Why do humans walk upright?

[mistermack]

23 hours ago, swansont said:

Seeing predators more easily is an advantage the enhances survival probability. Efficient locomotion is an advantage the enhances survival probability.

This betrays a real lack of understanding of the evolutionary process. Evolution cannot foresee a future advantage. The advantage has to be there, in the present, at all stages. It's a process of tiny incremental changes. Our chimp-like ancestors were clumsy and inefficient on two feet. On four feet they were fast and nimble and more efficient. The more upright they became, the less efficient would have been their locomotion. They became upright in spite of a loss of efficiency.

 Have you ever seen a chimp walk upright? They tire of it very quickly, because they are simply not built for it. There is no chance whatsoever that efficiency of locomotion had anything to do with the onset of bipedalism. The necessary incremental advantage wasn't there, until millions of years later. 

Likewise, seeing predators is a silly idea. If you can see them, they can see you, and they are faster and more efficient movers than a little newly-bipedal human ancestor. Also, the idea stems from the savanna hypothesis, which is pretty much defunct, with the newest evidence indicating a change to bipedalism happening in much more heavily wooded environments, where distance vision doesn't count, and tree-climbing ability does. 

The real factors behind bipedalism are firstly that the history of Apes is generally of an increase in body size and a more upright build. So bipedalism wasn't a sudden event. The two are probably linked. Bigger animals can't run along branches as nimbly as small monkeys and squirrel types. It's probable that as apes got bigger, they would do better standing on one branch, and holding onto higher branches for safety and balance. So a more upright stance is one logical direction for bigger tree dwellers to follow. 

Another likely factor is the rise of monkeys, at the expense of apes, which is well documented in the fossil record. Monkeys are smaller, quicker and can handle less-ripe fruit than apes, so over millions of years, apes have been losing out to them, because they can beat the apes to the fruit. One way for apes to respond to this situation is to exploit food on the ground, and under it, by eating fungi, and digging out roots etc. So it's quite possible that we should be thanking monkeys for our modern bipedalism. 

[dimreepr]

19 minutes ago, mistermack said:

This betrays a real lack of understanding of the evolutionary process.

Indeed.

19 minutes ago, mistermack said:

The advantage has to be there, in the present, at all stages. It's a process of tiny incremental changes. Our chimp-like ancestors were clumsy and inefficient on two feet.

And then they weren't. 

Edited September 7, 2019 by dimreepr

[Mordred]

Here is a factor to consider. Humans need to carry their young. With chimps and apes they can cling to their mother thus freeing up the mothers hands for travel. Human babies don't have that kind of strength.

The ability to carry resources as well as infants is one advantage of bipeds. 

[howsois]

1 hour ago, Phi for All said:

There is evidence that early humans drove certain types of prey to the edges of cliffs so they'd fall to their deaths. No weapons needed. It's a pretty intelligent hunter that can get an animal to kill itself.

They can drive animals away. They don't use weapons. Why are these animals afraid of them?

[Mordred]

Humans today can drive herd animals without weapons. So why would this be surprising when those same animals run from a large number of humans back then.

[Phi for All]

11 minutes ago, howsois said:

They can drive animals away. They don't use weapons. Why are these animals afraid of them?

Intelligent human predators learned that herd animals can stampede when a bunch of hunters charge the herd on two feet, waving their arms, and making lots of noise. Must have been pretty scary looking to a quadruped, and is yet another example of the potential benefits of moving on just two of your four limbs. We can make ourselves look a LOT bigger.

[swansont]

1 hour ago, mistermack said:

This betrays a real lack of understanding of the evolutionary process. Evolution cannot foresee a future advantage. The advantage has to be there, in the present, at all stages. It's a process of tiny incremental changes.

I don’t see where I claimed a future advantage, or that the change was not incremental. 

Why is this not directed at the OP, who presented the scenario?

1 hour ago, mistermack said:

Our chimp-like ancestors were clumsy and inefficient on two feet. On four feet they were fast and nimble and more efficient. The more upright they became, the less efficient would have been their locomotion. They became upright in spite of a loss of efficiency.

This contradicted by the Nature paper I cited earlier. 

1 hour ago, mistermack said:

 Have you ever seen a chimp walk upright? They tire of it very quickly, because they are simply not built for it. There is no chance whatsoever that efficiency of locomotion had anything to do with the onset of bipedalism. The necessary incremental advantage wasn't there, until millions of years later. 

Likewise, seeing predators is a silly idea. If you can see them, they can see you, and they are faster and more efficient movers than a little newly-bipedal human ancestor. Also, the idea stems from the savanna hypothesis, which is pretty much defunct, with the newest evidence indicating a change to bipedalism happening in much more heavily wooded environments, where distance vision doesn't count, and tree-climbing ability does. 

