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How Fossils Work · Stuff You Should Know

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Speaker 1: Brought to you by the reinvented two thousand twelve camera.
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Speaker 1: It's ready. Are you welcome to stuff you should know
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Speaker 1: from house Stuff Works dot com. Hey, and welcome to
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Speaker 1: the podcast. I'm Josh Clark with me as always as
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Speaker 1: the intrepid paleontologist Charles W. Chuck Bryant. It's terrible, Wasn't
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Speaker 1: I like it? Okay? I wish I was a Paleontologist's
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Speaker 1: your new nickname? Or intrepid? At least? Let's just go
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Speaker 1: with paleontologists. That'd be great. Okay, we're talking fossils today. Dude,
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Speaker 1: this isn't really interesting stuff? It really is. And um,
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Speaker 1: you can tell that Tracy Wilson are esteemed head of
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Speaker 1: the writing editor. I think she's site director director right. Um,
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Speaker 1: you can tell that she was very, very excited. She
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Speaker 1: took her time and really dolled this one out. I think, um,
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Speaker 1: save her is the right word. You can feel it
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Speaker 1: her smiling through the keyboard. Yeah, she's very happy to
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Speaker 1: write how fossils work, and um, we're happy to do
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Speaker 1: it because it's one of those very comprehensive articles on
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Speaker 1: the site that you just has. It has everything you need.
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Speaker 1: Sedimentary rock flat bones versus round bones leaf impressions has
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Speaker 1: it all unless you're an intrepid paleontologist, and we'll get
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Speaker 1: an email saying it actually wasn't very comprehensive. You guys
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Speaker 1: royally screwed this up. We just wait until we get
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Speaker 1: into punctuated versus gradual evolution. Chuck, Um, you've heard of
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Speaker 1: Lucy right, the austral epithecuss Yeah, okay, Well, Um, she
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Speaker 1: was I think three point two million years old. That's
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Speaker 1: one old lady. It really is the earliest hominid we've
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Speaker 1: found as far as I know. Um, But there's a
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Speaker 1: part of her foot missing. It's always been missing that
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Speaker 1: we've never found before. So this thing, this bone, was
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Speaker 1: so essential that we couldn't tell how she walked until recently.
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Speaker 1: Why because the missing bone, we couldn't tell how she
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Speaker 1: walked exactly. We we we can tell so much from
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Speaker 1: bones that when we don't have the right bones, we
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Speaker 1: can't tell anything. So she may have been in a
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Speaker 1: knuckle dragger, she may have hopped, we didn't know. Well. Recently, Um,
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Speaker 1: some people from the University of Missouri or Missouri, depending
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Speaker 1: on whether or not you live in the state, UM
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Speaker 1: found the Uh, the group of foot bones needed to
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Speaker 1: show what kind of walker Lucy was. And she walked
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Speaker 1: up right? How was her gate? Upright? Upright? Just like
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Speaker 1: a human. She had a hitching her get along, she
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Speaker 1: had a pepper and her step. Possibly she knew she'd
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Speaker 1: be famous one day with duck. But but consider this, right,
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Speaker 1: three point two million year old footbones were found and
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Speaker 1: we could tell from them how she walked. This is
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Speaker 1: the state of the field that you remember paleontology. Pretty cool.
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Speaker 1: This is how advanced it is, and yet it's really
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Speaker 1: just kind of using common sense to figure out what
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Speaker 1: old bones mean. Common sense and science. Fossils go, let's
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Speaker 1: talk about it, Chuck. What are some of the different
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Speaker 1: kinds of fossils. Uh, well, one of my favorite kinds
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Speaker 1: is trace fossil. Yeah, that's actually one of my favorites too.
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Speaker 1: It's like, um, that Jesus footprint thing, footprints in the sand. Yeah,
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Speaker 1: it's sort of this josh um that is when it's
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Speaker 1: actually not part of the organism at all, but it's
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Speaker 1: um like tooth marks in a chunk of wood from
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Speaker 1: a saborite tooth tiger, or footprints or footprints or track ways,
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Speaker 1: as Tracy calls them. Yes, footprints, it's just unnecessary, but
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Speaker 1: it has a pleasant tone, you know science. Yeah, they're
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Speaker 1: not footprints, the track ways I'm bored in Ethiopia, let's
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Speaker 1: call so trace fossils is one. Of course, there's bone fossils, right,
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Speaker 1: the most famous fossils. Yeah, those are great too. They
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Speaker 1: got nothing on trace fossils. So actually, bone fossils, that's
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Speaker 1: that's what you really want. If you're going to reconstruct
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Speaker 1: a dinosaur for your museum. You can't deal it with footprints, No,
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Speaker 1: you can't. You need the bones. And the bones are
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Speaker 1: of course the most famous ones in the dinosaur bones
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Speaker 1: are the most famous of all the bone types. Right.
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Speaker 1: So there's something that I think um is often missed
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Speaker 1: by lay people such as myself um in in that
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Speaker 1: when you find a bone, right, so, you find like
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Speaker 1: a big old dinosaur bone, it's really geologically speaking, it's
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Speaker 1: not a bone any longer. It's not like you find
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Speaker 1: a bone buried in your yard that was an animal
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Speaker 1: from like, you know, thirty five years ago, but that's
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Speaker 1: not a fossil. That's still bone. A fossil is a
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Speaker 1: bone or a piece of um, once living organic material
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Speaker 1: that's undergone a transition from uh, an organic state to
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Speaker 1: an inorganic state. That's what a fossil is. It's gone
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Speaker 1: through the process of fossilization. And most of these fossils,
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Speaker 1: the vast majority of fossils, are found in sedimentary rock.
