At this point in our evolutionary progress, the expected human gestation period is (roughly) nine months long. My question is, has this duration of time always been the same for homo sapiens? Or, are pregnancies getting longer/shorter?

My attempts so far: upon searching online, I was only able to find a single reddit thread, of which didn't provide much of anything. And then, on Wiki's page for gestation it provides a link that should contain content on the "evolution of gestation related features for mammals", however, the link revealed itself to just be a page that outlines all mammalian evolutionary developments, and I'm not able to find the forementioned gestation specific information within it.

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    $\begingroup$ First off, I am not one of the close voters. 1 vote is because pob (the answer to your question is probably unknown, but that's not really a good reason to vote to close I guess), the other because of homework (it indeed shows no prior research effort - you could do a Google search first, show your findings here and then decide to still ask the question yes or no). $\endgroup$
    – AliceD
    Aug 22, 2017 at 14:46
  • $\begingroup$ Yes, I think evolution didn't have much effect on the gestation period. $\endgroup$
    – ABcDexter
    Aug 22, 2017 at 14:48
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    $\begingroup$ @Charles Unfortunately, "homework" here is defined as doing background work on your own to try and answer the question. Even if you can't, to be able to say "this is what I have found and where I found it" is important to know the scope of possible answers. See meta for much discussion of the longstanding problem with the "homework" close. $\endgroup$
    – kmm
    Aug 22, 2017 at 14:58
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    $\begingroup$ @kmm I've updated my post to address this concern. Thanks :) $\endgroup$
    – user22020
    Aug 22, 2017 at 14:59
  • $\begingroup$ If pregnancy durations are different from the recent past, it wouldn't be at all clear whether this was due to evolution or other factors. There is also so much variation in what a "normal" pregnancy duration is in modern humans that this question couldn't be answered. The references to developing "more complex bodies with time" and efficiency at offspring development suggest this question is going way beyond the scope that it initially intended to. $\endgroup$
    – Bryan Krause
    Aug 22, 2017 at 17:22

1 Answer 1


human gestation period

According to the link gestation period doesn't vary much between great apes.

I don't see any signs that human are becoming "more complex". In fact human babies are uniquely underdeveloped compared with other mammals (large brain size, upright posture)

  • $\begingroup$ The article you link to seems to suggest that the gestation period is mostly dependent upon the size of the creature. So, if humans were to drastically increase/decrease in size, then perhaps gestation periods would also change? $\endgroup$
    – user22020
    Aug 31, 2017 at 14:29
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    $\begingroup$ But for the blue whale it is only 11 months. $\endgroup$
    – Alan Boyd
    Aug 31, 2017 at 14:40

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