The wacky history of cell theory - Lauren Royal-Woods

7,088,986 views ・ 2012-06-04

TED-Ed


Please double-click on the English subtitles below to play the video.

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One of the great things about science
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is that when scientists make a discovery,
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it's not always in a prescribed manner,
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as in, only in a laboratory under strict settings,
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with white lab coats
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and all sorts of neat science gizmos that go, "Beep!"
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In reality,
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the events and people involved
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in some of the major scientific discoveries
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are as weird and varied as they get.
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My case in point:
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The Weird History of the Cell Theory.
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There are three parts to the cell theory.
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One: all organisms are composed of one or more cells.
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Two: the cell is the basic unit of structure
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and organization in organisms.
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And three: all cells come from preexisting cells.
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To be honest, this all sounds incredibly boring
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until you dig a little deeper
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into how the world of microscopic organisms,
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and this theory came to be.
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It all started in the early 1600s in the Netherlands,
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where a spectacle maker named Zacharias Janssen
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is said to have come up with the first compound microscope,
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along with the first telescope.
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Both claims are often disputed,
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as apparently he wasn't the only bored guy
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with a ton of glass lenses to play with at the time.
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Despite this,
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the microscope soon became a hot item
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that every naturalist or scientist at the time wanted to play with,
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making it much like the iPad of its day.
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One such person
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was a fellow Dutchman by the name of Anton van Leeuwenhoek,
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who heard about these microscope doohickeys,
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and instead of going out and buying one,
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he decided to make his own.
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And it was a strange little contraption indeed,
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as it looked more like a tiny paddle the size of a sunglass lens.
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If he had stuck two together,
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it probably would have made a wicked set of sunglasses
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that you couldn't see much out of.
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Anyhoo, once Leeuwenhoek had his microscope ready,
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he went to town,
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looking at anything and everything he could with them,
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including the gunk on his teeth.
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Yes, you heard right.
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He actually discovered bacteria
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by looking at dental scrapings,
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which, when you keep in mind
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that people didn't brush their teeth much -- if at all -- back then,
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he must have had a lovely bunch of bacteria to look at.
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When he wrote about his discovery,
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he didn't call them bacteria, as we know them today.
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But he called them "animalcules,"
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because they looked like little animals to him.
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While Leeuwenhoek was staring at his teeth gunk,
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he was also sending letters to a scientific colleague in England,
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by the name of Robert Hooke.
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Hooke was a guy who really loved all aspects of science,
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so he dabbled in a little bit of everything, including physics,
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chemistry and biology.
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Thus it is Hooke who we can thank for the term "the cell,"
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as he was looking at a piece of cork under his microscope,
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and the little chambers he saw reminded him of cells,
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or the rooms monks slept in in their monasteries.
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Think college dorm rooms,
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but without the TVs, computers and really annoying roommates.
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Hooke was something of an underappreciated scientist
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of his day --
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something he brought upon himself,
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as he made the mistake of locking horns
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with one of the most famous scientists ever, Sir Isaac Newton.
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Remember when I said Hooke dabbled in many different fields?
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Well, after Newton published a groundbreaking book
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on how planets move due to gravity,
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Hooke made the claim
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that Newton had been inspired by Hooke's work in physics.
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Newton, to say the least, did not like that,
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which sparked a tense relationship between the two
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that lasted even after Hooke died,
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as quite a bit of Hooke's research -- as well as his only portrait --
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was ... misplaced, due to Newton.
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Much of it was rediscovered, thankfully, after Newton's time,
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but not his portrait,
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as, sadly, no one knows what Robert Hooke looked like.
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Fast-forward to the 1800s,
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where two German scientists discovered something
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that today we might find rather obvious,
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but helped tie together what we now know as the cell theory.
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The first scientist was Matthias Schleiden,
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a botanist who liked to study plants under a microscope.
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From his years of studying different plant species,
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it finally dawned on him
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that every single plant he had looked at
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were all made of cells.
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At the same time,
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on the other end of Germany was Theodor Schwann,
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a scientist who not only studied slides of animal cells
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under the microscope
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and got a special type of nerve cell named after him,
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but also invented rebreathers for firefighters,
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and had a kickin' pair of sideburns.
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After studying animal cells for a while,
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he, too, came to the conclusion
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that all animals were made of cells.
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Immediately, he reached out via snail mail,
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as Twitter had yet to be invented,
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to other scientists working in the same field with Schleiden,
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who got back to him,
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and the two started working on the beginnings of the cell theory.
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A bone of contention arose between them.
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As for the last part of the cell theory --
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that cells come from preexisting cells --
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Schleiden didn't exactly subscribe to that thought,
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as he swore cells came from free-cell formation,
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where they just kind of spontaneously crystallized into existence.
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That's when another scientist named Rudolph Virchow,
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stepped in with research showing that cells did come from other cells,
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research that was actually -- hmm ... How to put it? --
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"borrowed without permission"
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from a Jewish scientist by the name of Robert Remak,
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which led to two more feuding scientists.
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Thus, from teeth gunk to torquing off Newton,
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crystallization to Schwann cells,
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the cell theory came to be an important part of biology today.
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Some things we know about science today may seem boring,
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but how we came to know them is incredibly fascinating.
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So if something bores you,
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dig deeper.
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It's probably got a really weird story behind it somewhere.
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