DNA Science Challenges Sweden's Famed Botanist This month marks the 300th birthday of Carl Linnaeus, Sweden's beloved botanist who gave order to the plant and animal kingdoms. But modern science is complicating Linnaeus' ranking system.
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DNA Science Challenges Sweden's Famed Botanist

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DNA Science Challenges Sweden's Famed Botanist

DNA Science Challenges Sweden's Famed Botanist

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This is ALL THINGS CONSIDERED from NPR News. I'm Debbie Elliott.

If you can sit on a park bench or stroll through the woods and identify what's a mammal, what's a flowering tree, or what's an insect, you have Carl Linnaeus to thank, and maybe your science teachers as well. Linnaeus would have turned 300 years old this Wednesday.

The Swedish botanist was the father of modern taxonomy. He named and classified about 12,000 plants and animals, and he invented the basic framework of the system biologists still use today to classify all of life. This week, Linnaeus' fans plan some 1,600 birthday bashes across the world, from New South Wales to his native Sweden.

NPR producer Addie Goss explains why all of the fuss.

ADDIE GOSS: It's an exciting week to be Swedish. There will be black tie dinners and Linnaeus cream cakes. The Japanese emperor is even coming in for a visit. Andres Bjorck is the governor of Uppsala, where Carl Linnaeus lived for 50 years.

Governor ANDRES BJORCK (Uppsala, Sweden): The whole city will be absolutely crowded next week especially on Wednesday with festivals, singers, and so on, and so on. So the whole city will be more or less boiling of joy.

GOSS: For a 300-year-old guy, Linnaeus still has a big influence. For one, he developed our system for naming organisms, the binomial system - two words -like homo sapiens. He grouped these organisms: birds by their beaks, insects by their wings. And then he ranked the groups: class, order, genus, species. Even today, high school students are learning the mnemonics for these ranks.

The ranking system has more or less survived 300 years. Its structure is still sound, but just like a 300-year-old house, it's required some renovation. To see why, I visited Kevin de Queiroz.

Mr. KEVIN DE QUEIROZ (Curator/Zoologist, National Museum of Natural History): Where is the light?

GOSS: De Queiroz is a zoologist for the Smithsonian here in Washington. He curates the reptiles and amphibian collection in the basement of the museum of Natural History, and it's huge.

Every time you turn on the light I see another mile of reptiles.

Mr. DE QUEIROZ: This is probably the largest collection of amphibians and reptiles in the world.

GOSS: Five hundred and sixty thousand jars. Each holds a different species or reptile or amphibian floating in alcohol.

Mr. DE QUEIROZ: So as we're walking down this hall, we have the lizards on your left...

GOSS: The scientists who organized this collection grouped the animals by morphology: the structure of their tongues, the shape of their skulls, whether or not their jaws come apart.

Mr. DE QUEIROZ: But now, we get to the end here, and now we've got a, sort of, mixture of weird snakes and lizard-like things that we don't really know where they fit in.

GOSS: De Queiroz calls this the mystery aisle; the lizards and snakes on these shelves are just too weird to be sorted by their scales and skulls.

Mr. DE QUEIROZ: Here are the Amphisbaenia.

GOSS: De Queiroz pulls a jar out off the top shelf, opens it up, and tugs at this long thing.

Mr. DE QUEIROZ: And you can see sometimes the way they were folded doesn't exactly fit well into the - yeah, so you might see why they call that worm a lizard.

GOSS: It's like a giant, bloated earthworm with scales. Today is a big day for the Amphisbaenians. Until recently, no one knew where they fit on the reptilian tree of life. But now, scientists have a new tool. They look at the species' DNA. It turns out that Amphisbaenians share a lot of DNA with some pretty, typical-looking lizards with feet that live in the U.S. and Europe.

Mr. DE QUEIROZ: Well, so now, now that we have a better idea about who they're related to, we should probably rearrange the collection so that they're close to the things that they're closely related to.

GOSS: In cases like this, DNA analysis is shaking up the tree of life, moving creatures from one branch to another. Other times, DNA studies help create new branches altogether. Linnaeus grouped all of life into four different ranks. Now, De Queiroz says, scientists use dozens.

Mr. DE QUEIROZ: As we've discovered more and more about how things are related to each other, seven ranks just weren't enough to deal with it. So now, you know, we have super-orders, sub-families, super-families, tribes.

GOSS: It turns out life is even more complicated than Linnaeus thought. But, De Queiroz says, Linnaeus got one thing perfectly right. He looked around him and saw that there is order in nature. And Darwin agreed with him a hundred years later. If he hadn't, we might not be celebrating Linnaeus today.

Addie Goss, NPR News, Washington.

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