Speaker 1

(00:00) 📋 Thanks to Linode for supporting this episode of SciShow.

You can go to linode.com slash SciShow to learn more and get $100.60 day credit on a new Linode account. Imagine a child skipping down the sidewalk, swinging their arms as they bound along.

Kids skip a lot and make it look practically effortless. But as we age, most of us stop skipping. It takes a lot of energy, and it's just not a practical way to get around.

But across the animal kingdom, there are other animals that skip, and not just when they're young and developing. They show us that skipping isn't always impractical. Sometimes this whimsical movement is a pretty decent way to get around.

Animals have all sorts of ways of getting from A to B. We humans are a little unusual in that we walk on two legs, so we move differently from many species. But like us, many animals can move around on just two legs.

And a lot of them can also walk, run, hop and jump. For some animals, though, these options don't offer an efficient enough way to move as fast as they need to. And that's why some of them turn to skipping.

Just like running, skipping is a faster way of getting around than walking. But for us, it takes about 24% more energy than running at the same pace, so it doesn't make a whole lot of sense. But for certain primates who aren't as specially adapted to walking on two legs, skipping can actually be pretty practical.

Now, when I say skipping, you're likely picturing the motion of a young child bounding along with a spring in their step. This movement is technically known as bilateral skipping, because the lead leg alternates with each stride. So you push off with 1ft in front, then the other, and so on.

We may be the only animals that skip exactly like this, but there's also unilateral skipping, where the same foot stays in front the whole time. And this is the kind of skipping we tend to see in other animals. For instance, over in Madagascar, our relative, the lemur, will often get up on two legs and skip across the ground anytime it needs to cover some distance quickly.

The reason these primates skip much more readily than adult humans probably comes down to skeletal differences. Since lemurs evolve to walk and climb with four legs, when they do get up on two legs, their high limbs don't straighten and stiffen the way human legs do. With their knees and hips always slightly bent, they can't produce the same amount of force when they run as we do by fully straightening our legs.

So skipping can be a better way to move fast. Plus, unilateral skipping is actually more stable than running at the same speed, because the body spends less time supported by just one leg. And for an animal that's not well adapted to moving on two legs, stability is likely important.

So it's no wonder lemurs seem to prefer skipping to running. But there are skippers in other parts of the animal kingdom, too. Like birds.

Bird's center of gravity is dramatically different from ours, and their legs and hips are positioned in a way that makes bouncing movements easier than running. Little songbirds are light enough that they can just hop around easily enough, but larger birds, like crows and magpies, often skip when they need to get across the ground quickly. It might not be more efficient than running, but it's a more stable way of getting around for about the same cost.

Out in the deserts of North Africa and Asia, there's another skipping animal known as the jerboa. This two legged rodent mostly gets around by hopping. But when evading predators, it mixes things up by running, skipping, and changing direction.

Since it lives out in the open sand, where it's hard to hide from predators, these erratic movements may help jerboa avoid getting caught. Unlike for us humans, skipping just makes sense for all of these animals because they're built differently. We're just not made for skipping here on Earth.

But there's at least one place where skipping might be practical for humans, and that's on the Moon. When Apollo astronauts walked on the Moon, their stride often naturally turned to a skip. It's easier to skip in low gravity, and NASA scientists hypothesize that astronauts may have preferred this type of movement because of the stability it offered here on Earth, scientists have simulated low gravity conditions by putting participants on treadmills while they were partially lifted by harnesses.

Analysis of their movements suggest it was easier for them to skip than to run. The sample size of this study was small, as is the number of astronauts who have walked on the Moon. But computer models have backed up the idea that skipping on the Moon may be practical.

On the lunar surface, you can skip for about the same amount of energy as it takes to walk on Earth, and you'll be more stable. For most of us non-astronauts, skipping will still never be practical unless you're looking for a good workout. Skipping burns more energy and is thought to be easier on the knees than running.

So if you ever feel inspired to embrace your inner child or your inner lemur or your boa, go for it. You're never too old to go for a skip, but don't skip the ad read, because this SciShow video is supported by Linode, an award winning cloud computing company. Even if you're not familiar with the terminology, you probably have tons of experience with cloud computing.

It's where you keep your files, send emails, watch videos, and do a lot of your online stuff. The cloud lets you innovate faster and keep in touch with collaborators. It gives you more time away from managing It hardware so you can focus on your projects themselves.

Ultimately, Linode gives you the freedom to get your job done. Whether you're looking for something to propel your small startup into the next stage of success, keep your nonprofit on track or manage your global corporation. Linode's cloud computing tools can help to explore what the cloud can do for you.

You can click the link in the description or head to linode.com SciShow for $100.60 day credit on a new Linode account. Thanks for watching and don't forget to be awesome.