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Elastic energy storage in the shoulder: evolution of high-speed throwing in Homo (nature.com)
22 points by bookofjoe 26 days ago | hide | past | web | favorite | 13 comments

While throwing for hunting purposes would have been useful, throwing for defensive purposes likely would have been the initial impetus for throwing evolving to a fine art.

Imagine yourself alone on the plains of Africa and facing a lion or two. Your odds are not good. Even a group of people on the plains of Africa facing a few lions with no ability to throw stones looks like a losing proposition.

However a group of people in an outward facing circle facing lions and each with a pile of stones to throw with deadly accuracy, now this is something that even lions would think twice about.

The thing about defence is you don't have to move, the stones are prepared before hand. The predator has to come to you and is therefore easier to hit, preferably in the head. Sticks and stones will break their bones but names will never hurt them.

I agree with your point, but I would expand on it to say that defense could have even more important implications for scavenging than for surviving predation. Being able to scare predators off a kill [1] makes scavenging a lot easier. And then you can apply the same means to hunting, which is also more fruitful because you can hold your own kills.

You wouldn't even need to be strong enough for lions to start with; every step up the pecking order would be an advantage.

I don't envy paleontologists and archaeologists trying to make a case for "why" an adaptation emerged when it has so many plausible advantages, especially when cultural developments might have happened too fast or at too great a distance in the past for us to have an accurate idea of their timing.

[1] https://www.youtube.com/watch?v=TBpu4DAvwI8

Some very good points here :)

That is an interesting explanation, but felines usually hunt in the night and our low light vision wouldn't allow our ancestors to defend themselves in a way that relied so much in accuracy during the dark.

I used lions here just as an example. It could be hyenas or wild dogs and others.

And now I push a mouse around on a desk with this amazing arm.

Just don't reproduce, and you'll keep our evolutionary trajectory on track. In a few generations we'll be able to throw the CO2 so far it never bothers us again.

Interestingly enough, throwing is the human trait / behavior with the biggest known measured disparity between the genders on average (this includes physical, mental, and emotional abilities).

See Table 1 https://www.apa.org/pubs/journals/releases/amp-606581.pdf

The largest gender differences in Table 1 are in the domain of motor performance, particularly for measures such as throwing velocity (d = 2.18) and throwing distance (d = 1.98)

The Cohen's d value here is difference in means between two populations, normalized by the pooled standard deviation. What d = 2 means in concrete terms is that an average man can throw faster and further than ~98% of women.

It’s surprising to me that throwing isn’t more instinctual. If not taught how to throw, people will generally throw things by extending their elbows from their chest. This is “throwing like a girl” though it doesn’t really have anything to do with gender except we teach boys how to throw things.

I wonder when the common overhand throw was first tried out. Presumably, it was an evolution, but Id guess the first attempt was more of a fling...

neat! i studied the related phenomenon of locomotion by swinging and we postulated that elastic energy storage (and release) in the shoulder was an important part of the energetics and efficiency of that form of locomotion.

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