This is a drama. It is written to be performed, so perform it. People should perform it in pairs, one member of the pair being Bing and one being Bong. So begin by deciding who will be Bing and who will be Bong. Read your part aloud and with feeling. When there are stage directions [marked by brackets and italics] carry them out.

Bing and Bong are friends who like to think about interesting things and discuss them with one another. That is why they take biology classes, because there are so many interesting things to see and discuss. In this case the two friends have just returned from a visit to the cryptosphere, that fascinating world in the leaf litter of a forest,  where they have seen all kinds of wonderful creatures.

Bing: Well, Bong. That was quite an adventure. We certainly did see all kinds of wonderful creatures!

Bong: Yes, indeed, Bing. So many things in so small a space. The experience has changed the way I think about walking on leaves. But it was also overwhelming, you know. I found it very difficult to wrap my mind around so many different creatures.

Bing: [Muttering to himself] Especially when you have so little wrapping! [Then aloud to Bong] As a matter of fact, the same sort of thing happened to people in the 16th and 17th centuries as they began to explore the world. Europeans hadn't traveled much until then, and they were pretty much used to the small range of plants and animals they saw around their home. But when they went out into the world they were flabbergasted by the diversity they encountered.

Bong: Having journeyed to the cryptosphere, I can well imagine. I see now why Linneaus was so important to early biology.

Bing: Yes, indeed, he was important alright. He gave everything a name, as I understand it.

Bong: Not just a name, Bing. Linneaus devised a system in which every creature had two names, first a genus and then a species name. We still use that system today, and since its intent is to make things orderly, there are all sorts of rules about these names. The first of the two names is called the genus name, and it's always capitalized. The second name is called the "species epithet" and it...

Bing: Wait a minute, Bong! A species what...species epithet? I thought "epithet" meant "insult."

Bong: [Looking peeved] It can, but in this case it doesn't. Honestly, Bing, you come up with the weirdest ideas sometimes. Anyway, the species epithet is not capitalized, and both the Genus and the species name are either italicized or underlined. The names are in Latin or Greek and there are rules about that too.

Bing: Well, anyway, all the creatures got these binomials or two names. I can see that as helpful on one level, but it seems to me that in the end, once all the animals and plants were named, we'd be where we were before. Now we're confronted with a huge diversity of names and twice as many as the number of creatures.

Bong: True enough. But in many ways the names were the least important part of Linneaus' system. In addition to the binomials Linneaus also constructed a system of nested hierarchies.

Bing: Sounds like the name of a bird, Bong -- "Look, over there! A whole flock of nested hierarchies just coming over the trees."

Bong: [Taking on that peeved look again] Not in a very serious mood today, are you, Bing. No, the point is that Linneaus set up a classification system with a set of categories in which each category contains all the categories below it and is contained in all the categories above it.

Bing: Oh, I know about this -- this is that Kingdom - Phylum - Class - Order - Family - Genus - Species stuff, isn't it.

Bong: Very good. But it isn't just that there are categories. The categories are nested. For example, there is a family of beetles called the "Cucurlonidae," the weevils. This family is made up of several genera. All those genera can be classified as Cucurlonidae because they are more like one another than are genera in other families. Then the Cucurlonidae are in the order Coleoptera, the beetles, and they and all the other beetle families resemble each other more than they do flies or wasps or earwigs. But the flies, wasps and earwigs are more like beetles and other insects in the class Insecta than they are like other classes of the Phylum Arthropoda. As you go down the levels of the system, the various groups become more and more like one another.

Bing: A very tidy system that Linneaus devised. But I understand that in his day some of the categories w ere sort of odd -- like didn't he have a group "Vermes", the worms for all the long thin animals including both earthworms and snakes?

Bong: Yes, he did. But that is because Linneaus was a classifier without a sense of phylogeny. He understood taxonomy, but not systematics.

Bing: You like to say that sort of thing, don't you, Bong. But what does that mean?

Bong: Well, Linneaus was interested in classifying, but he didn't have a concept of evolution. He grouped organisms together according to their resemblances, but he didn't think in terms of relatedness. When we think of organisms being related, we mean they had a common ancestor, but Linneaus didn't mean that since he didn't think in terms of modification by descent.

Bing: [Leaping to his feet] Hey, this is a really interesting idea, Bong. You come up with those every now and then. You're saying that Linneaus classified things because they looked alike but not necessarily because they were alike. I'd like to know more about that.

Bong: Well, you're going to get your wish, Bing. Here comes the professor.

Donald Cronkite, September 11, 1997