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Speaker 1: Before we go any further, we should probably do a
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Speaker 1: little brief primer on sedimentary rock, right, which is awesome. Yeah,
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Speaker 1: it's pretty easy to Uh, we've talked about the Earth's core,
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Speaker 1: um and layers. When I think we talked about earthquakes
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Speaker 1: and maybe some other stuff. We all know that there's
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Speaker 1: the inn core, outer core. We got the crust. Crust
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Speaker 1: is the thinnest layer, and that's where the fossils are.
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Speaker 1: That's where the goods are. And uh, most of the
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Speaker 1: rocks in the crust are sedimentary rocks. You've been talking
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Speaker 1: about off and on for the past eight minutes, right,
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Speaker 1: And that's like silty sandy stuff that hardened over the right,
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Speaker 1: I mean, but the the Earth, Remember we talked about oh,
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Speaker 1: what was it clouds I can't remember what podcast it was,
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Speaker 1: but we talked about how much sand is transferred from
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Speaker 1: Africa to South America annually. But if you remember the
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Speaker 1: one I'm talking about. Okay, so the Earth's geo biogeochemical
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Speaker 1: processes equal a lot of movement of particulate matter. Right.
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Speaker 1: The Earth is dynamic, baby, it is. It's also very fluid.
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Speaker 1: To write, A lot of that matter is at at
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Speaker 1: one point as suspended particles in water that's moving around, right.
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Speaker 1: So um as this as the water leaves and the
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Speaker 1: sediment is deposited, it builds up and up and up.
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Speaker 1: Over time, it hardens into rock and eventually we have
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Speaker 1: sedimentary rock which is below our feet. We don't normally
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Speaker 1: see it unless say, the Colorado River um winds over
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Speaker 1: it for you know, millions and millions and millions of years,
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Speaker 1: revealing the sedimentary rocket that's in the Earth's cross Grand Canyon,
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Speaker 1: exactly what you're talking about. Yeah, I forgot the Grand
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Speaker 1: Canyon park. So you know how I said the Earth
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Speaker 1: was dynamic, baby? Yeah? Uh, that's important. I didn't just
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Speaker 1: throw that in there as a factoid. It's important because
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Speaker 1: when these plates shift around, that's how fossils are on Earth.
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Speaker 1: Things can be moved great distances and pushed to the
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Speaker 1: surface eventually or close enough to where a dig can
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Speaker 1: unearth it. And it's like just because it's fossilized, doesn't
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Speaker 1: mean it's stuck in that one spot forever, because Earth
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Speaker 1: is always moving. So the point of all this is
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Speaker 1: is sedimentary rock um is like you said, dynamic. It
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Speaker 1: moves around. Sometimes fossils pop up, or it becomes exposed
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Speaker 1: all of the Colorado River um, and that is where
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Speaker 1: fossils are, right Chuck. Yes, So let's say that at
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Speaker 1: some point in time there was a dinosaur or a
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Speaker 1: saber tooth tiger or a cyanobacteria wily mammoth, woly mammoth,
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Speaker 1: sure um, and it's um hanging out around the riverbed
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Speaker 1: and it has a massive heart attack and falls over
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Speaker 1: in the river bed and very quickly it becomes covered
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Speaker 1: with sediment and silt, right yeah, And that's important because
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Speaker 1: once it starts getting covered up with stuff, it's sort
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Speaker 1: of being protected from like all of us. Let's just
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Speaker 1: break the news. All of fossil means is that something
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Speaker 1: has been protected from the natural decomposition process. Otherwise we
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Speaker 1: just decompose like everything else and you wouldn't see anymore.
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Speaker 1: You just totally betrayed Tracy in the tone she went
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Speaker 1: to this, that the whole drama drawing out suspense. But
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Speaker 1: that's true. So what you said was right. So you'd
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Speaker 1: fall over in a riverbed, you start getting covered up
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Speaker 1: with the sediment and silt, and it's it's immediately starting
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Speaker 1: to protect you in a way. Um, not you, but whatever,
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Speaker 1: the wily mammoth, the wooly mammoth. Um. The thing is
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Speaker 1: the in this sediment, in this still, you can't really
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Speaker 1: hide from macrobacteria, uh and other forms of life that
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Speaker 1: are basically dedicated to breaking down organic matter, soft tissue, hair, eyeballs, um, genitalia,
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Speaker 1: all that kind of stuff. It eventually becomes broken down
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Speaker 1: and what's left is the hard stuff, the bone, right,
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Speaker 1: But the bone also has organic material within it as well. Yeah,
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Speaker 1: and that'll break down. We're talking blood, cells, collagen, fat,
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Speaker 1: that's gonna break down. To the key here is the
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Speaker 1: inorganic parts of the bone remain intact. And it's the
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Speaker 1: other keyword here's porous. Yes. Well, you take calcium, I
9:41
Speaker 1: imagine for your hips. Yeah, sure, glucosim and calcium. Sure.
