This might have evolved in order to throw rocks, which was apparently one of our most important hunting and defence adaptations about 2M years ago after we migrated out of the forests.
I'm confused by this question. What is the most charitable[1] answer that you can think of that fits the statement? What are plausible alternatives to Homo sapiens? Could homo sapiens be a reasonable answer to your question, evolutionary history notwithstanding?
All old world monkeys and apes have opposable thumbs. Some of them still live in trees. So, leaving the wood and hunting by throwing stones does not seem reasonable to me as a reason for thumbs. But maybe I did not understand what is meant by “we”, hence my question.
I think it was also a law of large numbers game. With teamwork we'd all be throwing rocks simultaneously at the same target. Also the practice component that the other poster mentioned
I think you are measuring yourself on the wrong scale. Sure you might be less precise than some other humans, but clearly you are way better than a horse, or a wolf or many other animal who might be basically incapable to throw things.
Well it's not like homo sapiens suddenly appeared out of thin air and started doing their thing. It's not unreasonable to think the original comment talks about whoever was our predecessor down the line before that.
You could see this in action during that "Cheetah follows hiker" story a few months back. Here's the video queued to the moment where he throws a rock at it:
This is actually a really enlightening example. Everyone thinks about throwing to kill, but what about throwing to not die? It's so novel when another animal has it happen to them; they wtf out of there. Could vastly increase our survival rate.
We used to fight as kids by throwing rocks at each other, granted, that was the last line of defense (so to speak) to which we resorted only when we were really mad at each other. Also, the Intifadas, which were really effective in the short term given the huge resource asymmetry.
You can see orangutans spear fishing. I'd be surprised if pre-humans weren't using spears. Rocks are better for driving animals than they are as a weapon.
Outside of some pretty narrow circumstances, hunting (presumably small game) by chucking stones seems like a very hard way to make a living. It's easier for me to imagine a club being or non throwing stick/spear being a game changer than rock throwing.
There are living traditions of so many kinds of human hunting methods. Rock throwing is not in the top 1000. OTOH, there are many hunting/fishing methods that require nothing but bare hands and knowhow. If throwing rocks is such a breakthrough, why does no one do it anymore? Meanwhile, the few hunting methods and/or tools that chimps use are represented in extant human hunting behaviour.
Also fighting. I've never seen involved in a paleohuman duel but if I had to, I think I'd choose the hitting stick over a rock. The david vs goliath approach doesn't leave much room for error... and David had a sling.
I mean, the technical parts details of this theory is interesting. Explosive movement abilities developing in the Erectus lineage. I just think the rock throwing seems off.
Taken by itself the evolution of the human thumb may not be convincing, but along with other evidence, such as the changes around the human shoulder joint at around the same time period provides strong evidence that the ability to throw was a major factor in human evolution:
Is this all really throwing specific? Don't punching, hammering or other biomechanic also benefit from this? I'm not arguing the anatomy, just the "rock throwing" part.
I mean, throwing a rock might come in handy from time to time.. but it seems insufficient to be a driving force.. to me. Spears maybe.. We even have evidence of neanderthal spear making... but that's 1.5m years later.
You can make a living with a spear. Feeding a family by hunting birds with rocks seems near impossible. Seems like much less of a game changer than clubs, spears, digging sticks, etc. I can imagine a population dependent enough on these to create evolutionary pressures.
This is not an educated opinion... just a layman's speculation.
Meanwhile, I also suspect that hunting plays a bigger role than currently fashionable. Chimps are basically bound to live where figs grow. They need a variety of fig trees, because different varieties fruit at different times. No figs, no chimps. Their diet defines their range.
Most modern foraging cultures rely heavily on food plants that require processing: cooking, soaking, pounding, grinding.... We're not very good at digesting plants. Even chimps aren't great at it.
Assuming earlier ancestors were chimp-like, I think they had to have widened their diets beyond fruit... That means either meat or harder to digest vegetables.
Paranthropus (a divergent family of human-like species) do seem adapted to a wider vegetable diet. Their skull was crested, like a gorilla, to facilitate gnawing on uncooked roots, leaves & such. Homo & Australopithecines don't have such features. It just doesn't seem as likely that we evolved the ability to eat a wider vegetable range than chimps, and then regressed to a narrower range again.
