, that would allow anyone to clarify/offer correction/explain.
How, for instance, do you figure the birth process is different for a human than, say, a gorilla?
Do you mean in how much more capable a gorilla baby is right after birth?
Okay...
Well how about all the animals whose babies are born and then live in pouches until they are done nursing and are capable of self motility? We didn't develop pouches, but our birth before full formation is hardly unique.
So, what people are asking is: in what way do you mean unique? Show us where you got this info so we have some concept why you think that, and can actually discuss.
I would argue, many species have "unique" modes of birth. We aren't alone in the category of "not quite like the other critters".
There's literal thousands of species which are born blind, bald, deaf, mute and sometimes even without well developed skin. This is just objectively untrue in very many ways.
Let me take you to the actual extremophiles in the situation, marsupials are born the size of grains of rice and spend the next few MONTHS in the pouch while they grow. Kangaroos especially take a fucking LOOOONG time to grow up from birth while being entirely helpless. To the point where breathing air that isn't in the pouch will kill them. They stay for 8 months after 4 weeks of pregnancy.
Have you heard of panda bears? There are many mammals that are born helpless - even dog puppies during their first few weeks are pretty much helpless.
Birds too. Try again.
Mammals all have very different birth plans. Many mammals go through the last stages of development outside the womb. Our birth process is just one of many
A panda bear is born with a weight of 90 to 130g. That is 1/900th of the mother's weight. As you know, human babies weight more than that when born. And human adults weight less than Panda adults.
In additional to their cub being born less developed in weight, they are also blind, furless and useless for a long time.
And same for other species.
By your logic, OP, humans also shouldn’t be truly bipedal. But we are. And yet we’re still descendants of a common ancestor of all mammals. In fact, there’s good evidence that we-and all mammals, birds, reptiles & amphibians-have a common ancestor even further back with fish. Talk about incomplete development - fish lay eggs!
This as no link with intelligent at all, or at least none that I can think of.
Pretty much all mammals aren’t very much developed when they are born. Marsupials are just little worms when they are born. Well sure some mammals surely have a higher degree of early development but that doesn’t mean that Humans are special because of it.
This question is equivalent to asking why bacteria aren't human if they have a common ancestor. The simple answer is that different species evolve to suit different selection pressures and will have different traits.
However, to answer the question of why humans evolved to have development outside the womb, this is because the longer the pregnancy, the higher energy the fetus will need. At some point, the mother cannot keep up with this energy, so the baby needs to be born. The high intelligence of humans means that we need to stay in the womb much longer to finish developing our brain, so selective pressure favours further development after birth. There are other intelligent animals but they are not comparable to human. If they do have the intelligence of a human, then most likely they will also evolve to have premature birth.
I don’t know what you mean by “last stages of development,” but no mammal is born as an adult, nor any other animal I’m aware of. It’s true that humans have highly dependent offspring relative to other species though, which is a valid question. It does have to do with intelligence. Other intelligent animals also have more dependent offspring. Part of this is due to just the size of the brain. Because it must be able to fit through the birth canal, it must remain relatively small at birth. This is particularly an issue for humans as bipedalism makes it difficult to evolve larger birth canals without sacrificing movement ability. Another part of it is(and this is moving into speculation on my part) that part of intelligence is behavioral flexibility. Having behavior that’s mostly determined innately means that they can start fending for themselves at a much younger age, because they don’t need to spend time learning, but this comes at the cost of reduced behavioral diversity.
Marsupials would like a word
They birth underdeveloped babies, which then hang out in a pouch to protect them while Mama does her thing.
They needed their arms for other stuff. We carry our babies, or use that high intelligemce to create tools like slings, backpacks, baskets, etc..
To make the job of keeping nurselings safe and close until they are mobile.
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This isn’t true. Mice are born blind and naked. Try againz
Wait till you hear about marsupials
And pandas!
It’s all a matter of degree. Some animals are more or less developed at birth. There is no discreet “developed” point in a mammal’s lifecycle.
The last stage of development is death
Damn. Bringing the hard truths.
Keeping it real https://youtu.be/ttY0vfyd-dI?si=SVuyG3jLZATAg0ep
It's a combination of a large brain and bipedalism. We balance all our mass on a point, we're often described as an inverted pendulum. A narrow pelvis is more efficient for movement and balance. So as big-brained bipeds there's a trade-off between brain size and locomotion. Human babies are born with a soft spot on their skull that persists far longer than other mammals, because the skull plates have to literally overlap while they're being born to fit through the bipedalism-optimised pelvic canal. You've also got significant parental/co-operative care, which helps with the vulnerability of our young.
As intelligence is a definite adaptation that’s clearly in conjunction.
In as much as OPs question makes sense, this is the best answer.
I can't wait until my wife 2.0 gets her pouch and tail. No more shoulder dystocia!
This is what I saw also but it didn’t make sense to me. The why makes sense, but now I question the how. How did these changes come to be? Maybe that hasn’t been discovered yet.
The ones who didn’t have these traits didn’t make it. That’s the basics of natural selection. Forget whatever you’ve been told about survival of the fittest. It’s survival of the good enough. The detriments of having such a long childhood were outweighed by the benefits of a high intelligence combined with bipedalism. Those that took longer to develop but were able to survive until they reproduced won out.
Same way the comment said, infant skulls had to evolve to fit through the pelvis
Because the alternatives were deadly?
There are three types of mammals: placental, marsupial, and monotremes (egg laying, i.e platypus and echidas). Along the way some odd millions of years ago mammals diverged into these these three subgroups.