9:47
Speaker 1: So what you're doing is, um, you're fortifying the calcium
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Speaker 1: that's already in your hips supposedly, um, because the bone
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Speaker 1: is made in large part of calcium, which is a mineral,
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Speaker 1: which is inorganic, So it's all the organic stuff dies
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Speaker 1: that out. What's left is, like you said, the inorganic
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Speaker 1: like calcium, whatever, minerals, and that holds the shape, right. Yeah,
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Speaker 1: the initial structure is kept intact, right, But like you said,
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Speaker 1: this bone is also porous. Yeah, that's the key, and
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Speaker 1: over time, um other mineral sediment kind of um it
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Speaker 1: enters into these these microscopic pores iron right, carbonate and
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Speaker 1: fortifies this, ultimately turning this but what was once an
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Speaker 1: organic bone into an inorganic rock in the shape of
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Speaker 1: the bone. Yeah, but for all intensive prefaces, it's still
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Speaker 1: the bone. It still has that original calcium. It's still
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Speaker 1: the same thing. It's not like a replica of it.
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Speaker 1: It's just become fossilized. Yeah. And Tracy in the article
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Speaker 1: uses a pretty good example. I thought, it's like filling
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Speaker 1: a sponge with glue. The sponge is gonna keep the shape,
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Speaker 1: but the glue is gonna ouze through all these spots
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Speaker 1: that it can ouze harden, and there you go. You've
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Speaker 1: got a hard sponge, a hard sponge, which is basically
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Speaker 1: what a fossil is. And this takes place Josh over
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Speaker 1: the course of millions of years, the sediment reinforcing the
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Speaker 1: bones eventually becoming rock. It's not the kind of thing
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Speaker 1: that happens willy nilly over thousands of years a long time,
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Speaker 1: and it's just this isn't just UM happening by itself.
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Speaker 1: All of the surrounding area UM is being deposited with
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Speaker 1: sediment as well. It's also turning into rock UM. And
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Speaker 1: then the ultimate test of time for a fossil is
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Speaker 1: that it can withstand the pressure of the that's mounted
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Speaker 1: by the hardening rock sedimentary rock that's growing around it,
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Speaker 1: so it can be crushed. Is that how? A lot
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Speaker 1: of fossils are definitely crushed crushed the death um. But
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Speaker 1: if it survives and you can find this, you will
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Speaker 1: eventually be able to get to it. And then you
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Speaker 1: remove the rock from around the fossil, and there's your
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Speaker 1: bone that you can take to the Natural History Museum
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Speaker 1: and get at least five dollars for When you were
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Speaker 1: a kid, Josh, let me ask this, did you ever
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Speaker 1: go into the woods on a little nature course from
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Speaker 1: like a science center, let's say, and do a cast
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Speaker 1: plaster cast of a animal footprint? Do you ever do that? No? Really,
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Speaker 1: really I did that. We went and found like deer
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Speaker 1: hoof prints, you fill it with plaster, and there was
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Speaker 1: some way of doing it where you got an inverse
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Speaker 1: plaster cast of a deer hoof print. That can happen
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Speaker 1: actually in a way that with trace fossils, So you can,
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Speaker 1: you know, sediment connect the same way in one of these.
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Speaker 1: Let's say the wooly mammoth makes a footprint in some
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Speaker 1: loose but sturdy soil that fills up with sediment and
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Speaker 1: creates basically a mold, just like I did as a
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Speaker 1: kid with the plaster cast. Yeah, as long as the
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Speaker 1: sediment that fills it in is lighter or thinner, yeah
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Speaker 1: than the soil that the impression is made in, then yeah,
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Speaker 1: it would it would, It would preserve that track. Yeah,
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Speaker 1: And plants can do the same thing. It's not just
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Speaker 1: bones we're talking about. Um. It can also fill in
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Speaker 1: in a different way. I guess the was it way
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Speaker 1: to where it makes a basically a cast of the
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Speaker 1: foot that made the track. And then so it's like
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Speaker 1: a kind of like a fossil of a ghost foot
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Speaker 1: that's not really there, but it makes the foot. It's
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Speaker 1: like an inverse cast, okay, of not the track, but
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Speaker 1: the foot that made the track cool. You know what.
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Speaker 1: Other another my favorite trace fossil is it's not a
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Speaker 1: track way, it's copper light. I changed my mind. That
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Speaker 1: is a good one. That's done it poop, fossilized poop,
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Speaker 1: that's right. I can tell you a lot about an animal.
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Speaker 1: It can tell you about its fiber intake. It can
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Speaker 1: tell you about what size it's poop was. Um chuck.
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Speaker 1: You know, in the eighties the CIA found out much
13:48
Speaker 1: about Gorbichoff and his health. They found out he had
13:51
Speaker 1: like cancer or some sort of chronic illness um by
13:56
Speaker 1: stealing his poop when he was when he came the
14:00
Speaker 1: state visit to the US, they took his poop and
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Speaker 1: analyzed it, and when he was in the US they
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Speaker 1: described it from the toilet. Did he not flush? I
14:10
Speaker 1: just want more specifics that you probably don't have. As
14:12
Speaker 1: far as I understand, they probably his hotel room or
14:15
Speaker 1: wherever he was staying. They were prepared to do this.
14:19
Speaker 1: This was like toilet rigged. Probably yes, But wherever Reagan
14:23
Speaker 1: went they had a portable toilet that he used. It
14:26
Speaker 1: was the only one he was allowed to use. I'm
14:27
Speaker 1: not kidding. So no one can steal his poop. Talk
14:31
Speaker 1: about paranoid. Yeah, seriously, when you point one finger, there's
14:36
Speaker 1: three pointing back at you, you know what I mean. Yeah? Yeah,
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Speaker 1: Uh so, Josh, that is sedimentary rock and that's to
14:43
Speaker 1: me one of the cooler ways you can get a fossil.