And if you can’t see them, but they can still see you? That’s better, somehow?

 

[Mordred]

Definitely makes you look bigger than you really are. Good example why do bears stand upright when confronted 

11 minutes ago, Phi for All said:

Intelligent human predators learned that herd animals can stampede when a bunch of them charge the herd on two feet, waving their arms, and making lots of noise. Must have been pretty scary looking to a quadruped, and is yet another example of the potential benefits of moving on just two of your four limbs. 

 

[howsois]

17 minutes ago, Mordred said:

Humans today can drive herd animals without weapons. So why would this be surprising when those same animals run from a large number of humans back then.

Can wild animals be the same? Try driving bison without a weapon?

[Mordred]

I've done it with three dozen other people. I lived in an area that has very rare but ocassional bison. Back before I moved to a city. Little hint identify the Alpha male then drive him. Making lots of noise is a must but also waving objects tends to make you look bigger to animals with poor eyesight.

Edited September 7, 2019 by Mordred

[howsois]

13 minutes ago, Mordred said:

I've done it with three dozen other people. I lived in an area that has very rare but ocassional bison. Back before I moved to a city. Little hint identify the Alpha male then drive him. Making lots of noise is a must but also waving objects tends to make you look bigger to animals with poor eyesight.

The nature of animals is to try to avoid potential threats, especially those they have not seen. If they find a possible threat, they will choose to stay away, but it will not lead them to commit suicide. If there is no retreat, they will rush to you.

[Mordred]

Never corner a herd animal. You give them room to run and they will when provoked. They also have poor enough eyesight they won't see a cliff till it's too late. Animals would rather run than fight they don't take unnecessary risks 

Edited September 7, 2019 by Mordred

[howsois]

11 minutes ago, Mordred said:

Never corner a herd animal. You give them room to run and they will when provoked. They also have poor enough eyesight they won't see a cliff till it's too late. Animals would rather run than fight they don't take unnecessary risks 

You can get a sense of how fast buffalo can run, and how fast humans can run, even if we assume that the grasslands have a lot of cliffs.

[Mordred]

Man migrates to locations that provide terrain advantages ie near river banks

Edited September 7, 2019 by Mordred

[howsois]

5 minutes ago, Mordred said:

Man migrates to locations that provide terrain advantages ie near river banks

What can this explain?

[mistermack]

2 hours ago, swansont said:

This contradicted by the Nature paper I cited earlier. 

You are missing the fundamental point of the way evolution works, just as they did. 

Comparing modern humans to chimpanzees is totally irrelevant. Modern humans have had six million years of adapting to the upright stance. Evolution cannot foresee that situation, as I already explained to you. The only way that our four-footed ancestors would become more upright was if there was an evolutionary benefit at the time. 

Are you claiming that modern chimps could walk more efficiently, if they became a tiny bit more upright? It's a ludicrous suggestion. 

[zapatos]

27 minutes ago, mistermack said:

Are you claiming that modern chimps could walk more efficiently, if they became a tiny bit more upright? It's a ludicrous suggestion. 

Then don't make it. No one else did.

[swansont]

2 hours ago, mistermack said:

You are missing the fundamental point of the way evolution works, just as they did. 

Comparing modern humans to chimpanzees is totally irrelevant. Modern humans have had six million years of adapting to the upright stance. Evolution cannot foresee that situation, as I already explained to you. The only way that our four-footed ancestors would become more upright was if there was an evolutionary benefit at the time. 

Are you claiming that modern chimps could walk more efficiently, if they became a tiny bit more upright? It's a ludicrous suggestion. 

I am not the one presenting the scenario. I am rebutting the silly claim that the only advantage to walking upright is carrying a club.(and that walking is less efficient than continuing to stay on all fours)

Please read the thread

[Mordred]

3 hours ago, howsois said:

What can this explain?

What is needed to explain? You move to a location that offers a ready supply of food, that meets your hunting requirements. You find a source of water. Which rivers provide cut banks. You look for areas that provide the required stones for cutting flints and obsidian tools.

Just so happens many of those demands of immediate access also correspond to water supply. That in and of itself will bring game and vegetables to that region.

I fail to see why I would need to explain as as something as fundamental as moving to a location that maximizes your advantages due to that location.

A human looks small if on all four limbs, but stand him up and suddenly he appears larger. Add the ability to wave objects around with the only limit is strength and suddenly he appears far more threatening than on four legs.

Examine what the advantages are in bipedalism as opposed to being in four legs.

A) tool use

B) carry supplies

C) spot predators and game

D) it's actually more energy conservative (there are studies that show this)

E) you can reach better

F) you appear larger and more threatening

G) you have better endurance follows from D..

