Saturday, August 18, 2012

Weekly Science Roundup #7

This week, we have three stories that are somewhat surprising and somewhat controversial in nature.

1. Ichthyosaurs got the bends?


While it may seem almost ridiculous, ancient marine reptiles suffered from the same condition human divers can get: the bends.

These reptiles lived in the water, 24/7. So why the bends? Well, interestingly enough, the earliest ichthyosaurs didn't seem to have this problem. It wasn't until later, near the end of the Jurassic and into the Cretaceous periods that this issue cropped up. There are a few ideas out there as to why.

Perhaps they were getting chased by scarier (faster, more evolved) predators later on, moving quickly from the surface to the deep to escape. The pressure changes could've forced the nitrogen in their lungs to dissolve in their body, and surfacing again would've formed the nitrogen into the painful internal bubbles divers dread. Another idea is that they just dove deeper and deeper as time went on, but never evolved the ability to deal with the nitrogen like modern whales have.

No matter what happened, it's clear from scarring on their fossilized bones that these animals really did get the bends. Some scientists even go so far to say that the bends could've contributed to their eventual extinction, though I'm not sure how serious they are.

Speaking of "are you serious?" scientists...


2. Neanderthals and Humans Interbred - no wait they didn't - no wait they did - no wait -


According to a new study, humans and neanderthals didn't interbreed (despite overwhelming recent evidence that they did).

Now, I don't mind people trying to prove stuff wrong in science. In fact, I encourage it. That's what science is all about. But this study? Ehhhh...no. I'm not convinced.

First of all, Discovery News and all other media outlets reporting on this: your article titles need some work. So do your articles, frankly, in this case. You report this as if it's conclusive evidence that neanderthals and humans didn't have children together, when in fact this does not prove that at all.

What this study actually shows is that a computer model demonstrated another way for the percentage of "neanderthal DNA" that exists within modern humans to have gotten there (rather than from interbreeding). They suggest it's all from our last common ancestor with neanderthals, something that was still considered...a couple of years ago .

Unfortunately for those who did this study, we've got loads of new data now with the genomes mapped. There are dozens of reasons the conclusions of this study just don't hold water, and the take-away message is that the modeling this study did is outdated. Thankfully, at least Nature News has updated their article to reflect this.

So did neanderthals and humans interbreed? Our best evidence still suggest that they did. Studies like the one being reported all over the place right now just don't take enough of the newest empirical evidence into account. Yet they get all hyped up anyway and confuse the general public.

Oh well. While the general public might not be well versed in the nuances of genomics, they can at least do a pretty great job at reporting on the threats facing various species in our country...


3. Citizens get species on Endangered List that government agencies miss.


Thanks to U.S. citizens, animals are being protected that would've otherwise been ignored by U.S. Fish and Wildilfe Services. 

This is really neat and shows just what people can accomplish when they push to save their non-human neighbors.

A study showed that animals in the Endangered Species Act that got there through citizen petition, rather than through appointment by the FWS, were more likely to be "in the way" of developing land. The FWS tries not to step on too many toes, but citizens don't hold such qualms. Also, the species nominated by citizen petition were significantly more threatened, on average, than those nominated by the FWS. Essentially, many species are only on the list today thanks to the initiatives of every-day people.

This should (hopefully) stop people from halting citizen reports of threatened species, as certain politicians have tried to do. This is clear evidence that citizens are a valuable part of the identification and protection of endangered species in this country.

Go citizens, go!



NOTE: I will be on blog hiatus until the end of August, as I'll be camping for several days between now and then, and also need to concentrate on wrapping up my current WIP novel. Thanks for understanding, and I'll see you in September!


Wednesday, August 15, 2012

Pluto isn't a planet and WriteOnCon changed my novel's first pages.


So I had a great experience at WriteOnCon this week. (WriteOnCon is an online conference for children's book writers, for those not in the know.) At first I wasn't sure what I could get out of an online conference, but it turns out the answer is a lot!

The livechats and vlogs were all fascinating, but I personally got the most out of the forums. That's where I was able to post my query letter and first five pages of my novel and get them critiqued by random (awesome) strangers.

After a day of review by others, something was clear to me: my opening 2 1/2 pages needed to be rewritten. Almost entirely. I was shocked. Shocked, because I had worked my novel to perfection months earlier. It was the best I could write it. And before that, I had worked it to perfection last year. Again, to the best I could write it. And the year before last year, I had done the same thing.