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Speaker 1: Petrified wood too. Don't leave that one out. It's basically
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Speaker 1: the same thing that we just described for bone, but
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Speaker 1: for wood hard as a rock because it is a rock.
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Speaker 1: Here you go, alright, So like I just said, um,
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Speaker 1: that was dementary rock and that's kind of fun. But
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Speaker 1: you can also uh get a fossil. Has that funny
15:06
Speaker 1: because one dies in a cave that's really dry. Yeah.
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Speaker 1: Desiccation Yeah, desiccation is basically, uh, sort of a mummification,
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Speaker 1: but it's not like we think of with mummification with
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Speaker 1: the Egyptian tombs or anything like that. Well, that's because
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Speaker 1: there's no preservation techniques that have been undertaken. Basically, it
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Speaker 1: dries out. It's like throwing an orange in a dehydrator.
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Speaker 1: So when it's really dry, there's not gonna be any
15:30
Speaker 1: place for bacteria to thrive. That's the reason beef jerky
15:33
Speaker 1: is not um refrigerated. If you refrigerate your beef jerkey,
15:36
Speaker 1: you're you're doing something wrong. Yeah, that's true. Well, if
15:40
Speaker 1: you have beef jerky long enough to need refrigeration, then
15:43
Speaker 1: you're doing something wrong or something really really right. Uh
15:48
Speaker 1: So desiccation actually works so well sometimes that it can
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Speaker 1: preserve the skin and soft tissues as well, which is
15:55
Speaker 1: something that sedimentary rock cannot do. Have you been to
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Speaker 1: the Smithsonian? I have they have um a very cool
16:01
Speaker 1: I guess a prehistoric cow or a musk ox I
16:04
Speaker 1: can't remember, but it's the thing's head, um, much of
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Speaker 1: its back, I guess, the cape, two of its legs,
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Speaker 1: and the skin is still there. It's just right there.
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Speaker 1: Probably it's tens of thousands of years old and it's
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Speaker 1: just sitting right there. Did they rebuild could they rebuild
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Speaker 1: it or just put the parts up? It's just the parts,
16:23
Speaker 1: but it's laid out so that like it gives you
16:26
Speaker 1: the impression of what you're looking at, but its face
16:28
Speaker 1: is still there. It's very cool. Uh. My favorite kind
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Speaker 1: of fossil, though, Josh, is I'm gonna say that, like
16:34
Speaker 1: every five minutes is a frozen fossil. Because if you
16:39
Speaker 1: get trapped let's see your wily mammoth trapped in ice.
16:42
Speaker 1: Not only is that going to keep other like vultures
16:44
Speaker 1: and things from picking up your bones and skin, but
16:47
Speaker 1: it's also going to keep it from breaking down. And
16:50
Speaker 1: you can get hair fully preserved sometimes if you're in
16:55
Speaker 1: skin and like a big mammoth. Have you seen pictures
16:57
Speaker 1: of Leuba No? Liuba is a baby wooly mammoth that
17:01
Speaker 1: was found um by a reindeer herder in Siberia and
17:05
Speaker 1: um it was pounds or something like that, but it
17:08
Speaker 1: would have gotten up to several times. It is adorable
17:11
Speaker 1: because it is a fully preserved wooly mammoth baby with
17:16
Speaker 1: the wrinkles in the skin and everything, yet spent forty
17:19
Speaker 1: years in the perma frost. But it's like completely intact.
17:23
Speaker 1: It's very cute. That's why it's my favorite. It's one
17:26
Speaker 1: of the cutest dead things you'll ever see. Another couple
17:30
Speaker 1: of ways you can get a fossil josh, which are
17:33
Speaker 1: not my favorite, are a tar librea tar pits, although
17:37
Speaker 1: that is one of my favorites, which librea tar pit
17:40
Speaker 1: is actually redundant because Librea means the tar, so it's
17:43
Speaker 1: calling it the tar tart pit, and not the tartar.
17:46
Speaker 1: Did I ever tell you about when I shot a
17:48
Speaker 1: commercial there? Have you? Did you go by there in
17:51
Speaker 1: l A? No? I want to. I forgot about it
17:53
Speaker 1: when we were there last Well, for those of you
17:55
Speaker 1: haven't been, it's right in the middle of Los Angeles,
17:58
Speaker 1: like south of Hollywood on Wilson Bull Levard, and it's um.
18:01
Speaker 1: The main tar pit is uh. Tar pits are fenced off, obviously,
18:07
Speaker 1: and they have little recreations. It's it's actually the saddest
18:09
Speaker 1: thing you'll ever see. The recreation they have in there
18:11
Speaker 1: is of a like I guess it's a mother wooly
18:14
Speaker 1: mammoth trapped in the tar trying to get out, and
18:17
Speaker 1: the father and the baby on shore like howling. It's awful.
