So, in this sci-fi scenario, humans create uplifts or “algernons”; sapient animals created through genetic engineering. Torn between making these animals identical to their counterparts or being more or less humanoid, I am trying to design a form which can alternate between both; in other words, a form which can alternate between a near-erect, bipedal stance and a more normal, quadrupedal stance.

I am starting with dogs, (these being deemed the ideal candidates due to their social nature and friendliness to humans) but am having difficulty. The more I adjust their structure for bipedalism, the less canine they look, and vice versa. How can I design a “dog” that looks near-identical to a normal dog when on all fours, but can stand and walk comfortably upright?

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    $\begingroup$ Curious why they wouldn't start with apes (already nearly a human body plan) or dolphins (big brains already, just need some tech assistance to have manipulators). $\endgroup$
    – Zeiss Ikon
    Jan 11 at 17:41
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    $\begingroup$ @ZeissIkon the researchers are probably in the pocket of Big Furry. $\endgroup$ Jan 11 at 17:48
  • $\begingroup$ this would make a great Stealth-ops soldier. Also we've screwed up the genus Canis a whole lot already so why do we have to give them chronic back pain and the messed-up anatomy that comes with bipedalism? $\endgroup$ Jan 11 at 19:51
  • $\begingroup$ I hate to say it, but this is the reason why most SciFi stories and games present animal-based aliens with animal-looking heads (and maybe hands), but that's about it. If you think about it, the reason your bipedal dogs don't look like dogs anymore is because they're not. "Realistically," any animal that retained it's basic animal shape but became bipedal would have hips and legs (and, necessarily, shoulders and spine... need to balance all that mass) that look remarkably human.... Engineering is a harsh mistress. $\endgroup$
    – JBH
    Jan 11 at 23:46
  • $\begingroup$ After thinking about it a bit, some scifi/fantasy simply ignores how it happens and do it. Go watch the movie The Mummy Returns (here's a relevant clip), where the Anubis Warriors are bipedal dogs or consider how every werewolf story in history has been written and presented. Authors can dive too deep into the realism rabbit hole. $\endgroup$
    – JBH
    Jan 12 at 0:06

3 Answers 3


There's only one family of animals extant (at this time, anyway) that switch back and forth between bipedal and quadrupedal gaits with any level of comfort: the great apes (and their "quadrupedal" gait has a pretty strongly sloped spine due to short legs and long arms).

That said, the main keys will be hip joints and the neck/skull. A human can't walk like a dog, not only because our legs and arms are too different in length but because we can't readily tilt our heads back far enough to see forward comfortably with a horizontal spine. The opposite is true of dogs (and most quadrupeds): if they tip their heads forward enough to see ahead when upright, they'll give themselves serious neck problems.

My understanding is that the skull is the primary problem here -- the human (and great ape) skull joins to the spine at the bottom, while dogs (and cats, and bears, and cows and horses) more or less at the rear. To compensate this might require additional flexibility of the neck and strength in the neck muscles -- and with mammals generally limited to only seven cervical vertebrae, neck flexibility has its limits, too.

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    $\begingroup$ There are things like meerkats which probably have some or more of the required neck characteristics. $\endgroup$ Jan 11 at 17:52
  • $\begingroup$ @StarfishPrime House cats and domestic dogs can imitate the meerkat stand, but whether they can be comfortable in that posture for prolonged periods is the question. I've read that with dogs, being upright too long compresses their larynx or trachea. $\endgroup$
    – Zeiss Ikon
    Jan 11 at 18:25
  • $\begingroup$ @ZeissIkon Cats are easily able to recreate the "face-forward" human look, as are dogs. They're essentially doing it when they sit upright. $\endgroup$
    – stix
    Jan 11 at 20:04
  • $\begingroup$ When cats or dogs "sit" their spines are sloped at least as much as a gorilla's is when in quadruped ("knuckle walking") posture. As I noted above, dogs and cats can do this -- I can look forward when on my hands and knees, too, but if I do it for long I'll get a severe neck ache. $\endgroup$
    – Zeiss Ikon
    Jan 11 at 20:21
  • $\begingroup$ See this image: notice how much the trachea and esophagus would be compressed for the dog to stand fully upright and look forward: frontiersin.org/files/Articles/559055/fvets-07-559055-HTML/… $\endgroup$
    – Zeiss Ikon
    Jan 11 at 20:25

Answering this because I do have experience trying to create exactly this kind of creature.