Huh. Noticing a trend, here.

Could it be that the quality of my novel decays over time as it sits on my hard drive? I think it's great, and then a couple months later it's gotten all gross and soggy, with mold spores galore?

Or...perhaps I've just become a better writer over time. Perhaps as I learn more and apply that knowledge, it forces changes onto things I thought were pretty set as they were.

Hmm...

As a scientist and a fiction writer, I can't help but notice things those two professions have in common. By spending time studying and experimenting, we grow in our knowledge, whether scientific or literary.

Pluto was "demoted" because we learned more about its part of space. Turns out, it's just one of over 200 icy objects orbiting the sun out past Neptune (known as the "Kuiper Belt"). Since it hasn't turned all those things into its moons, it hasn't successfully cleared out its orbit neat and tidy like a planet should. Planets must have enough gravity to boss around anything and everything in their particular orbit around the sun.

Pluto doesn't do that. We didn't know that before 2005, because we didn't know all those other tiny icy things existed. We just plain didn't see them before then.

Whoops. Well, at least Pluto is finally grouped where it should be! Congratulations on finding your true family, Pluto!

Likewise, my first few pages of my novel were scrutinized closely by myself and my critique group over and over. They changed many times, but finally settled out into awesomeness...

But that was back in 2011. Back before I learned how to see the "tiny icy things". Back before I knew what I know now.

So it was time to make changes. I realized that this week and worked tirelessly to revise my first few pages. At first, I hated the changes. I resisted. It wasn't how it used to be. It wasn't the opening I had memorized from reading it out loud to myself on repeat so many times. This is what I like to refer to as my "PLUTO IS STILL A PLANET YOU GUYS. STOP BEING MEAN TO PLUTO. GOSH." mentality.

It's a silly mentality. Once I set my stubbornness aside, I was able to spend two straight days crafting a wonderful new opening. An opening that demonstrated my protagonist's character and conflict neatly and clearly. An opening that fits with how the rest of my entire novel reads.

Pluto found it's rightful category in space, and my book just found it's new rightful opening.

Thank you, WriteOnCon.

So what does the future hold? Will my first pages stay the same forever? Almost certainly not, no. Will Pluto remain categorized as a Dwarf Planet? Honestly, probably not. We'll change that around as the need for new categories emerges in the future.

Science and writing are both about adaptability. When you learn something new, you apply it to the old and change it. Update it. Help it make more sense.

Maybe that's why I love them both so much. They've taught me the beauty of change. 

Tuesday, August 14, 2012

1470



This is a really big deal, guys. This is a specimen that's been argued about for decades. Now, they've found other members of its species!

1470 (left) and 1813 (right)
As a paleoanthropologist, this has got me geeking out like you wouldn't believe. This is personal for me. My very first paleoanthro project in college was demonstrating that this skull could not physically be a male Homo habilis, because its features were more feminine for its size than little H. habilis 1813's features were. And not just by a tiny bit. By a LOT. Back then I had a blast measuring gorilla skulls (where sexual dimorphism - the measurable, physical differences between the sexes - runs rampant). Oh, the days when spending countless grueling hours with digital calipers and old bones seemed novel...

Anyhow, I demonstrated that even the most sexually dimorphic ape species didn't come close to what we'd need to assume about 1470 and 1813 to get them to belong to the same species. However, my study was just a measly undergraduate project and didn't garner any attention other than an impressed eyebrow-raise from my esteemed professor (you have no idea how much I geeked out about that eyebrow raise).

The point of sharing this story is that I HAVE BEEN WAITING A LONG TIME FOR SOMEONE TO PROVE FOR REAL THAT 1470 IS NOT HOMO HABILIS. 


And the only way to truly prove that was to find more fossils. That's what has finally happened. A whole slew of new fossils have been discovered. Holy cow. They match 1470 perfectly and show that it's significantly different from other specimens (compared to others, 1470 and these new fossils have a different shaped jaw with canine teeth facing the front and a flat face).

These fossils come from Koobi Fora, a site of fossil beds on the banks of Lake Turkana in Eastern Africa. This is the same place 1470 was found, and is also where specimens of Homo habilis and Homo erectus have been found. It seems likely that at least three species of early humans lived in the same place at the same time.

That's awesome.

Each was just different enough that they probably occupied different environmental niches in the same location, like modern primates do so often today. But it begs the questions...what did they think of each other? Did they interact at all?

