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I don't have the evidence at hand but I am very sure from previous reading that our gait is still more energy efficient than other birds/animals. It is not abo

I don't have the evidence at hand but I am very sure from previous reading that our gait is still more energy efficient than other birds/animals. It is not about years of evolution it is about purpose. The downside is that our gait is basically a process of controlled falling, this need a really complex proprioceptive and neural control. The advantage is that we can travel _extremely_ long distances with minimal caloric intake when compared with other animals. So the claim from these researchers is that this system is efficient without the need for complex control systems (like in a human model). In practice a bird locomotor system is easier to control than a human one, it does not make the bird system more efficient because birds have been on earth longer.

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kayodelycaon 4y ago
Our gait isn't the reason humans can travel long-distance. It's that humans have more effective cooling and don't overheat in high temperatures. In cold climates, gray wolves have advantage in ultramarathon distances, provided they don't overheat. They can maintain 5~6mph on rough surfaces. Humans maintain 4~5 mph on prepared surfaces. (Wolves are lighter and their four clawed feet have significantly better traction than our two feet.) Any surprise we domesticated dogs? They can keep up with us. :)
- DoingIsLearning 4y ago
  Speed/traction have little to do with energy efficiency. The cooling adaptions we have allows to outperform most animals in long distance _running_ which is how the whole concept of 'persistence hunting' is based on. What I was pointing to is energy-efficiency in _walking_ long distances (we migrated long distances by walking not running). The bi-pedal flat foot heel-strike and roll gait that we have is the most energy efficient gait, the dogs in your example can keep up with us but still spend more energy per mile per kilo walking on four legs. The downside is that it is actually pretty hard to keep your center of mass on top of such a small Base of Support between your feet.
- sandworm101 4y ago
  Dogs have more than four feet. For purposes of traction, they have at least twenty. Each paw has five pads that contact the ground independent of one another. Add in their nails, and they have 36 articulated points of contact. Our toes are no longer load-bearing. Whereas we walk with the bulk of our weight on maybe four pads (heel+ball on each foot) dogs walk on an octopus-like network of structures. They will always have better traction.
adrian_b 4y ago
This fact about the energy efficiency of human locomotion is frequently mentioned. However, what is not mentioned is that this high efficiency is attained only when humans walk or when they run slowly, much more slowly than almost any other animal of a similar size. This ability would not have been of any use, had it not developed simultaneously with the ability of throwing sticks and stones much faster than any prey animal could accelerate. High endurance, even at slow speeds, was perfect for following the track of an animal wounded by a throwing weapon, until it became exhausted and it could be caught easily. Otherwise, walking randomly across the plains, with the hope of encountering by chance an animal which was exhausted enough to not be able to escape from your very slow, but efficient, running, would have been a losing strategy.
- DoingIsLearning 4y ago
  Wholly agree, which is why evolution wise we 'waste' a lot of resources on a big brain that is a huge energy sink. However my point was about GP's claim that birds gait was more efficient because they have been around for longer, which I disagree with.
- sandworm101 4y ago
  Humans also had one advantage: sweating. We are almost the only animal that can perspire across the bulk of our skin. So we can keep walking/running in the heat of the day when our prey and our predators cannot. Given enough time, in hot weather, humans can harass and run down uninjured deer and even horses. Our method of walking may not be efficient, but our ability to handle heat means we can keep moving long after everyone else has to hide in the shade. Just look at anyone walking a dog on a summer day. The dog is probably panting. The human is not. In a distance race, the human could easily outrun the dog.
  - adrian_b 4y ago
    I agree with this. There was not a single new ability which ensured that humans became the most dangerous hunting animals, but an ensemble of correlated abilities, and improved sweating was certainly one of them. Regarding the dogs, that is why their relatives are seldom important predators in warm climates. Even the best adapted to warmth among canids, like the African hunting dogs, have to remain much smaller than the large wolves of cold climates, for adequate cooling. When you compare humans with African predators, humans still have better cooling, but the difference is not so large as when you compare them with domesticated wolves, a.k.a. dogs.

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kayodelycaon 4y ago

Our gait isn't the reason humans can travel long-distance. It's that humans have more effective cooling and don't overheat in high temperatures. In cold climates, gray wolves have advantage in ultramarathon distances, provided they don't overheat. They can maintain 5~6mph on rough surfaces. Humans maintain 4~5 mph on prepared surfaces. (Wolves are lighter and their four clawed feet have significantly better traction than our two feet.) Any surprise we domesticated dogs? They can keep up with us. :)

DoingIsLearning 4y ago
Speed/traction have little to do with energy efficiency. The cooling adaptions we have allows to outperform most animals in long distance _running_ which is how the whole concept of 'persistence hunting' is based on. What I was pointing to is energy-efficiency in _walking_ long distances (we migrated long distances by walking not running). The bi-pedal flat foot heel-strike and roll gait that we have is the most energy efficient gait, the dogs in your example can keep up with us but still spend more energy per mile per kilo walking on four legs. The downside is that it is actually pretty hard to keep your center of mass on top of such a small Base of Support between your feet.
sandworm101 4y ago
Dogs have more than four feet. For purposes of traction, they have at least twenty. Each paw has five pads that contact the ground independent of one another. Add in their nails, and they have 36 articulated points of contact. Our toes are no longer load-bearing. Whereas we walk with the bulk of our weight on maybe four pads (heel+ball on each foot) dogs walk on an octopus-like network of structures. They will always have better traction.

adrian_b 4y ago

This fact about the energy efficiency of human locomotion is frequently mentioned. However, what is not mentioned is that this high efficiency is attained only when humans walk or when they run slowly, much more slowly than almost any other animal of a similar size. This ability would not have been of any use, had it not developed simultaneously with the ability of throwing sticks and stones much faster than any prey animal could accelerate. High endurance, even at slow speeds, was perfect for following the track of an animal wounded by a throwing weapon, until it became exhausted and it could be caught easily. Otherwise, walking randomly across the plains, with the hope of encountering by chance an animal which was exhausted enough to not be able to escape from your very slow, but efficient, running, would have been a losing strategy.

DoingIsLearning 4y ago
Wholly agree, which is why evolution wise we 'waste' a lot of resources on a big brain that is a huge energy sink. However my point was about GP's claim that birds gait was more efficient because they have been around for longer, which I disagree with.
sandworm101 4y ago
Humans also had one advantage: sweating. We are almost the only animal that can perspire across the bulk of our skin. So we can keep walking/running in the heat of the day when our prey and our predators cannot. Given enough time, in hot weather, humans can harass and run down uninjured deer and even horses. Our method of walking may not be efficient, but our ability to handle heat means we can keep moving long after everyone else has to hide in the shade. Just look at anyone walking a dog on a summer day. The dog is probably panting. The human is not. In a distance race, the human could easily outrun the dog.
- adrian_b 4y ago
  I agree with this. There was not a single new ability which ensured that humans became the most dangerous hunting animals, but an ensemble of correlated abilities, and improved sweating was certainly one of them. Regarding the dogs, that is why their relatives are seldom important predators in warm climates. Even the best adapted to warmth among canids, like the African hunting dogs, have to remain much smaller than the large wolves of cold climates, for adequate cooling. When you compare humans with African predators, humans still have better cooling, but the difference is not so large as when you compare them with domesticated wolves, a.k.a. dogs.