The invention of fire is often referred to as "an external digestive system." You don't really need this for meat. Fresh meat is digestible. Even chimps can eat fresh meat, and we're more carnivorous than chimps. I think cooking, and other processing methods reintroduced us to vegetarian diets.
It's actually really surprising that we don't know what these early species ate. For most animals, diet defines lifestyle. A species that hunts or scavenges for most of its diet is subject to totally different pressures than a fig eater.
Rock throwing is a traditional hunting technique used by Aboriginal Australians.
Think about the scale economies. You have a tribe of 10 individuals all throwing rocks at a single being without having to close distance and risk injury.
It also appears to me to be a simpler invention for evolution than club usage and therefore more likely as an intermediate step, requiring less cortex. Accuracy and dexterity are no so important, just bipedalism and law of large numbers - after N rocks are thrown all you need is one of two connections.
This is all rather speculative, though, and I'm mostly talking out of my arse :-)
I don't. I can't find it now, but long ago I came across a description of a British captain and his crew landed on an island, and was confronted with the natives. The natives on had rocks, which they threw at them. They had the usual muskets and swords.
He described the rocks as huge, accurately thrown, and a never ending deluge. While you were ducking one, another hit you from another direction. He reported they broke arms and skulls. Had he been able to put more distance between himself and the rock throwers, so a musket could reach but a rock couldn't the outcome might have been different I guess, but they had just landed on a beach.
Rocks were the first distance effect weapons. The answer to "why doesn't anybody do it any more" is simply we have even better distance effect weapons now. Apes throw sticks now (not as effective as rocks), then we move onto rocks, and then slingshots, spears, then bows and arrows, and on we go.
If you came from Australia, you would know of a Test cricket batsman (ie, one of the best at the game in the world in a world that has over a billion following it), who misjudged a cricket ball (made of leather and stuffing, not rock), bowled at him (ie hand thrown) that was bounced of the ground (direct throws aren't legal), it smashed through the best helmets we had to offer and killed him. https://www.bbc.com/sport/cricket/30219440 He never regained consciousness. It wasn't some unfortunate stroke caused by some undetected aneurysm. It tore open an artery in his neck.
Technology is rarely usurped entirely. I definitely agree that rock throwing in fights still exists, and people will do it when necessary. It's not, however, a primary method of warfare or 1-on-1 conflict... outside of specific circumstances like defending walls. Maybe a situation where one side has armour and swords and the other has numbers. Even then, long term, I'd wager on the the former.
Hunting methods tend to perpetuate. I'm not saying that no one ever hunts birds with rocks. I'm sure many people do. I'm equally sure that very few ever fill the pot this way.
For rock throwing to have shaped our arms from Habilis to Erectus,
A just want to say that I'm not arguing against any core parts of the theory. Hand/thumb articulation. Shoulder biomechanics. Explosive/elastic ability. There's plenty of evidence for that. There are also plenty of alternative ways to theorize how this was useful.
I think rock throwing is the popular explanation because it assumes the least behavioural complexity. It could have been more complex behaviour, like spear throwing. We only have evidence of stone tools because composition. But, I think it's safe to assume that this represents a very small part of the Erectus (even habilis) tool repertoire.
If I had to accept rock throwing, my theory would be "alpha scavenger" behaviour, like brown bears. Rock throwing is be pretty useful for chasing large predators off their kill. This is an extant "hunting" method, stealing from lions. Cultures that still do this (now for cultural, more than nutritional reasons) use nothing but bravery. They walk in, projecting confidence. Lions retreat, at least temporarily. The people cut off a haunch and walk away. A crude stone knife/axe (the one tool we know was widely used) is an essential tool for this. You need to butcher super fast, before the lions regroup and try to recover the kill.
That'd be an evolutionary advantage. Lions & bears do this, but it takes a lot of body mass. If a band of 50kg animals can chase off a pride of 150kg animals or a single 250kg animal... this is very efficient. Usually being alpha scavenger requires a tradeoff: large, calories consumptive body size in exchange for access to calories.
Hard way to make a living, but at least plausible.
I'f you've had a pet bird, you might notice many birds have TWO opposable thumbs (toes actually).
So they can not only manipulate things, they can also grasp things quite securely, and do things like walk up the side of vertical objects and hang upside down.
I'm uncertain if they can do things like turn a screwdriver, which seems to come from the wrists more than anything.
and then there's the whole flying thing, which has kept them out of reach of most predators since the dawn of time.