These were early versions of us. While they didn't have complex tools or real language (we don't think), they still were smarter than anything else around them and were likely self-aware. What was that like for them? Hanging with other species of, essentially, themselves?

This is why I love paleontology. It's arguably the most imaginative of all the science fields.

Now, please excuse me while I go back to daydreaming what it would've been like to hang with all our early ancestors 2 million years ago...and congratulate 1470 in person on finally being recognized as its own species and not just a freaky version of Homo habilis.

Saturday, August 11, 2012

Weekly Science Roundup #6

Lots of exciting things going on in science lately! I've already geeked out on here about Curiosity's landing on Mars. The newest finds in human evolution warrant their own post (I'll dive into that early next week). So for now, have a few stories that may have fallen through the cracks, but deserve time in the spotlight!

First up, a Mars story that has nothing to do with the new rover.

1. PLATE TECTONICS ON MARS


Holy moly, they've (probably) found plate tectonics on Mars.

For those less geologically geeky, plate tectonics is the motion of chunks of a planet over its inner mantle and core. Earth is naturally divided into seven big plates and a handful of smaller ones (imagine an eggshell with cracks), all slowly moving about and causing fun things like earthquakes.

It now appears that Mars may have at least two plates of its own. This is the first time we've seen evidence for plate tectonics beyond our own planet. Geologist Dr. An Yin has noted multiple peculiarities on Mars, including a linear volcanic zone and a super long series of canyons, that are most easily explained if Mars truly has fault lines. And if you don't already know, science prefers the simplest explanation for things.

Interestingly, it seems that Mars's plate tectonics are much less developed than those of Earth. This could be a cool chance to explore what early plate tectonics may have been like on our own planet.

Speaking of early things...


2. EARLY RODENTS GIVE CLUES TO FIRST GRASSLANDS


New fossils in South America suggest that grasslands may have been around 15 million years earlier than previously thought. 

The two new fossils that have given rise to this controversial idea are both rodents: Andemys termasi and Eoviscaccia frassinnetti. The former is an early relative of agoutis, and the latter a relative of chinchillas. They're both dated to be 32 million years old.

So why do these two rodents imply that grasslands were around way back then?

The answer is in their teeth. Both have an adaptation known as hypsodonty: their back teeth have enamel that extends below their gums. This is, in modern times, used by animals who eat tough grasses. Does this HAVE to mean these 32 million year-old rodents were thriving in grasslands that aren't supposed to have shown up on Earth for another 15 million years? Could it have originally evolved for something else? Maybe. But so far, no one can think of any other plausible explanation. It's likely time to revise when grasslands first appeared on our planet.

I love when stuff like this happens. Science! We're always learning new things and overthrowing old ideas when better evidence surfaces.


3. PERSEID METEOR SHOWER PEAKS TONIGHT


I'd be remiss if I didn't mention in my last slot that the Perseids are going on this weekend. This is an annual meteor shower that occurs every August when Earth passes through the section of our orbit where the comet Swift-Tuttle crosses. The meteors are actually debris left behind by the comet. We pass through that debris and as the rocky chunks careen through our atmosphere, they compress the air in front of them.

Just like rubbing your hands together creates heat through friction, the space rock heats up the air in our atmosphere as well. Heat and pressure combine to essentially set the air on fire. Light and heat are produced, making a streaking fireball appear in the sky.

If you're looking to catch this cool show, you want to look Northeast tonight (if you live in North America) around midnight. You'll probably be able to see the shower anytime tonight, but the best viewing will be in the early morning hours. Be sure to find someplace free of clouds and light pollution! Us folks stuck in the big cities are usually out of luck for any decent views.

Best of luck!

Thursday, August 9, 2012

Science of the Olympics: Muscles

So we've seen how humans are able to run, swim, and flip about, but why can we even move our muscles in the first place? That is the subject of my final post in this Science of the Olympics series.


The Science of Muscles

Muscles work through a series of contractions. The source of energy for these contractions is a mix of oxygen, glycogen (a carbohydrate), and fat. Those things come together and react to produce ATP (adenosine triphosphate). ATP powers our muscles. 

In other words, fats and carbohydrates react with oxygen to make a substance that helps energy get into our muscles. 

Not actually all too complicated an explanation at first glance. I won't go into the nitty-gritty details that make it more complicated here. Just know that when you move, you can thank ATP.