There is a huge range of advantages to walking on two limbs freeing those two limbs from  simply getting from point A to point B

Edited September 7, 2019 by Mordred

[howsois]

3 hours ago, Mordred said:

What is needed to explain? You move to a location that offers a ready supply of food, that meets your hunting requirements. You find a source of water. Which rivers provide cut banks. You look for areas that provide the required stones for cutting flints and obsidian tools.

Just so happens many of those demands of immediate access also correspond to water supply. That in and of itself will bring game and vegetables to that region.

I fail to see why I would need to explain as as something as fundamental as moving to a location that maximizes your advantages due to that location.

A human looks small if on all four limbs, but stand him up and suddenly he appears larger. Add the ability to wave objects around with the only limit is strength and suddenly he appears far more threatening than on four legs.

Examine what the advantages are in bipedalism as opposed to being in four legs.

A) tool use

B) carry supplies

C) spot predators and game

D) it's actually more energy conservative (there are studies that show this)

E) you can reach better

F) you appear larger and more threatening

G) you have better endurance follows from D..

There is a huge range of advantages to walking on two limbs freeing those two limbs from  simply getting from point A to point B

I understand what you mean. You think that bluffing is an effective way to survive. It is also a way to push prey into desperation. There are many animals that know how to bluff, such as chimpanzees, chickens, bulls, etc. Whether it is the same kind or different types, they understand better what is the real strength. Human beings do not rely on weapons, not tools, even the current high intelligence can not survive in the wild.

You try 10 people, no,20 people, to scare off a lion. No weapons.
You can call on some people to experiment. Don't use weapons to the nature reserve to experience the survival of intelligence. The administrators of the reserve will not let you in, because he is worried about your life, not wild animals.
One of the theories I have said:Food and safety are the two basic elements of animal survival. you can't guarantee these two points, you have no chance to survive.

Edited September 8, 2019 by howsois

[Mordred]

Regardless those are fundamental  aspects to success in the wild. They may not work all the time but that's part of the risk. Spears and arrows or even guns aren't always successful.

 You can come up with whatever scenario you want to every situation to counter the points we make. Doesn't change the details that a percentage of the time in the right circumstances you can have success.

Much like you think a bunch of humans can't cause a stampede of Bison when we can do so today.

The points raised by numerous members has validity and are possible aspects of why humans evolved to walking. You should seriously consider each one instead of coming up with circumstances that any smart human wouldn't try.

Good example is your lion scenario in the last post. There is a big difference between driving off a lion and driving herbivores. Yet villages in Africa have to deal with lions on a regular basis. They have their success rates. 

I grew up in Grizzley bear country, I lost count of how many bears I have run across alone in the woods without any weapon. They usually saunter off unless you threaten them or endanger their cubs.

Edited September 8, 2019 by Mordred

[howsois]

3 minutes ago, Mordred said:

Regardless those are fundamental  aspects to success in the wild. They may not work all the time but that's part of the risk. Spears and arrows or even guns aren't always successful.

 You can come up with whatever scenario you want to every situation to counter the points we make. Doesn't change the details that a percentage of the time in the right circumstances you can have success.

Much like you think a bunch of humans can't cause a stampede of Bison when we can do so today.

The ingenuity of human beings can only be reflected in the invention and use of tools. Without the tools, human beings cannot survive, even now.

[Mordred]

So you claim yet part of my survival training had me in the timberland for a month with nothing but a soap dish of food and two jerry cans of water. Though we did have a radio for emergencies.

Yet I survived just fine without any weapons. I didn't even bother making a spear. Their wasn't a single day I couldn't find something to eat. (Though 90 percent of the time it tasted qrouse)

Edited September 8, 2019 by Mordred

[howsois]

5 minutes ago, howsois said:

The ingenuity of human beings can only be reflected in the invention and use of tools. Without the tools, human beings cannot survive, even now.

 Human innovation leads to human evolution.Human beings do not have the innovation of modern agriculture. How many people can survive? Human beings have no agriculture, how many people can survive? How many people can survive without human tools?

9 minutes ago, Mordred said:

So you claim yet part of my survival training had me in the timberland for a month with nothing but a soap dish of food and two jerry cans of water. Though we did have a radio for emergencies.

Yet I survived just fine without any weapons. I didn't even bother making a spear. Their wasn't a single day I couldn't find something to eat. (Though 90 percent of the time it tasted qrouse)

How do you keep yourself safe?

[Mordred]

Don't judge ppl today to ppl that existed before all these inventions. You would be amazed how much food exists in every forest or even in grasslands.

 Desert and artic survival is tricky but possible. 

10 minutes ago, howsois said:

 

How do you keep yourself safe?

Being alert and sleeping in a safe area such as a tree. Grizzly bears can't climb trees and mountain lions are a rare occurrence.  The biggest danger is wolves. That was for timberland survival. Every area has its own challenges. 

Edited September 8, 2019 by Mordred