新托福考试必备：新托福TPO（1-24）听力原文文本TPO9

　　L: OK, so last time, we covered the dances honey bees due to indicate where
　　food can be found and the calls and sounds of different types of birds. Today,
　　I'd like to look at some communication systems found in mammals, particularly
　　in primates, such as orangutans, chimpanzees, gorillas... Yes, Thomas?

　　T: Excuse me, Professor. But when you talk about gorilla language, do you
　　mean like, those experiments where humans taught them sign language or a
　　language like...

　　L: OK, wait just a minute. Now, who in this class heard me use the word
　　"language"? No one I hope. What we're talking about here, are systems of
　　communication, all right?

　　T: Oh, sorry, communication, right. But could you maybe, like, clarify with the
　　differences?

　　L: Of course, that's a fair question. OK, well, to start with, let's make it clear
　　that language is a type of communication, not the other way around. OK, so all
　　communication systems, language included, have certain features in common.
　　For example, the signals used to communicate from the bee's dance
　　movements, to the word and sentences found in human languages. All these
　　signals convey meaning. And all communication systems serve a purpose, a
　　pragmatic function of some sort. Warning of danger perhaps or offering other
　　needed information. But there're several features peculiar to human language
　　that have, for the most part, never been found in the communication system of
　　any other species. For one thing, learn ability. Animals have instinctive
　　communication systems. When a dog, a puppy gets to certain age, it's able to
　　bark. It barks without having to learn how from other dogs, it just barks. But
　　much of human language has to be learned from other humans. What else
　　makes human language unique? What makes it different from animal
　　communication? Debber?

　　D: How about grammar? Like having verbs, nouns, adjectives?

　　L: OK, that's another feature. And it's a good example...

　　D: I mean I mention this cause like in my biology class last year, I kind of
　　remember talking about a study on prairie dogs, where, I think the researchers
　　claimed that the warning cries of prairie dogs constitute language, because
　　they have this, different parts of speech. You know, like nouns, to name the
　　type of predator they spotted, adjectives to describe its size and shape,
　　verbs..., but now it seems like...

　　L: All right, hold on a moment. I'm familiar with the study you're talking about.
　　And for those of you who don't know, prairie dogs are not actually dogs.
　　They're type of rodent who burrows in the ground and the grasslands of the
　　west United States and Mexico. And in this study, the researchers looked at
　　the high-pitched barks a prairie dog makes when it spots predator. And from
　　this they made some pretty.., well, they made some claims about these calls
　　qualifying as an actual language, with its own primitive grammar. But actually,
　　these warning calls are no different from those found among certain types of
　　monkeys. Well, let's not even get into the question whether concepts like noun
　　and verb can be meaningfully applied to animal communication. Another thing
　　that distinguishes a real language is a property we call "discreteness". In other
　　words, messages are built up out of smaller parts, sentences out of words,
　　words out of individual sounds, etc. Now maybe you could say that the prairie
　　dog's message is built from smaller parts, like say for example, our prairie
　　dogs spot a predator, a big coyote approaching rapidly. So the prairie dog
　　makes a call that means "coyote", then one that means "large", and then
　　another one to indicate its speed. But you really suppose it makes any
　　difference what order these calls come in? No. But the discrete units that make
　　up language can be put together in different ways. Those smaller parts can be
　　used to form an infinite number of messages, including messages that are
　　completely novel, that have never been expressed before. For example, we
　　can differentiate between: "A large coyote moves fast." and say "Move the
　　large coyote fast." or "Move fast, large coyote.", and I truly doubt whether
　　anyone has ever uttered either of these sentences before. Human language is
　　productive and open-ended communication system, whereas no other
　　communication system has this property. And another feature of language
　　that's not displayed by any form of animal communication is what we call
　　"displacement". That is, language is abstract enough that we can talk about
　　things that aren't present here and now. Things like "My friend Jo is not in the
　　room." or "It will probably rain next Thursday." Prairie dogs may be able to tell
　　you about a hawk at circling over head right now, but they never show any
　　inclination to describe the one they saw last week.