Anyhow, there are two main types of muscle fibers: fast twitch and slow twitch. What's the difference? Pretty much as it sounds. Fast twitch contracts faster, slow twitch contracts slower. In addition, slow twitch  contracts for longer periods of time than fast twitch. Interestingly, endurance runners (like marathon runners) have more slow twitch fibers than fast twitch. It's not clear if humans can actually change one type of fiber into another, so it may just be that they're born with more of those fibers, giving them the ability to keep their muscles going for longer periods of time. 

Lucky them!

Now, to let any of these muscles fibers work at all, we've got to get them ATP. And to make ATP, we need oxygen. 

How do we get oxygen to our muscles? Our blood of course!

The human heart pumps, on average, five liters of blood per minute at rest. That number increases during exercise. 

The heart pumps your blood in two ways. On one side, it pumps blood out towards your lungs. That blood rushes around outside your lungs, capturing oxygen from your alveoli (lung air sacs). It then takes that back to the heart. This is where the second pump comes in. This time, your heart pumps the fresh, oxygenated blood out towards the rest of your body, instead of just your lungs.

And that's how it gets to your muscles. Now, during exercise, your body tries to optimize blood flow to your muscles. That means it dilates the blood vessels in your muscles (for more blood and oxygen), increases your breathing rate and depth, and diverts blood away from places that don't need it as much (like your digestive track). Olympian bodies are doing this constantly. 

They're also pumping blood out of their hearts much faster than the average person does, and squeezing their hearts harder, too. This gets lots of oxygen to the body, but also means that the lungs have to deal with much bigger "blasts" of blood heading their way each beat. Physically fit people have lungs with blood vessels that can dilate well enough to handle the increase in blood flow safely. People who aren't as fit and try to do something active, resulting in this type of extra-blood-pumping situation, won't have vessels that can handle it. That's what causes high blood pressure.

Finally, physically fit people can take in more oxygen during each breath. Such people have more alveoli available in their lungs, thanks to (safe amounts) of increased blood pressure. That means more places to gather oxygen! More oxygen means more ATP which means more muscle energy. More energy can result in amazing things, like all the broken world records we've already seen at the 2012 Olympics.

So that's the short version of how our muscles work. It's pretty neat to think about all the wacky things that happen in our bodies every instant that we're entirely unaware of, isn't it? Especially when we realize how these little things add up to give us the ability to run, jump, and win gold medals. 


Thanks for following along with me over the past two weeks as we've explored the Science Behind the Olympics! Perhaps there will be a blog series revival in 2014 with Sochi. After all, we've barely skimmed the surface of the science involved in these great games.


Monday, August 6, 2012

Curiosity Has Landed!!!

Late last night, I woke up at 1:20 am to watch with JPL and NASA as we waited for Curiosity to get through its seven minutes of terror and report back via Odyssey (a satellite around Mars). It was heart-pounding. The wait was excruciating. Every little announcement of Curiosity's progress brought cautious, shaky smiles. But the tough part hadn't happened yet. It hadn't touched down.

And then it did.




I literally burst into tears and shrieked so loud that my cat ran into the room to see what in the world had gotten into me.

Setting my alarm to ensure I'd get up and see this live with everyone else was the best decision I could've ever made. The video above doesn't show the several minutes prior to the landing, where everyone is sharing in panic, but it does show the explosion of joy that people in that room and around the world shared together at the same moment. It also doesn't show the repeat of the celebratory screams and shouts as the very first picture arrives of Curiosity sitting on Mars. (I burst into tears again when that came in. Not at all ashamed to admit it.) It was amazing to be a part of that emotional rollercoaster.


Who says we're past the days when space exploration can be inspiring? Who says no one really cares anymore?

I was on Twitter last night with thousands, if not millions, of people all watching this same event, all celebrating this landing.

This was the most inspiring thing I've witnessed in a long, long time.

We did it. Humans did this. We sat down and put our minds to it, and we landed a massive science laboratory on a planet millions of miles away without it breaking. This restores my faith in us as a species. We can actually use these big brains of ours to do something not only non-violent, but something that allows for greater learning.

I love science. And I love the people who devote their lives to it. There's a child-like innocence left in us, and this is where it shows up the best. Congratulations, JPL and NASA. This entire feat is beyond amazing.


EDIT: Friend found a video of ten whole minutes surrounding the landing, so if you want to get more of a feel for what was happening last night, watch here!

