four legged run

beaureqard  asked:

you characterized human walking as controlled falling--does animal walking take more effort because they have 4 legs, they have to push off each one? what about the relative stresses of human vs animal running? is there an example of a well-muscled animal that doesnt have such trouble with fragility, or a social animal that can care for wounded members of its group? we've sort of gotten away from anthropology huh lmao Sorry! I guess... what pressures selected for the above in humans?

Actually, a lot of this is still anthropology! Bipedalism- one of the defining characteristics of hominins- and its origins are extremely important to physical anthropologists and primatologists.

Human walking is divided into two parts: stance phase and swing phase. As an experiment, stand up, take a slow walking step, and really think about what you’re doing. Then sit down again because things tend to get weird when you actually think about what you’re doing when you walk- it’s kind of like remembering to breathe or being aware that you can feel your tongue in your mouth. By and large as a species*, our brains are so used to the motions of walking that thinking about it can throw us off our stride. This is why learning to walk again after an injury can be so challenging- actively thinking about locomotion is not something the human brain likes to do. To walk, we pick up a leg, swing it forward, land on it, roll off the toe of the other leg, pick it up, swing forward, land on it… it goes on forever. Here’s an illustration of what that looks like!

This doesn’t actually require a lot of energy, from a caloric standpoint. It’s just falling with style. Running is quite similar; it’s just more energy put into it. It’s still the same motion; the leg just gets lifted a little higher. There’s a phase where both legs are off the ground (which you can’t see in this gif, unfortunately)- same as when a horse moves from walking to galloping. 

 Let’s compare that to a horse- the first gif is a horse walking, the second is a horse galloping.

Much of the stress in four-legged running comes from body weight; a horse is going to be a lot heavier than a human, so that’s a lot of force put on the knees. Running is always going to be more stressful than walking, but for humans, our relatively small body size is going to make it comparatively less stressful and more efficient.

Now, this isn’t to say that other animals aren’t efficient for what they are/can do; it’s just to say that we’re more efficient. There’s only two animals that can really keep up with us: domesticated dogs and domesticated horses. We’re going to keep looking at horses because horses and the energetics of their movement are really well-studied; horses have had a long working relationship with humans. Unlike most other animals, it’s unlikely we domesticated them just to eat- equines are real dynamos and are able to do a tremendous amount of work. Now, this is where things kind of get into physics, but bear with me for a moment. Consider for just a second: animals (us included) as machines. There’s an input: oxygen and calories. There’s an output that we call “work,” which is using a force to move an object a distance when both the force and the motion of the object are in the same direction. That’s what we mean when we’re talking about “work,” the ability to move an object (at bare minimum, the animal’s body) a distance. Horses have been selectively bred over millennia for stamina and speed, and as a result the domesticated horse’s maximum work output is about 3.5 times higher than what it should be**. So back to that question of two feet versus four feet: It’s not just about quadrupedalism versus bipedalism, but also about aerobic potential, lung capacity, metabolism… there’s a lot to it

Efficiency versus the capacity for speed is one of those evolutionary tradeoffs. There’s quite a lot of them in locomotion, including the fragility of various species. Horses and other leggy ungulates are typically more fragile than most other quadrupeds. If we look at predators- let’s use coyotes as an example- they might not be as fast initially as an ungulate, but they’ve also got some padding around their ankles. They’re less likely to shatter a bone. Bigger carnivores, like lions? Even more padding, with hunting strategies to match. Lions like to chase their prey into ambushes rather than just chase it down. To escape these ambushes, prey species need speed; like all things evolutionary, those fragile legs are a tradeoff. 

As far as social animals caring for wounded members of their group, you’ll sometimes see this in other primates- they’ll lick each others’ wounds, pick off debris, that sort of thing. There’s some evidence that they’ll chew plants with medicinal properties, but interpreting these actions is really difficult because there’s so much we don’t know about great apes’ cognition. There’s an excellent book, The Evolution of Sickness and Healing, that has loads of information. While it’s a little older- it was published in 1997- it’s a great jumping off point. The whole thing’s available for free online here. Chapter 2 in particular has a lot of good information on what chimpanzees have been observed doing, including one of my favorite Jane Goodall anecdotes about a 23-year-old male chimpanzee (so, an adult) who got hurt in a fight with another chimp and started screaming; his elderly mother came running from about half a kilometer away and started grooming him, which got him to calm down. Even for chimps, mom’s attention can make it all better. 

As always, footnotes and references/further reading under the jump!