18:22
Speaker 1: But it's still active, like all this tars bubbling up
18:24
Speaker 1: and everything. And shot a commercial there once and I
18:27
Speaker 1: was on the other side of the property, far away
18:30
Speaker 1: from the main pit, and I looked down and there
18:34
Speaker 1: was a little mini tar pit, a little tar puddle
18:37
Speaker 1: about a foot wide, bubbling right beneath my feet. I
18:41
Speaker 1: could have scooped it up with my finger if I
18:43
Speaker 1: had been so inclined. Yeah, Instead, you're like that stinks. Well,
18:47
Speaker 1: it's just crazy to think that that's still like it's happening. Apparently,
18:51
Speaker 1: um I looked it up. There's um there's like you said,
18:54
Speaker 1: main pits that are chained off and that are still
18:57
Speaker 1: being excavated. But they have them like in neighborhood. It's
19:00
Speaker 1: all around the area and parks. They're just kind of
19:03
Speaker 1: all over the place around there. That's like parts of
19:05
Speaker 1: Stone Mountain popping up all over the place. We used
19:10
Speaker 1: We had a big chunk of stone Mountain in our
19:11
Speaker 1: backyard growing up. All right. For those of you don't know,
19:14
Speaker 1: Stone Mountain is the world's largest exposed piece of granite
19:17
Speaker 1: and it is right here in our home state. And
19:20
Speaker 1: it takes like thirty minutes to hike, but you still
19:22
Speaker 1: get to get to the top and be like I
19:23
Speaker 1: just hiked a mountain, which I have, Josh. You can
19:27
Speaker 1: also get a pete. Mossy pete can preserve life forms,
19:31
Speaker 1: including human beings like tolon Man? Was it? Who was
19:35
Speaker 1: that Toland Man? I don't know about him? How do
19:37
Speaker 1: you know? All these people? To people? The first the
19:40
Speaker 1: first um multi syllable word I could spell with archaeology. Really,
19:45
Speaker 1: I've always been interested in that I could see that. Yeah,
19:48
Speaker 1: Tolan Man. Also it doesn't. You can hate archaeology like
19:52
Speaker 1: some people hate art, and you'll still be interested in
19:55
Speaker 1: Toland Man. Um, he was He's found in Denmark. He
19:58
Speaker 1: lived years go and he was murdered. Uh, sacrificially they think,
20:04
Speaker 1: and cast into the peat bog which pete is just
20:06
Speaker 1: decomposing moss and lots of it, but it has a tendency.
20:10
Speaker 1: I think it's anaerobic. So um tissue is preserved really well.
20:14
Speaker 1: But it's this guy that they dug up and he's
20:16
Speaker 1: so well preserved that when they found him in the
20:18
Speaker 1: nineteen fifties they called the cops because they thought they'd
20:20
Speaker 1: found a murder victim, like a recent one. It looks
20:23
Speaker 1: kind of funny, but he's got his whiskers are preserved,
20:26
Speaker 1: he's wearing a cap, he still has this the garrett
20:29
Speaker 1: around his neck. Um, it's really awesome. So like three
20:34
Speaker 1: hundred to four hundred BC is one who was killed
20:37
Speaker 1: and he's wearing a hat. Yeah, sheepskin leather cap. Yeah.
20:42
Speaker 1: No last chance garage for him. No. Well uh. And
20:45
Speaker 1: then my favorite way, Josh, that you can get a
20:47
Speaker 1: fossil h you're joking. Did you say it again? Is amber?
20:53
Speaker 1: They just keep getting better and better, like the movie
20:55
Speaker 1: Jurassic Park. Yeah, that's how we get dinosaurs again. Yeah,
20:58
Speaker 1: dino d NA. So you found something on on whether
21:02
Speaker 1: or not that's feasible, right, Yeah, because I always wondered.
21:05
Speaker 1: You know, when you see Jurassic Park, you see the
21:07
Speaker 1: little video They made it clearly to explain to the
21:10
Speaker 1: movie going audience how this was done. It's better than
21:12
Speaker 1: Ellen Page running around. What was that movie inception? Um So,
21:19
Speaker 1: the mosquito flies and tree resident tree resident eventually becomes
21:22
Speaker 1: hard as copal than it eventually becomes inert as amber.
21:27
Speaker 1: You get the little mosquito in there. They extracted the
21:29
Speaker 1: dino DNA from the blood of the mosquito, filled in
21:32
Speaker 1: the gaps with I think frog DNA, and that was
21:36
Speaker 1: all there was to it. And at the time I thought, yeah,
21:40
Speaker 1: at the time, I thought that seems plausible, and it
21:42
Speaker 1: sort of is. But I did look up today and
21:44
Speaker 1: there was a researcher that was interviewed at the or
21:48
Speaker 1: closer to that time. I think that basically debunked it
21:50
Speaker 1: and said we could potentially maybe get some DNA even
21:54
Speaker 1: though it's really fragile and loses his signature really quickly.
21:58
Speaker 1: Even if you could get the in a he said
22:01
Speaker 1: that you couldn't construct a dinosaurs just you can't fill
22:05
Speaker 1: in the blanks like that. There's way too many blanks.
22:07
Speaker 1: You have a giant frog, yeah, with little tiny arms
22:11
Speaker 1: forearms that Steven Spielberg made us believe when you saw
22:14
Speaker 1: those dinosaurs walk across that field. That guy can make
22:17
Speaker 1: me believe in anything, that aliens came to the American Southwest,
22:22
Speaker 1: that there was a World War two. That um home,
22:27
Speaker 1: yea good stuff. Uh, where are we here? Chuck it.
22:32
Speaker 1: We're kind of painting this picture where if like you
22:34
Speaker 1: just stick a shovel anywhere on the Earth, you're gonna
22:36
Speaker 1: yield like all sorts of bones and fossils. No, it's
22:40
Speaker 1: not um. First of all, a mere fraction that I
22:45
Speaker 1: don't think could possibly be calculated because we rely on
22:48
Speaker 1: the fossil record to show us what existed back when,
22:52
Speaker 1: and it's incomplete. Therefore we've entered to catch twenty two.
