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  • Good morning, John! My name is Dr. Lawrence Turtleman.

  • Hank graciously handed the reins over to me for the last day of Pizzamas,

  • which is a huge honor. I really loved watching Pizzamas over the last couple of weeks.

  • The haul videos, the reunions, the almond orchards, the reviews, but me, Dr. Turtleman, I'm here to talk to you today about

  • taxonomical oddities. See, all organisms on Earth are related to each other. We can

  • trace that the way that scientists did for hundreds of years using the morphology of organisms, and we can

  • also trace it using genetics. Like it's easy to see how

  • a tiger and a lion are related to each other, and it's easy to see how a wolf and a fox would

  • be related to each other. But you can also kind of tell that

  • a lion and a wolf are more related to each other than they would be to, say, I don't know,

  • like a sheep or a turtle man. And if we look into the fossil record, we can

  • find the common ancestor of dogs and cats: it's the miacid, a sort of weird proto-carnivore bear-dog-cat thing. Now when

  • we learned about organisms and their relationship to each other in school, we learned

  • about it through the lens of

  • taxonomy. Every category in taxonomy, going all the way from domain

  • down to species, is called a taxon. And every taxon is built to contain multiple taxa. So in the order carnivora

  • we have all kinds of families: We have the canids and the felids,

  • we also have the ursids and the pinnipeds and the mustelids,

  • and each of those families there are multiple genera, and in each of those genuses there are a bunch of different species. But in these

  • weird taxonomical islands that I want to talk to you

  • about today, you might find yourself with an order that only has one

  • family in it that only has one genus in it that only has one species in it. That'd be like having only one

  • carnivore currently existing on the planet! Is this a thing that could even happen?! As far as I can

  • tell, this is only the case for two terrestrial vertebrates; we have:

  • order tubelidentata containing just the one species, the aardvark

  • aardvarks are extremely successful and roam all across Africa but nevertheless, all of their ancestors have

  • gone extinct.—and we have order opisthocomiformes,

  • which contains just the one species, the hoatzin. The hoatzin is a South American bird that's really weird, which you can tell, by looking at it.

  • Look, look at that thing. But I do also want to talk about two runners-up here: a non-terrestrial vertebrate

  • that has two species in its order, the coelacanthiformes. We once thought that the coelacanths had been extinct for sixty-six million years,

  • until we found one in 1938, and then we later found another species. And finally, we also have order rhynchocephalia,

  • which contains the two species of tuatara.

  • Now we very nearly lived in a world with only one species of tuatara, but a second species

  • was found, living on only one island off the coast of New Zealand. Tuatara, of course, do look a lot

  • like modern lizards, but in fact, their last shared ancestor with the modern lizards and snakes was over a hundred

  • and fifty million years ago. And you might be asking, "Hey, Dr. Turtleman,

  • if they're so different from lizards and snakes, give me an example of one of those differences."

  • Well, tuatara like to bite and chew on stuff, but instead of using teeth to do that, they just grow

  • their bones up through their gums!

  • Now you might think that I'm done here that I've told you all of the weirdest taxonomic

  • islands. But the species that really takes the cake here is not an animal alone in its order! It's a plant,

  • alone in its division. The ginkgo tree shares a kingdom,

  • which is the second largest of all of the taxa, with all

  • plants, and then after thatit is all on its own, the only species

  • in its division. And remarkably, now

  • that you humans have come to enjoy them so much, they've been planted all over

  • the world and spread out from their original location in Asia. The ginkgo trees have been welcomed into the

  • Anthropocene, a lovely species stretching back through time, alone on one of the most isolated of taxonomic islands.

  • Hank: Ah. Thank you Dr. Turtleman, that was, that was a lovely

  • presentation.

  • Turtleman: You're very welcome, Hank! It was a, it was a true honor.

  • Hank: You're great. And thank you to everyone for hanging out this Pizzamas.

  • It's been a great time. I can't believe that it's already over. Now is also your last time if you

  • want to get this year's Pizzamas stuff. We make it for two weeks and then never again, so if you go to dftba.com/pizzamas

  • or click on the end screen here, you can get some of that stuff. Thanks for joining us this Pizzamas,

  • it's been a really good time, and John I will see youlike normalon Tuesday.

Good morning, John! My name is Dr. Lawrence Turtleman.

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B1 hank dr carnivore related terrestrial ancestor

The Weirdest Living Animals - (With Dr. Lawrence Turtleman)

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    林宜悉 posted on 2020/04/13
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