Keep reading

I’ve seen a few posts about people watching centaur no nayami, and coming to the conclusion that the political sub-plot is about how “SJW culture has gone too far!” and I guess from what we’ve seen in the anime up to this point that’s a valid argument, and is maybe even where the anime intends to go with it

But in the manga the message was very clear– Himeno and her friends may live in a society that SEEMS like it’s “SJW gone bad”, but in reality the characters still experience microaggressions and have to deal with race issues, except they CAN’T, because it’s considered bad form to discuss these things

Like in one chapter, Himeno (a centaur) has an old woman complain about all the space Himeno is taking up on the train, and when Himeno’s friends jump in to say “hey that’s not a nice thing to say” ALL the adults on the train gang up on these girls and are like “kids are SO SENSITIVE these days”

It’s clear that the message of the manga is less “the world is too politically correct” and more “we’re tired of talking about racism and discrimination so let’s just say everyone is equal and punish people who say discriminatory things without explaining why they’re discriminatory, and therefore we can just pretend we live in a post-discrimination world”

Himeno and her friends DO talk about real, physical differences between each other, though, and acknowledge that just saying “everyone treat everyone equally!” isn’t really all that helpful, because different people have different needs, and if you make every kid run the same amount of laps, but some kids have four legs and can run faster, then that’s not really treating everyone fairly

And they do have some basic accomodations (like merpeople living in schools that are partly submerged in water) but I don’t think the government of centaur no nayami provides those accomodations out of the good of their heart: rather, they just want to keep the peace

It’s shown that there have been major social justice movements in the past, and I think the whole “everyone is equal now yay!” aspect of the show is just the government trying to quash future protests

So I hope the show continues to work off the manga’s message, because schoolgirl shenanigans aside, the series had a lot of interesting messages about modern society, and how we deal with issues like racism and accessibility – basically treating them as solved instead of allowing ourselves to have honest, deep conversations about the complexities of these issues

anonymous asked:

"I'm all in if you're all in, baby"

You pace around the studio as your boyfriend records for his second solo album, your nerves pulsating rapidly as you do your best to come up with a speech, a speech that will stop him from terminating the relationship as you tell him in great detail that you have been offered a position in a California Hospital, permanently. You overhear the door open and close, you turn on your heels, your eyes instantly meeting the only eyes that still bring butterflies to your stomach,

“The last time yeh visited me here you brought me a puppy you impulsively decided to buy, so what yeh get us this time?” Harry’s voice chuckles, finally causing you to take a breath and grin. 

“Just came to see you,” You smile while he places a tender kiss on your cheek, followed by pulling you in for a hug, his arms wrapping around you.

You carefully pull away from his warm embrace as you see one of his songwriters walking in, “So, no puppy?” Harry questions with a small pout, making you think he wants to have another four legged friend running around the house chewing on his shoes and belts. 

“No, we can talk about that later.” You trail off, your heart beginning to race at the thought of now bringing up what you are incredibly eager and nervous to tell him. 

Keep reading

Lil_Queen prompted on AO3: “Can u do one where mangus saves max life, and one where mangus is using a seraph blade. Thanks”
Alright, writing this has clearly proved that I can’t write fighting scenes, no matter how hard I try. But I tried really really hard, I promise! Also, BAMF!Magnus is, like, everything to me.
Shout out to @rai-knightshade and @nickkibubbles for picking Magnus+Seraph Blade and Max sr.!

A spear crashes into the energy barrier and it’s like a thunder against his bones.

He falls to the ground, knees hitting the pavement, and he gasps as the air leaves his lungs. There’s dirt under his fingernails and on his clothes, there’s mud under his shoes. It’s so dark he can barely see, cat eyes glowing golden with the magic that’s dying in his fingertips.

Keep reading

Puppy Love (A Bucky Barnes One Shot)

Pairings: Bucky Barnes x Reader

Word Count: 873 (so short compared to my usual writing lol)

Warnings: puppy hate (lol)

(A.N): Hello! Here I am, 3 months later with my second one shot out of the 3 I wanted to write (the first one shot linked here). Hopefully you enjoy this one shot of Bucky! (This was a little rusty, so I apologize!)

It was 3 in the afternoon when Bucky arrived at his apartment. The air seemed… a bit unfamiliar to him. It was as if something was off about the place. An unfamiliar smell hit his nose and he scrunched it in response. Unbeknownst to him, there was a stranger in his home. Bucky shouted your name but to no avail. Suddenly, a pair of four fluffy legs comes running down the stairs and jumps onto Bucky’s legs. Bucky’s terrified! His initial reaction was to kick the thing begging for his attention, but as he looked down into the 4-legged thing’s eyes, he sees that it is a puppy. A fluffy puppy… the type of puppy that he never wanted to have. He managed to shoo away the dog and his fear was soon replaced with slight anger.

Keep reading

We’re all set for our holiday party tonight with these ridiculous beer and wine labels featuring - who else?! - the four legged kiddos that run this household! 😜 Big shout out to @pinholepress for these custom labels. We’ve worked alongside @pinholepress for a handful of years now, and we keep going back and sharing the word because their printed products are top notch AND super affordable. Basically, they’re the best. 👌 #beerme #pinholepress #holidayparty by yellowbrickhome

[Corinne is out for a run in the Tillamook Forest; a four-legged run. She’s learned to control when she transforms–for the most part–but it’s the actual ‘being a wolf’ part that she still has a hard time controlling. After a few hours of exploration, Corinne makes her way back to the tree where her bag of clothes is buried.]