No More Monkey Business

Apes and Monkeys

Except that’s not true either.

Humans are not monkeys.  Humans are apes.  Apes are not monkeys.  Look, it gets complicated.

Let’s start at the top, shall we?  Humans are primates; and on this point just about everybody agrees (neglecting Creationist arguments that humans are somehow distinct from all animal orders and are a clade unto ourselves).  Primates are divided into two sub-lineages:

  1. strepsirrhines, which include lemurs, lorises, bush babies, and pottos.  The streppies (an unofficial name which I have just now coined for them) are characterized by their wet noses and by their ridiculously adorable large eyes.
  2. haplorhines, which include tarsiers and simians.  Happies have dry noses (except during pollen season, am I right?) and the all-important ability to make comical facial expressions.  I’m totally serious about that: haplorhines have a lip adaptation that enables them to contort their faces into all sorts of goofy shapes that are, sadly, beyond the reach of strepsirrhines.

Humans are haplorhines and simians.  Imagine what Jim Carrey’s career would have been like if humans were streppies.  Anyway, as is often the case in the biological classification game, each hierarchy has hierarchies above and below.  Simians are divided into even more specific groups:

  1. The flat-nosed, or New World monkeys (from Central and South America), which include: marmosets; tamarins; capuchins and squirrel monkeys; night or owl monkeys; titis (snicker); sakis and uakaris; and howler, spider and woolly monkeys.  As the name implies, New World monkeys are all part of the nefarious New World Order, which, with the help of the Illuminati, are poised to take over control of the entire world.
  2. The down-nosed simians, which include Old World Monkeys (from Africa and Asia) and the apes.

Now let’s pause for a moment and reflect on what we’ve learned.  Humans, apes, and monkeys all share a relatively recent (by geological standards) common ancestor, and we’re all part of the same order.  But let’s wave goodbye to the monkeys, for it is at this point that humans and our ape brethren take an evolutionary detour.  Once we start down the path of apeness, ne’er another monkey shall we see.  So what is it that distinguishes apes from monkeys, structurally speaking?

As this page explains, apes tend to be larger than monkeys (although there is a slight overlap in general body sizes).  Apes also lack tails, have a broader chest than monkeys, and are often able to walk upright (and in the case of humans, do so almost exclusively).  The apes belong to a superfamily called Homonoidea, and (surprise!) this group may be further divided into smaller groups.

  1. The lesser apes – a hurtful epithet if I’ve ever heard one – include the gibbons of India, China, and Indonesia.
  2. The great apes: chimpanzees, orangutans, gorillas, bonobos, and yes – humans.  Great apes are generally larger than all other primates, have a more upright posture, exhibit some degree of sexual dimorphism (meaning males and females differ markedly in appearance), and have nimble fingers that can be used to make and wield tools.

So here we are, at the tail end of a hierarchy of hierarchies (as are all other extant species; I didn’t mean to imply that humans occupy a position of evolutionary superiority).  Humans are apes, and apes are not monkeys.  Apes and monkeys are related, but the relationship is more like that of very distant cousins.  The meme’s second line should properly read “Think of yourself as a beautiful ape.”

Because you know what?  You are a beautiful ape.  You really are.


Pluto Pique

Pluto Not A Planet

Pluto And Your Mom


Okay, so the second meme is kind of funny in that it appeals to my inner teenager. It’s still Stupid (as are most things that appeal to my inner teenager).

I’m pretty sure that none of these pictures actually depicts Pluto. The first one is definitely Ganymede, the largest moon of Jupiter, although the color appears to have been tweaked a little. The last image depicts…well, I’m not sure. But it isn’t Pluto.

Here are the best images we have of Pluto until the New Horizons probe flies past it in 2015.

Pluto Images Hubble

Look, I understand the Pluto grief, especially in the United States. Pluto was the only Solar System planet discovered by an American, so its demotion in 2006 by the International Astronomical Union (IAU) must have seemed like a blow to American pride. Besides, kids around the world grew up learning about the nine planets. Sure, Pluto was a bit of an oddball with its eccentric, highly-tilted orbit, but that’s what made it cool. Pluto was kind of like that quiet kid who never really got to know anybody, but he could make those awesome paper airplanes that would fly for miles. Yeah…Pluto was like that kid.

So yes, I get why people were upset…angry…maybe a little betrayed…by the sudden switch. Except it wasn’t so sudden. The motivation that eventually led to Pluto’s demotion had been brewing for years. Astronomers started to find other ice-rocks similar to Pluto orbiting the Sun far, far out in the frigid realm of the Kuiper Belt. Some of these objects were as large as Pluto, if not larger. It was becoming increasingly difficult to defend calling Pluto a planet if you weren’t going to afford planetary status to all those other rockcicles.

I imagine that astronomers were getting uncomfortable attending parties with all the irate parents demanding to know if their kids were going to have to memorize ten – excuse me, twelve – scratch that, thirteen planets. I envision a lot of awkward throat clearing and desperate attempts to change the subject.

It didn’t help that there wasn’t even a formal definition of the word planet. Much like Supreme Court Justice Potter Stewart, who knew obscenity when he saw it, some astronomers felt that they knew a planet when they saw it. Unfortunately this highly subjective means of identifying planets wasn’t exactly rigorous. It was time to make a decision.

That’s exactly what the IAU did during their conference in Prague in 2006. At long last, after years of debate, an official definition existed for the word planet.

The definition, which did almost nothing to quell the controversy, has three criteria. In order to be considered a planet, an object must:

  1. Orbit the Sun. Pluto passes this test, but so do all the other objects that were making things difficult to start with, so no help there.
  2. Be large enough to pull itself into a sphere by its own gravity. Remarkably, Pluto also passes this test. That means that Pluto’s demotion has absolutely nothing to do with its size! Do you hear that, funny-but-stupid meme in the middle?
  3. Clear its orbital neighborhood of debris. And here is where Pluto loses out – along with all the other bodies whose planetary status hinged on this very decision. Pluto orbits the Sun in a region called the Kuiper Belt, which is occupied by zillions…no, gigajillions of other bodies. The combined mass of these bodies is greater than the mass of Pluto itself, so you can’t really say that Pluto has cleared it’s neighborhood. In fact, Pluto starts to look a bit like a hoarder.

Now I don’t really have a problem if you’re disappointed in Pluto’s demotion. (Although come on, man…it’s been seven years. Time to move on.) I do have an issue with people who don’t understand the scientific reasoning that went into the decision. Just so we’re all clear:

  • It’s not the size that counts, as long as a planet is large enough to be round. Pluto’s got the mass to pull it off.
  • There are lots of objects besides planets that orbit the Sun. Yes, planets consume the vast majority of the non-Sun mass in the Solar System, but when you consider numbers alone, they are a tiny minority. Pluto is in good company.
  • The IAU’s definition of planet says nothing about moons. If it did, then Mercury and Venus would be excluded from planetary status.

For my part, I like Pluto. I can’t wait to see the detailed photos that return from the New Horizons probe when it zips past the Pluto system. But I’m not going to worry too much about what we call the object in the pictures. You shouldn’t either.