To sum up my view of this sort of problem after researching this, as well as winged humanoids...

It's going to be a tradeoff between the two things you want your creature to be. The creature will, ideally, be more comfortable in one form than the other, otherwise it's going to do neither thing well. The more capacity you give the creature in one form, the more it's anatomy will inhibit it in the other. For instance, I settled for making my winged humanoids clumsy fliers with less arm strength than they would otherwise have. They also need to warm up their wings to extend the feathers, which is something that allows the feathers to retract a bit when not in use and lets them do normal things like sit in a chair... But they're hindered in that they can't take off quickly in an emergency.

Don't ever get discouraged by this. I was very discouraged at first when I realized how impractical some of my initial creature designs were. But sometimes that tradeoff can give you fun challenges, and especially in fiction, there's enough room to squeeze down or mitigate the drawbacks so that you can get something very close to what you wanted, but still be believable. Maybe even more so because the creature now has some well thought out weaknesses.

"Near-identical" might be a tall order, or it might be doable, depending on the extent of use you want them to make of each form. Bipedal digitigrades are a sliding scale. If your priority is on the "dog" form, you could have them look very doglike indeed with maybe some more developed muscles in the hind leg calf. They could stand for short periods, or squat comfortably with hands off the ground. That would enable conversation with humans and standing up for cool poses or to see further away.

Since this is sci Fi, perhaps they have some prosthetics or special shoes that assist them in standing without discomfort, but can be removed for more animalistic, four-legged tasks?

The more time you want them to be standing on two legs and walking, the more adaptation you are going to have to do. My own species has "thumb toes" on their feet which fold in for walking and fold out or grip to give better balance when standing still. The length of the "foot" should be decreased relative to the rest of the leg, bringing it closer to a human with elongated feet standing on tiptoes, if you want them to have a more stable biped stance. This makes walking on all fours less graceful, but has the advantage of making them very fast runners in biped form. Heavily biped digitigrades will need some alterations to their joints to accommodate the greater strain. Think thicker, sturdier legs that look like a hybrid between a human's and animal's. My species stands on a "heel" (actually the ball of the foot) thickly padded with cartilage.

Somebody else made an interesting point about the neck. You could take the opportunity to develop some physical adaptations regarding that, but again, if you're writing fiction you have a choice about how in depth you want to go.

Another thing you should consider is the arms/forelimbs. Dogs and cats have their elbows very close to their shoulders and a very long foreleg. This is the best arrangement for walking or running on all-fours. Humans have our elbows placed much further down, making the limb more flexible, but sacrificing it's ability to bear weight. Have you ever walked on all fours yourself? You'll notice that your legs are disproportionately long and that your elbows make it awkward to bear weight. But the "dog" elbows are useless for any kind of tool usage, and even kind of awkward for gesturing in conversation.

I don't know much about your world, either. Is there magic, or "sufficiently advanced technology" that would allow morphing or physical adjustments as they change stance? Biological nanobots? That could solve many problems, but I understand not everybody wants to go that route.

The role these animal people play in your world, society or any of the stories in it should influence which compromises you're willing to make, and which part of the sliding scale you want to put them on. Is it very important to you that they look like actual dogs? Then you may want to skew them towards being dogs that can stand up briefly for conversation but can't sustain that posture. For my species, the importance of making them human-like in tool making ability heavily influenced the outcome. I chose completely human elbow position and worked details into their culture to account for the fact that they aren't comfortable standing in one place for very long. They can't really run on four feet, but they can squat and crawl, and walk on four legs to get under a low spot easier than we can. It's always going to be a compromise. But again, think about the role you want them to play, and weigh the benefits of different degrees of adaptation.


Baboons are the answer Well, sort of. Baboons can both run with all 4 of their legs and use their front limbs as hands. If you want your canine to be able to change from bipedal to quadrupedal I think they would be the best and most efficient analogus you have. Yes, there is a trade of as your species will most probably be unable to run on their back limb only- look at humans we have our vertical pose which allows our arms to throw stings but we are the lames runners in the animal kingdom. With that in mind is safe to say that you sapient canines will also not have the same freedom of arm movement as we do for the reasons listed above.


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