I remember watching a large horse in a paddock, thinking how being 5% smarter wouldn’t help it much. Having thumbs struck me as being an excellent facilitator for realising benefits of increasing intelligence. Obviously it’s just one of many, as demonstrated by dolphins and birds.
TL;DR: opposable thumbs are characteristic of Homo species and not found in Australopithecus
The paper (pdf) Biomechanics of the human thumb and the evolution of dexterity [1]:
> Here, we develop a new approach to investigate the efficiency of thumb opposition, a fundamental component of manual dexterity, in several species of fossil hominins. Our work for the first time takes into account soft tissue as well as bone anatomy, integrating virtual modeling of musculus opponens pollicis and its interaction with three-dimensional bone shape form. Results indicate that a fundamental aspect of efficient thumb opposition appeared approximately 2 million years ago, possibly associated with our own genus Homo, and did not characterize Australopithecus, the earliest proposed stone tool maker. This was true also of the late Australopithecus species, Australopithecus sediba, previously found to exhibit human-like thumb proportions. In contrast, later Homo species, including the small-brained Homo naledi, show high levels of thumb opposition dexterity, highlighting the increasing importance of cultural processes and manual dexterity in later human evolution.
35 comments
[ 2.8 ms ] story [ 83.1 ms ] threadFrom a cell's point of view, there are no ancestors.
Otherwise, saying you are your father and mother would be consistent with what you initially said...
[1] https://en.m.wikipedia.org/wiki/Principle_of_charity
But I am glad that someone in my tribe can.
If you spend half an hour straight on throwing practice, you'll get quite good at it.
https://youtu.be/p25MgRZ9rJc?t=333
Outside of some pretty narrow circumstances, hunting (presumably small game) by chucking stones seems like a very hard way to make a living. It's easier for me to imagine a club being or non throwing stick/spear being a game changer than rock throwing.
There are living traditions of so many kinds of human hunting methods. Rock throwing is not in the top 1000. OTOH, there are many hunting/fishing methods that require nothing but bare hands and knowhow. If throwing rocks is such a breakthrough, why does no one do it anymore? Meanwhile, the few hunting methods and/or tools that chimps use are represented in extant human hunting behaviour.
Also fighting. I've never seen involved in a paleohuman duel but if I had to, I think I'd choose the hitting stick over a rock. The david vs goliath approach doesn't leave much room for error... and David had a sling.
I mean, the technical parts details of this theory is interesting. Explosive movement abilities developing in the Erectus lineage. I just think the rock throwing seems off.
https://www.bbc.com/news/science-environment-23061016#:~:tex....
I mean, throwing a rock might come in handy from time to time.. but it seems insufficient to be a driving force.. to me. Spears maybe.. We even have evidence of neanderthal spear making... but that's 1.5m years later.
You can make a living with a spear. Feeding a family by hunting birds with rocks seems near impossible. Seems like much less of a game changer than clubs, spears, digging sticks, etc. I can imagine a population dependent enough on these to create evolutionary pressures.
This is not an educated opinion... just a layman's speculation.
Meanwhile, I also suspect that hunting plays a bigger role than currently fashionable. Chimps are basically bound to live where figs grow. They need a variety of fig trees, because different varieties fruit at different times. No figs, no chimps. Their diet defines their range.
Most modern foraging cultures rely heavily on food plants that require processing: cooking, soaking, pounding, grinding.... We're not very good at digesting plants. Even chimps aren't great at it.
Assuming earlier ancestors were chimp-like, I think they had to have widened their diets beyond fruit... That means either meat or harder to digest vegetables.
Paranthropus (a divergent family of human-like species) do seem adapted to a wider vegetable diet. Their skull was crested, like a gorilla, to facilitate gnawing on uncooked roots, leaves & such. Homo & Australopithecines don't have such features. It just doesn't seem as likely that we evolved the ability to eat a wider vegetable range than chimps, and then regressed to a narrower range again.
The invention of fire is often referred to as "an external digestive system." You don't really need this for meat. Fresh meat is digestible. Even chimps can eat fresh meat, and we're more carnivorous than chimps. I think cooking, and other processing methods reintroduced us to vegetarian diets.
It's actually really surprising that we don't know what these early species ate. For most animals, diet defines lifestyle. A species that hunts or scavenges for most of its diet is subject to totally different pressures than a fig eater.
