Humans are effectively marsupials, we just don't have a pouch.

I remember, back in the heydey of the Discovery channel having real science programming, a Wild Discovery[1] about guanacos in the Andes. Within an hour, the baby guanaco was birthed, licked clean of placenta, and on it's feet scrambling unsteadily up 14k foot mountains after it's mother.

[1] I miss this show, and that era of basic cable documentary television so much...

I mean, we're similar in that regard, but were more closely related to literally all placental mammals than marsupials.

Its hard to imagine that our large brain came first and the birth canal was an afterthought :))

As the case with dolphins, humans rely on social interactions to survive. The more an animal relies on their caregiver, the more it relies on learning and the less it relies on instincts to survive.

The point is that the pelvis (and birth canal) size couldn't keep up with the increase in cranium size, possibly due to other selection pressures like the requirements of bipedal gait. Human females would need ludicrous hips if we were born more developed.

On the other hand skills like object permanence require the development outside the womb. I am sure nature would have found a way if it would be possible otherwise.

I seem to recall reading that this is due to a compromise between infant head size and womens' ability to walk efficiently.

It's quite remarkable the sacrifices that were made for the sake of increasing cranium size. Childbirth became a coin-flip for whether the child and mother even survive the ordeal, infants are born completely helpless for the first few months of life. It goes to show just how critical intelligence was for the survival of our species.

Dominant traits is not always about survival... Could be a sexual preference for intelligence. Nerds might have been cools a few 100 k years before we thought!

If you were smarter you could better tools, weapons and shelter... Or better ways to hunt and prepare food...

That would definitely help your family survive better.

Your parent makes the valid point that difficulty in producing such children does not necessarily demonstrate the value of this trait for survival. Peacock tail confers no survival merit except for sexual selection.

It very strongly demonstrates the value of the trait for gene survival, which is the important thing. The individual matters not.

> we're basically born at a stage of development that'd be considered a fetus for other animals in a lot of ways, and rely a lot more heavily on our parents as we continue our development.

And since parenting such an undeveloped creature requires high intelligence, we get more and more intelligent in a feedback loop [1].

[1] http://www.pnas.org/content/113/25/6874.abstract

The book ‘Sapiens’ by Yuval Harari talks exactly to this point. A really excellent read.

yep. many animals are born knowing how to walk and many other skills.

no shittin, a full sized human can't bear a full sized human. I think that's the same for all animals, though and doesn't explain the difference, unless you implied dolphins carry their unborn for way longer. which they don't. (I'll have to check)

Virtually every mammal (marsupials are, IIRC, the main exception) gives birth to young that are much more fully developed and physically capable than human newborns. Dolphins are definitely not exceptions here.

That they’d also be closer to same-species adults in cognitive function is not that surprising.

I wasn't so much disagreeing with the implied statement as I was criticizing your expression. You didn't add anything to the discussion I didn't read better in other comments. Point in case the focus is on the ratio of brainsize at birth and later, in relation to body size I might add.

> I wasn't so much disagreeing with the implied statement as I was criticizing your expression.

Your upthread comment wasn't a response to any expression of mine.

> You didn't add anything to the discussion I didn't read better in other comments.

If you just don't think a comment adds anything, but have no real disagreement with it, that's a good reason to either not respond or downvote.

It's not a good reason to deliberately misinterpret it and respond to that strawman sonthst you have an artificial disagreement.