Let’s Talk About Sloths, Baby

Let’s Talk About Sloths, Baby

If you’re a fan of The Skeptics’ Guide to the Universe, you may want to avoid this post until you’ve heard the most recent episode, since I’m going to spoil that show’s Science or Fiction segment starting right about now.

Because we recorded three entire shows in one week before and during the Northeast Conference on Science and Skepticism, Steve wasn’t able to handle running all the Science or Fictions, which is the near-final segment of each show in which the panelists must pick the fake story out of three (or four) news items.

I filled in once before and was able to trick one or two of the guys, but this time I wanted to pitch a no-hitter. I asked the Skepchicks for help, and they suggested I choose a theme that I am very well-acquainted with: sloths.

(SPOILERS AHEAD!) I’m happy to say that not only did I stump all four of my SGU co-hosts, but I also fooled our guests, James Randi and Seth Shostak, plus all of the 20 or so people who were in the audience of the intimate live recording. Success! Here were the items I gave them:

1.) Recent phylogenetic analyses suggest an extremely recent common ancestor between two-toed sloths and three-toed sloths, which occupy the same territory, subsist on the same diet, and even have the same number of toes despite the name difference.

2.) Sloths move so slowly that a blue-green algae grows on them, living symbiotically in their hollow hair and providing sustenance for dozens of varieties of arthropods.

3.) Despite the fact that they are incapable of walking, sloths climb down from the trees, poop in a small hole at the foot of the tree, and then climb back up.

4.) Sloths are graceful swimmers who can perform a breast stroke and are descended from an aquatic sloth ancestor.

I’ll give you a second before I reveal the answer, in case you want to figure it out.

Okay, give up? The panelists, guests, and audience were all pretty evenly split between guessing that the fictional item was #3 or #4. However, the actual fiction is #1.

It’s true that 2-toed sloths and 3-toed sloths are incredibly similar, and it’s even true that they have the same number of toes, technically (“2-toed” sloths have two claws on each hand, as opposed to three). But despite this, their common ancestor lived 35-40 million years ago and 2-toed sloths are more closely related to an extinct type of ground sloth than to 3-toed sloths. The species are an example of convergent evolution, due to the similar evolutionary pressures placed on both of them.

Swimming sloths and sloths that poop on the ground were the most difficult for the panelists and audience to believe, but (hooray!) there’s plenty of video evidence to prove the point. Enjoy!

Sloths pooping on the ground (they only poop once a week, and boy do they love it):

Check out how green this mother is:

(Pygmy!) sloths swimming:

This sloth is clearly like, “please get out of my face. You are not saving me.”

As always, more sloth pics can be found on my Pinterest.

Avatar of Rebecca Watson
Rebecca leads a team of skeptical female activists at Skepchick.org and appears on the weekly Skeptics' Guide to the Universe podcast. She travels around the world delivering entertaining talks on science, atheism, feminism, and skepticism. There is currently an asteroid orbiting the sun with her name on it. You can follow her every fascinating move on Twitter or on Google+.

11 Comments

  1. Avatar of Will

    Excellent! =)

  2. Avatar of Skunk_Ape

    OK, the baby sloth wearing a little white sweatshirt is just about the cutest thing ever.

    But what’s up with the one at the top of this page sporting the Bieber hair do??

  3. Avatar of Tobasco da Gama

    I’m disappointed that you didn’t make good on your promise/threat to do a My Little Pony-themed S-or-F.

  4. Avatar of criticaldragon1177

    Rebecca Watson

    That picture you choose for the article looks kind of like a stuffed animal, it also reminds me of Chewbaca from original Star Wars trilogy.

  5. Avatar of ineedavacation

    “2.) Sloths move so slowly that a blue-green algae grows on them, living symbiotically in their hollow hair and providing sustenance for dozens of varieties of arthropods”

    I think I’m probably the only one to interpret this to mean that sloths must smell REALLY bad.

  6. Avatar of Cloe

    I totally would have aced that science or fiction! I once did a webcomic about sloths and their ancestory.
    Also, one anagram of my name is Ocean Sloth.

    http://th03.deviantart.net/fs70/PRE/f/2011/142/2/b/sloths_by_obviouslycloe-d3h04xu.jpg

  7. Avatar of Chris Bowers

    “It’s true that 2-toed sloths and 3-toed sloths are incredibly similar, and it’s even true that they have the same number of toes, technically (“2-toed” sloths have two claws on each hand, as opposed to three). ”

    In other words, the misnomer is a confusion between fingers and toes, which I have always found really odd.

  8. Avatar of Jason J Brunet

    I’ve looked, but I haven’t been able to find evidence that modern sloths descended from aquatic sloths. Yes, I know they existed, but that doesn’t mean they gave rise to modern sloths.

    In fact, #1 contradicts #4. The oldest aquatic sloths are from the late Miocene, maybe 10mya to 5mya, but modern two and three toed sloths diverged 35mya.

  9. Avatar of Bjornar

    A bit of cross plattform discussion here, but the aquatic slot you link to in reply to this tweet:

    @Three_Ninjas: “[Sloths] are descended from an aquatic sloth ancestor.” …Where’s the evidence for this?

    is in a different Family, Megatheriidae, than modern sloths, which are in Bradypodidae and Megalonychidae. Further, the Megatheriidae family is full of plain old non-aquatic ground slots. The aquatic one appears to be the odd sloth out, rather than an important stage in sloth evolution.

    http://en.wikipedia.org/wiki/Sloth#Evolution

    Of course, my motivation for looking into this, despite my complete lack of expertise in sloth evolution, has nothing to do with me answering 1: F, 2: S, 3: S, 4: F and wanting to be right.

  10. Avatar of Ken Keenan

    One theory I’ve heard for why sloths risk pooping on the ground is that it is one of the few opportunities for these otherwise-solitary animals to hook up. Which must make sloth dates real fun:

    Male Sloth: Uhm, do you come here often?
    Female Sloth: Oh, now and then. [poops]
    Male Sloth: Say, I love what you’ve done with your hair! Is that algae?

  11. Avatar of jengajam1

    I’m very happy to say that I would have got this right, a rare occurence.

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