Think about the scale economies. You have a tribe of 10 individuals all throwing rocks at a single being without having to close distance and risk injury.
It also appears to me to be a simpler invention for evolution than club usage and therefore more likely as an intermediate step, requiring less cortex. Accuracy and dexterity are no so important, just bipedalism and law of large numbers - after N rocks are thrown all you need is one of two connections.
This is all rather speculative, though, and I'm mostly talking out of my arse :-)
He described the rocks as huge, accurately thrown, and a never ending deluge. While you were ducking one, another hit you from another direction. He reported they broke arms and skulls. Had he been able to put more distance between himself and the rock throwers, so a musket could reach but a rock couldn't the outcome might have been different I guess, but they had just landed on a beach.
Rocks were the first distance effect weapons. The answer to "why doesn't anybody do it any more" is simply we have even better distance effect weapons now. Apes throw sticks now (not as effective as rocks), then we move onto rocks, and then slingshots, spears, then bows and arrows, and on we go.
If you came from Australia, you would know of a Test cricket batsman (ie, one of the best at the game in the world in a world that has over a billion following it), who misjudged a cricket ball (made of leather and stuffing, not rock), bowled at him (ie hand thrown) that was bounced of the ground (direct throws aren't legal), it smashed through the best helmets we had to offer and killed him. https://www.bbc.com/sport/cricket/30219440 He never regained consciousness. It wasn't some unfortunate stroke caused by some undetected aneurysm. It tore open an artery in his neck.
Hunting methods tend to perpetuate. I'm not saying that no one ever hunts birds with rocks. I'm sure many people do. I'm equally sure that very few ever fill the pot this way.
For rock throwing to have shaped our arms from Habilis to Erectus,
A just want to say that I'm not arguing against any core parts of the theory. Hand/thumb articulation. Shoulder biomechanics. Explosive/elastic ability. There's plenty of evidence for that. There are also plenty of alternative ways to theorize how this was useful.
I think rock throwing is the popular explanation because it assumes the least behavioural complexity. It could have been more complex behaviour, like spear throwing. We only have evidence of stone tools because composition. But, I think it's safe to assume that this represents a very small part of the Erectus (even habilis) tool repertoire.
If I had to accept rock throwing, my theory would be "alpha scavenger" behaviour, like brown bears. Rock throwing is be pretty useful for chasing large predators off their kill. This is an extant "hunting" method, stealing from lions. Cultures that still do this (now for cultural, more than nutritional reasons) use nothing but bravery. They walk in, projecting confidence. Lions retreat, at least temporarily. The people cut off a haunch and walk away. A crude stone knife/axe (the one tool we know was widely used) is an essential tool for this. You need to butcher super fast, before the lions regroup and try to recover the kill.
That'd be an evolutionary advantage. Lions & bears do this, but it takes a lot of body mass. If a band of 50kg animals can chase off a pride of 150kg animals or a single 250kg animal... this is very efficient. Usually being alpha scavenger requires a tradeoff: large, calories consumptive body size in exchange for access to calories.
Hard way to make a living, but at least plausible.
Possibly spear fishing if aquatic upright ape theory has any merit
So they can not only manipulate things, they can also grasp things quite securely, and do things like walk up the side of vertical objects and hang upside down.
I'm uncertain if they can do things like turn a screwdriver, which seems to come from the wrists more than anything.
and then there's the whole flying thing, which has kept them out of reach of most predators since the dawn of time.
The paper (pdf) Biomechanics of the human thumb and the evolution of dexterity [1]:
> Here, we develop a new approach to investigate the efficiency of thumb opposition, a fundamental component of manual dexterity, in several species of fossil hominins. Our work for the first time takes into account soft tissue as well as bone anatomy, integrating virtual modeling of musculus opponens pollicis and its interaction with three-dimensional bone shape form. Results indicate that a fundamental aspect of efficient thumb opposition appeared approximately 2 million years ago, possibly associated with our own genus Homo, and did not characterize Australopithecus, the earliest proposed stone tool maker. This was true also of the late Australopithecus species, Australopithecus sediba, previously found to exhibit human-like thumb proportions. In contrast, later Homo species, including the small-brained Homo naledi, show high levels of thumb opposition dexterity, highlighting the increasing importance of cultural processes and manual dexterity in later human evolution.
[1] https://www.cell.com/current-biology/pdf/S0960-9822(20)31893...