22:56
Speaker 1: But there's just a mere fraction of all of the
22:59
Speaker 1: species organisms that's ever lived that become fossilized UM Like. Basically,
23:05
Speaker 1: a perfect storm of chance has to occur for a
23:08
Speaker 1: fossil to be created. As we've seen, even when it
23:12
Speaker 1: is created, it can still be crushed into oblivion. Um.
23:16
Speaker 1: And so there are few and far between to begin with.
23:21
Speaker 1: What we have to figure out where to find them? Well,
23:24
Speaker 1: then you got to find that. That's the other problem,
23:26
Speaker 1: and the way we find it is by identifying rock
23:29
Speaker 1: that will likely have the type of fossil that we're
23:32
Speaker 1: looking for. Yeah, so if you want something that from
23:35
Speaker 1: that year. So if you know that this animal, yeah,
23:39
Speaker 1: if you if you know this this animal lived, you know,
23:41
Speaker 1: thirty million years ago, you're gonna go find rock that
23:43
Speaker 1: you know is thirty million years old and start poking
23:46
Speaker 1: around and you know, looking this sort of a very
23:50
Speaker 1: chance thing. And we know that, um, we know, like
23:54
Speaker 1: say a layer of rock or strata of rock is
23:57
Speaker 1: thirty million years old because of the technique we have
24:01
Speaker 1: called radiocarbon dating. Right, Yeah, you want to do this one? Well, sure,
24:07
Speaker 1: Carbon fourteen dating is what a lot of people toss
24:09
Speaker 1: around because that's probably the most well known, but that
24:12
Speaker 1: can only take you back sixty thousand years and we're
24:15
Speaker 1: talking millions and billions of years, so they need to
24:19
Speaker 1: uh study isotopes like potassium forty and uranian two thirty eight,
24:24
Speaker 1: because that goes back millions of years evidently. The half
24:26
Speaker 1: life yeah, and the half life is where an atom
24:30
Speaker 1: loses half of its life isotopes to decay. Yeah, okay,
24:35
Speaker 1: and these the this um radioactive decay takes place at
24:38
Speaker 1: a predictable rate depending on the atom, the type of atom. Right, Yeah,
24:43
Speaker 1: that's how I understand it. So if we find the
24:46
Speaker 1: type of atom missing x number of isotopes, we can say, well,
24:51
Speaker 1: this is roughly thirty million to thirty one million years
24:54
Speaker 1: old or thirty million to thirty million and three hundred
24:57
Speaker 1: years old. I'm not sure what window we can date
25:00
Speaker 1: it to, right, but I think it's enough so that,
25:03
Speaker 1: you know, we have a rough estimate of of you know,
25:06
Speaker 1: when this fossil lived in the sediment was buried around it. So, Josh,
25:10
Speaker 1: let's say that you're lucky enough and skilled enough as
25:15
Speaker 1: an intrepid paleontologist to come across your fossil. What do
25:20
Speaker 1: you do? Well, as I said, you dig it up
25:24
Speaker 1: and take it to the museum and sell it for
25:26
Speaker 1: five d SIMOLEA. Well, I don't know about that, but
25:30
Speaker 1: you should call a museum. Even if you think you
25:33
Speaker 1: know what you're doing, you're probably gonna need some help.
25:36
Speaker 1: If it's something major. I think you should probably go
25:38
Speaker 1: on the assumption that you don't know what you're doing
25:42
Speaker 1: unless you're a trained paleontologist. Um. Part of the problem
25:46
Speaker 1: is is we assume that these fossils, being rocks, are sturdy.
25:49
Speaker 1: That's not always the case, and so there's a lot
25:52
Speaker 1: of danger of damage um in a just an average
25:57
Speaker 1: joe trying to excavate him. Also, if you just pull
26:00
Speaker 1: a bone up and walk away with it, uh, it
26:03
Speaker 1: immediately loses context. Yeah, it's like removing a piece of
26:06
Speaker 1: evidence from a crimesy almost exactly. Can't do that, well,
26:10
Speaker 1: you're not supposed to. Uh. So you know, they have
26:13
Speaker 1: these huge cranes and uh, digging tools where they can
26:17
Speaker 1: remove huge slabs of earth, which is a really good
26:20
Speaker 1: way to do it. And sometimes if they're you know,
26:22
Speaker 1: if it's something that could be fragile, they will remove
26:25
Speaker 1: the entire slab, cast it in plaster and just go
26:28
Speaker 1: ahead and ship that thing off to a facility to
26:31
Speaker 1: handle it from there. And the cool thing is is
26:34
Speaker 1: even though rock has formed around this bone, Yeah, that's right,
26:38
Speaker 1: up right, all up on it, all up in it.
26:42
Speaker 1: If you um flake it away properly, if you flake
26:45
Speaker 1: the surrounding sedimentary rock away, um, you're going to find
26:48
Speaker 1: that there's what's called the plane of weakness, which is
26:51
Speaker 1: where the bone and the rock are still on this
26:55
Speaker 1: very microscopic level, they're not fused together. You're gonna hit
26:58
Speaker 1: that and the box should chip right away and and
27:02
Speaker 1: leave the bone. Yeah, And I think sometimes they missed
27:04
Speaker 1: it with water too, to soften it up and help
27:07
Speaker 1: the whole process. Another thing too, if they find that
27:09
Speaker 1: is really brittle, they can actually reinforce the bone with
27:13
Speaker 1: resin and thin glue. But you need to be careful
27:16
Speaker 1: there too, which is pretty much helping along the fossilization process. Yeah,
27:22
Speaker 1: I would think so. I mean it's the same thing.