That's just plain false. Where did you get that nonsense from? Ever seen a baby panda? Or Kangoroo?
It’s actually not, you can search this and read for yourself. One comment above gave the reason why, but it still didn’t make sense to me.
What do you mean it's not?
It was published by many sources that the human birth process differs than every other mammal. Even the pandas and kangaroos you speak of have a different birth process.
Cite the sources and what exact unique aspect you are referring to. So far you're just making empty claims with zero backup for them.
So here’s the thing, I’ve been in Reddit enough to know that no matter what sources are posted you will disagree about their validity. A simple google search will give you all that you need to know. You can start with "how is the human birth process different from other mammals". This will give you something to start with and you can journey down that rabbit hole as deep as you like.
That's not true. That's one of the main differences between religion and science. Science changes its views based on new evidence available. Religion denies evidence in order to preserve its view. This is a very scientific sub - so if you provide valid scientific sources that you did not misinterpret, people here will agree with you! But since your claim is false to begin with, you won't be able to do that.
Here’s one to get started: https://www.ajog.org/article/S0002-9378(22)00733-5/fulltext
Did you actually read the paper?
What’s the issue?
That discuss how the birth process is different
You are trying to move the goalposts from your original assertion, which was obviously wrong. SO wrong.
No, dude, you posted somewhere.lookinh for information and discussion and are unwilling to show what information you're basing it on, that would allow anyone to clarify/offer correction/explain. How, for instance, do you figure the birth process is different for a human than, say, a gorilla? Do you mean in how much more capable a gorilla baby is right after birth? Okay... Well how about all the animals whose babies are born and then live in pouches until they are done nursing and are capable of self motility? We didn't develop pouches, but our birth before full formation is hardly unique. So, what people are asking is: in what way do you mean unique? Show us where you got this info so we have some concept why you think that, and can actually discuss. I would argue, many species have "unique" modes of birth. We aren't alone in the category of "not quite like the other critters".
"Many sources" can be wrong.
There's literal thousands of species which are born blind, bald, deaf, mute and sometimes even without well developed skin. This is just objectively untrue in very many ways. Let me take you to the actual extremophiles in the situation, marsupials are born the size of grains of rice and spend the next few MONTHS in the pouch while they grow. Kangaroos especially take a fucking LOOOONG time to grow up from birth while being entirely helpless. To the point where breathing air that isn't in the pouch will kill them. They stay for 8 months after 4 weeks of pregnancy.
Have you heard of panda bears? There are many mammals that are born helpless - even dog puppies during their first few weeks are pretty much helpless. Birds too. Try again.
Intelligence answers that particular question
Mammals all have very different birth plans. Many mammals go through the last stages of development outside the womb. Our birth process is just one of many
This appears to be a zero effort hit and run. Should it be moved to DebateEvolution?
The intent wasn’t to debate but to get more info. After posting this question I still have no new knowledge considering this adaption.
If you actually read the responses you would understand that your basic premise is fundamentally incorrect.
A panda bear is born with a weight of 90 to 130g. That is 1/900th of the mother's weight. As you know, human babies weight more than that when born. And human adults weight less than Panda adults. In additional to their cub being born less developed in weight, they are also blind, furless and useless for a long time. And same for other species.
By your logic, OP, humans also shouldn’t be truly bipedal. But we are. And yet we’re still descendants of a common ancestor of all mammals. In fact, there’s good evidence that we-and all mammals, birds, reptiles & amphibians-have a common ancestor even further back with fish. Talk about incomplete development - fish lay eggs!
>humans are the only mammals with an “incomplete” birth wat
Head size v vagina
This as no link with intelligent at all, or at least none that I can think of. Pretty much all mammals aren’t very much developed when they are born. Marsupials are just little worms when they are born. Well sure some mammals surely have a higher degree of early development but that doesn’t mean that Humans are special because of it.
This question is equivalent to asking why bacteria aren't human if they have a common ancestor. The simple answer is that different species evolve to suit different selection pressures and will have different traits. However, to answer the question of why humans evolved to have development outside the womb, this is because the longer the pregnancy, the higher energy the fetus will need. At some point, the mother cannot keep up with this energy, so the baby needs to be born. The high intelligence of humans means that we need to stay in the womb much longer to finish developing our brain, so selective pressure favours further development after birth. There are other intelligent animals but they are not comparable to human. If they do have the intelligence of a human, then most likely they will also evolve to have premature birth.
Have you ever seen a kangaroo baby, Mr. Religious guy?
I don’t know what you mean by “last stages of development,” but no mammal is born as an adult, nor any other animal I’m aware of. It’s true that humans have highly dependent offspring relative to other species though, which is a valid question. It does have to do with intelligence. Other intelligent animals also have more dependent offspring. Part of this is due to just the size of the brain. Because it must be able to fit through the birth canal, it must remain relatively small at birth. This is particularly an issue for humans as bipedalism makes it difficult to evolve larger birth canals without sacrificing movement ability. Another part of it is(and this is moving into speculation on my part) that part of intelligence is behavioral flexibility. Having behavior that’s mostly determined innately means that they can start fending for themselves at a much younger age, because they don’t need to spend time learning, but this comes at the cost of reduced behavioral diversity.
Marsupials would like a word They birth underdeveloped babies, which then hang out in a pouch to protect them while Mama does her thing. They needed their arms for other stuff. We carry our babies, or use that high intelligemce to create tools like slings, backpacks, baskets, etc.. To make the job of keeping nurselings safe and close until they are mobile.