Sunday, August 5, 2012

Curiosity!

Today's the day. Well, sort of. In my time zone, tomorrow's the day.

Anyhow, Curiosity will be LANDING ON MARS very soon. 1:31 am, August 6th, Eastern Time. Happy birthday to me! (Really. That's my birthday. Best present ever.)


Those interested can watch, live, on NASA TV. I'll be watching. Haven't decided yet if I'll go to bed early and set an alarm to wake me up after 1am for the event, or if I'll just stay up that late. In any case, we won't know if she's landed properly for several minutes afterwards, because the signal takes a while to travel through space. We might not even find out tonight at all, depending on several factors.

I cannot stress enough how super exciting and super scary this is. We're dropping a mobile science laboratory the size of a car onto another planet. Whoa. Just let that sink into your brains for a second.

Best wishes to the MSL team, all of NASA, and of course, Curiosity herself. The world will be watching with fingers crossed.

Friday, August 3, 2012

Science of the Olympics: Legs

As track and field begins at the Olympics, the focus shifts off of the extremely flexible and switches to the extremely fast. 


But how do we move so quickly? It all comes down to adaptations of our hind limbs, millions of years in the making.

The Science of Legs

We take for granted our ability to move around on two legs, but it's kind of a big deal. Almost every other land animal runs on four legs, not two. I say almost, because there are notable exceptions...

But we are the only animal that runs on two legs and has no tail to act as a balancing mechanism. This requires some specialization.

Interestingly enough, it was by losing our tail that we were first able to frequently assume upright postures. All those muscles that used to control our tail were re-purposed to hold up our guts. Really.

Our pelvis sits at the bottom of our torso and without those muscles there, our guts would just fall through our pelvis. Gross, yes, but true. The muscle is what holds everything up, and we wouldn't have that if we still had those muscles going out for our tail.

(Why does that Utahraptor above not have this problem? Well, honestly, they don't stand like we do. They aren't "upright"...they don't have their pelvis rotated like ours for that problem to even exist.)

Humans aren't the first primates to have this issue. It's actually an issue for all apes. One big thing about being an ape, is that we tend to sit in upright positions, freeing our hands to manipulate objects. That's the leading theory as to why our tails shrunk up and disappeared over generations in the past.

But being upright is just step one on the way to running on two legs. Next, we had to somehow change from moving around with help from our hands, to moving solely on two feet.

Other apes walk on two feet. Some quite frequently. But no other ape can walk only on two feet all day, every day. That's the realm of humans.

The switch to bipedalism (two-legged walking) meant that we needed to rearrange some muscles and change the shape of some of our bones. There are countless changes that took place over millions of years and I obviously don't have time or space in this post to go into them all. Therefore, I'll just concentrate on two big changes: the rearrangement of our gluteal muscles and the change in our foot bones.

Gluteal muscles help keep us standing upright. They pull us back up when we've jumped and are trying to re-straighten our bodies. Gluteus maximus pulls our thigh back from a bent position at the hip. Gluteus medius and minimus help us stay steady standing on one leg. They tighten on the outer edge of our leg to keep us from buckling in, since our center of mass is in the middle of our bodies and being on one leg makes it hard not to fall inwards towards that.

In other animals, these muscles are smaller and less important. Gluteus maximus in particular is barely existent in most other species. They're essentially just muscles that rotate the thigh, so for most animals, they don't need giant muscles to help with that. But we do. And that's one of the major changes that had to take place to make bipedalism possible (and comfortable!).

The other big change was in our foot structure. Instead of having an opposable big toe like other apes, ours is in line with the rest of our toes. In addition, we've developed an arching pattern in our foot bones. This major change helps conserve energy while walking and running. Instead of having our weight go from the heel, through the center of the foot, and out through the center toes upon lift-off, our weight transfers from our heel, through the outside of our foot, to the ball of the foot, and out the big toe which is better at supporting the weight.

So that's a bit of explanation of what it took to get us on two legs. But how did we start running on two legs?

That's where tendons come in. We've got some pretty amazing tendons in our legs, rivaling those of freaking antelopes. Particularly our Achilles tendon. It's huge. These tendons act like rubber bands, springing us forward and yanking our legs back into place for the next step. Rearranging bones and muscles might have started us walking on two legs, but it was strengthening the tendons that got us running.