27:23
Speaker 1: It's like artifice, forcing it with something sturdy. Well, and
27:27
Speaker 1: then you can date it using your little mass spectrometer
27:30
Speaker 1: that's in your pocket and or a cat scan. Sometimes
27:33
Speaker 1: the use cat scans computer imaging stuff like that. Yeah.
27:37
Speaker 1: I didn't I didn't get how they were dating it
27:39
Speaker 1: from cat scan. I don't know if they're dating it
27:43
Speaker 1: with a cat scan or just sussen. The whole thing out. Gotcha.
27:46
Speaker 1: I don't think it's a dating situation. Tracy was just
27:49
Speaker 1: throwing out some extra tools of the trade. Huh yeah, exactly,
27:52
Speaker 1: gotch So um, chuck, what is all this worth? I mean,
27:57
Speaker 1: we we have a thirst for knowledge. Obviously people think
28:01
Speaker 1: bones are very cool, but ultimately, what's the pursuit of
28:04
Speaker 1: paleontology to to put together the piece of the puzzle
28:09
Speaker 1: of how we got here? Right? I mean that's what
28:12
Speaker 1: I think. Yeah, that's my understanding as well. Yeah, you
28:15
Speaker 1: can learn a lot by not only finding the fossil,
28:18
Speaker 1: but finding what was with the fossil in that same strata. Ah.
28:24
Speaker 1: I can tell you like, hey, this is a t
28:26
Speaker 1: rex bone, and there's also a bit of pine tree,
28:30
Speaker 1: so we know pine trees were around, and they may
28:33
Speaker 1: have eaten pine trees. Well not t rex because they
28:35
Speaker 1: were carnivores, right, um, yeah, they were herbivore. Let's say,
28:40
Speaker 1: you know what I mean, Abronosaurus sure. Um. And ultimately
28:44
Speaker 1: all of these fossils come together, plant and well everything
28:47
Speaker 1: that we can get our hands on to form what
28:50
Speaker 1: is called the fossil record, right, and this is basically
28:53
Speaker 1: the record of life on Earth. Uh. It's also used
28:56
Speaker 1: to support evolution big time. And uh, it's here that
29:00
Speaker 1: paleontology gets most contentious, right, yeah, sure, because there's um
29:08
Speaker 1: the the idea that beings evolve if you go far
29:12
Speaker 1: enough back from a single common ancestor, right, And so
29:16
Speaker 1: if we can put together a complete fossil record, we
29:20
Speaker 1: would be able to see how everything alive today evolved
29:23
Speaker 1: from this common ancestor or common ancestors. Right. Yeah. The
29:28
Speaker 1: problem is fossil records incomplete, and one of the really
29:32
Speaker 1: key parts that it's often missing are called transitional fossils. Right,
29:36
Speaker 1: My favorite kind of fossil, Josh, is a transitional fossil.
29:40
Speaker 1: And one example Tracy used was the baleen whale. Uh. There,
29:44
Speaker 1: there's a picture of one actually in the article twenty
29:46
Speaker 1: five million year old fossil of a baleen whale with
29:49
Speaker 1: sharp teeth. Um, today's bailing whales don't have sharp teeth,
29:53
Speaker 1: but we know that once before this had sharp teeth
29:56
Speaker 1: and legs. So this is a transitional fossil that shows, well,
30:00
Speaker 1: they used to have legs and sharp teeth, then they
30:02
Speaker 1: just had sharp teeth, and now they don't have legs
30:05
Speaker 1: or sharp teeth. They're defenseless, which is why they're bailing whales,
30:08
Speaker 1: right and not sharks or Megalodon's right. Um, and so
30:13
Speaker 1: a transitional fossil is one that that pops up between
30:16
Speaker 1: old and new, and it makes sense. Our understanding of
30:20
Speaker 1: evolution is that it takes a little while, and UM,
30:24
Speaker 1: something like teeth aren't just gonna go away in one generation.
30:28
Speaker 1: It's gonna take more and more and more, and then UM,
30:30
Speaker 1: we should be able to find them along the way
30:32
Speaker 1: where maybe the teeth gets smaller. There's fewer and fewer
30:35
Speaker 1: UM baling whale teeth in the average baling whale mouth,
30:40
Speaker 1: and you're putting together the puzzle exactly. Um. Again, the
30:44
Speaker 1: fossil records a little incomplete, and there aren't as many
30:47
Speaker 1: transitional fossils as I think people would like to UM
30:51
Speaker 1: have tied all together, right, UM, and then some of
30:54
Speaker 1: the uh, some of the explanations are probably the most
30:57
Speaker 1: famous explanation for this is that UM evolution isn't gradual.
31:02
Speaker 1: I think it's Stephen J. Gould came up with the
31:04
Speaker 1: idea of punctuated equilibrium, and that is basically that UM
31:09
Speaker 1: evolution takes place suddenly in these huge quick fits and starts,
31:15
Speaker 1: which would explain why there's not like teeth don't go
31:18
Speaker 1: away in a generation, but they go away a lot
31:21
Speaker 1: faster than we used to suspect. And that's why these
31:26
Speaker 1: um fossils um accompanied with the idea that not every
31:30
Speaker 1: animal that's ever died has become fossilized, explained why there's
31:33
Speaker 1: huge gaps in the fossil record, which will inevitably always
31:36
Speaker 1: be incomplete. Is that a hypothesis at this point? I
31:41
Speaker 1: guess it is not a theory yet I don't. I
31:45
Speaker 1: don't think so. I think it is a hypothesis. I
31:47
Speaker 1: got one more thing, Okay, I'd like to finish with
31:50
Speaker 1: my favorite kind of fossil, and that is a living fossil.
31:54
Speaker 1: And that, Josh, is when you've got a plant or
31:57
Speaker 1: animal that looks so much like ancient fossils that they
32:02
Speaker 1: consider a living fossil. Allah, the horseshoe crab, right, apparently
32:07
Speaker 1: the horseshoe crab has not changed. Didn't need too, It's perfect.
32:10
Speaker 1: Look at it, it's gorgeous. What else? Oh, genk baloba plants?
32:15
Speaker 1: And then a word that I don't know of, the
32:18
Speaker 1: ceila cant. What is that? Uh? It's this horrid looking
32:22
Speaker 1: fish that they remember that VW commercial where he's like,
32:26
Speaker 1: it's like the Cela camp and the guys like what
32:28
Speaker 1: they're looking in the trunk and he's like a full
32:30
Speaker 1: size spare tire and he's like, it's like a Cela.
32:33
Speaker 1: Can't They used to think it was extinct. There was
32:35
Speaker 1: a fish, and then they found it, like in the
32:37
Speaker 1: nineteen thirties again, but it's this dinosaur looking fish. Oh,
32:41
Speaker 1: I think I've seen him that they thought was extinct
32:43
Speaker 1: for millions of years and they called him I think
32:45
Speaker 1: in South America, off the coast of South America, and
32:48
Speaker 1: they're still around living Saul and the Horseshoe Crab and
32:52
Speaker 1: Stephen j. Could in the gek Baloba. Well, it's it
32:56
Speaker 1: for fossils, right, That's all I have. I think we've
32:58
Speaker 1: got the point across. That's an overview. A fossil is
33:00
Speaker 1: a rock. Just remember that, Okay if you want to
33:04
Speaker 1: learn more about fossils um Seriously, this is one of
33:07
Speaker 1: the better articles on the site. Tracy did a great
33:10
Speaker 1: job with it. Type fossils into the search bar a
33:14
Speaker 1: handy search bar, and how stuff works dot com, which
33:17
Speaker 1: means it's time for listener mail. Josh. We made a
33:22
Speaker 1: young girl cry. That's what I'm gonna call this one. Okay,
33:26
Speaker 1: It's probably happened more than once. Hi, guys and Jerry.
33:29
Speaker 1: My name is Ali. I'm from Indiana. I was in
33:32
Speaker 1: the I S s M, a band contest, playing a
33:35
Speaker 1: difficult marimba solo today. I was pretty nervous, but being
33:39
Speaker 1: first chair and the only female percussionist in my school
33:42
Speaker 1: really brought up my confidence. I went in, I choked
33:45
Speaker 1: and I stumbled through my piece. You get a gold,
33:48
Speaker 1: silver bronze or a participation medal. Got the bronze, which
33:53
Speaker 1: is equivalent to a score of an F. I was
33:57
Speaker 1: really upset. Wait, what is participating that sub f? I
34:01
Speaker 1: didn't even know they made metals. I thought was is
34:03
Speaker 1: the ribbon? It's probably a ribbon. I was really upset.
34:06
Speaker 1: I got home. I was trying to cheer myself up
34:08
Speaker 1: by listening to your podcast on What's the Deal with Sinkholes.
34:11
Speaker 1: I really love the show and I've listened almost everyone.
34:13
Speaker 1: But in the beginning, you guys talked about how much
34:16
Speaker 1: the bronze medals suck. Remember that. Oh yeah, so we
34:19
Speaker 1: didn't liftro spirits very much, Josh and Chuck. I just
34:22
Speaker 1: want to let you know that the two of you
34:23
Speaker 1: made me cry then from Ali and I has since
34:26
Speaker 1: written Alie back and apologized, and she said that she's
34:29
Speaker 1: feeling much better now and uh, it wasn't our fault.
34:32
Speaker 1: And I told her that I've choked under pressure many
34:35
Speaker 1: times in my life and it happens, and it will
34:39
Speaker 1: happen again, and it doesn't mean you don't have the
34:42
Speaker 1: goods every single time, but you know you pick yourself up.
34:47
Speaker 1: It sounds like you gave her some good advice choke.
34:48
Speaker 1: I think so. She seemed receptive to it. It's like
34:51
Speaker 1: a sweet girl. I think that's an excellent lead in.
34:54
Speaker 1: If you have a story about choking, not physically choking,
34:58
Speaker 1: but you there's something you good at and you didn't
35:01
Speaker 1: do it. Well, say you're a television reporter in Los
35:04
Speaker 1: Angeles and you're supposed to report on the Grammys like
35:08
Speaker 1: that to your podcast, and you have to do a
35:10
Speaker 1: show about the sun to give one too, but we
35:13
Speaker 1: want to hear about it. You can send it to
35:15
Speaker 1: us via email. Just type in where it says to
35:19
Speaker 1: stuff podcast at how stuff works dot com for more
35:27
Speaker 1: on this and thousands of other topics. Is it how
35:29
Speaker 1: stuff works dot com To learn more about the podcast,
35:32
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35:34
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