But why? Why did we change to start running? We aren't really that fast, compared to other animals. The scary cats could easily chase us down to eat us, so what did all this running help us to do?

The leading idea is that it got us meat. Maybe we couldn't out-sprint the things hunting us, but we could out-last the things we were hunting. We aren't cheetah-fast, but boy can we ever run marathons. Humans are great at running consistent speeds over long distances. Humans still do this today to catch food. Hunters chase down their prey for hours and hours, tiring out the animal until they can't move any more. Then we strike.

It's one idea, at least. Though, I'm pretty sure catching gazelles isn't what most of the Olympians will be thinking about during their runs over the next few days. That's the coolest part of all of this, in my opinion. Taking things that evolved to help us in one way, and applying them in a brand new way. Just like typing on this keyboard right now. My fine motor control did not evolve to let me write blog posts, but that's what I get to do with those skills in the modern world.

So the evolutionary story continues.

PS: For those curious and wanting more information, here's a great article about the evolution of running. 

Wednesday, August 1, 2012

Science of the Olympics: The Shoulder

Between USA gold in women's gymnastics and Michael Phelps swimming his way to the most Olympic medals EVER, there's been a lot of attention on gymnastics and swimming lately.

But how do they flip around like that? How do they swim so fast? What's going on?

Getty Images
Both sports (not to mention the image above) have one thing in common that make them possible: our amazing shoulder joint.

The Science of the Shoulder

Our shoulders allow for a near full-range rotation of our arms. Go ahead and swing your arms around for a while. Reach up over your head. Stretch out backwards behind you. Congratulations, you're an ape.

Monkeys (with the exception of spider monkeys, which have a similar range of motion thanks to convergent evolution) can't do this. They can't reach straight up over their heads. They can't stick their arms out to their sides and behind their backs. They can't even do monkey bars. They aren't apes (and apes aren't monkeys, just to be clear).

But how do we, and our fellow apes (chimps, gorillas, gibbons, bonobos, and orangutans), do this? To answer that, we need to look at the bones.
See, when you want lots of flexibility, you need a large surface area at the joint for unhindered movements. 

What you see below is a top-down view (or "proximal" view) of the humerus of a monkey (baboon) and an ape (human), via eskeletons.org. This is the end of the humerus that would come into contact with the scapula (aka the shoulder blade). It's known as a ball-in-socket joint.


The left picture is from the baboon, the right from the human. You can immediately see the difference in surface area for the contact zone. If you trace the length of the smooth, curved edge, you'll see that the baboon only has a smooth zone around about half of it's end, while the human one extends nearly two thirds. Plus, the human's humeral head is all around larger than that of the monkey. More surface for the humerus to slide around in the socket of the shoulder blade = more range of movement.


Again, on the left we see the baboon humerus. It's easy to see from this side view the difference between the humerus head of the monkey versus the human (on the right). The head of the human humerus is much larger and rounder, a much better "ball" for the ball-in-socket joint.

Another thing to point out is how curved the monkey humerus is compared to the human's. The straightness of the human arm allows us to hang from things safely. To understand this, you just need to think about the tension. The straighter the bone, the less likely it is to break from tension stressing its curves.

But why do we need any of this? Why did we end up with super flexible shoulders and this ability to hang from stuff? Evolution wasn't exactly working to allow us to flip around like acrobats...or was it?

Actually, it was. Hanging from trees (or "suspension") is a great adaptation. It gives us the ability to move along a branch and take advantage of more area around us: everything above the branch (by sitting on the branch like a monkey) and everything below the branch (by hanging under it). That means more food!

Brachiating, or arm-swinging from branch to branch, was just the next step. Instead of having to climb back to the trunk of the tree, climb down, and climb back up another tree, it's easier to be able to move from tree to tree up in the canopy. Monkeys tend to do this by leaping between trees. Apes don't have tails and tend to be heavier, so leaping between trees is trickier for our balance. That makes it's safer to be able to reach an arm and pull oneself towards the next tree. Do that over and over, and you end up brachiating. The faster you can brachiate, the faster you get to the new food source (or get away from the scary thing chasing you!).

This acrobatic ability has made apes the top gymnasts in the world. And while humans tend to get all the attention for it (especially during the Olympics), sometimes it's good to remember that our cousins have this cool ability, too. I'll end this post with an awesome video of a gibbon showing off this super flexible shoulder joint to mess with a couple tigers. Someone get that ape a gold medal!