首页
登录
职称英语
Listen to part of a lecture in a zoology class.Professor:As you know from the
Listen to part of a lecture in a zoology class.Professor:As you know from the
游客
2025-02-05
2
管理
问题
Listen to part of a lecture in a zoology class.
Professor:
As you know from the textbook, mimicry isn’t limited to insects, but it’s most common among them, and by mimicry I’m referring to the likeness between two insects that aren’t closely related but look very much alike. The insects that engage in mimicry are usually very brightly colored. One of the insects, the one that’s characterized by an unpleasant taste, a bad smell, a sting or bite, that insect is called the model. The mimic looks like the model but doesn’t share the characteristic that protects the model from predators. But, of course, the predators associate the color pattern or some other trait with the unpleasant characteristic and leave both insects alone.
Henry Bates was one of the first naturalists who noticed that some butterflies that closely resembled each other were actually unrelated, so mimicry in which one species copies another is called Batesian mimicry. I have some lab specimens of a few common mimics in the cases here in the front of the room, and I want you to have a chance to look at them before the end of the class. There’s a day flying moth with brown and white and yellow markings. And this moth is the model because it has a very unpleasant taste and tends to be avoided by moth eaters. But you’ll notice that the swallowtail butterfly mounted beside it has very similar coloration, and actually the swallowtail doesn’t have the unpleasant taste at all. Another example is the monarch butterfly, which is probably more familiar to you since they pass through this area when they’re migrating. But you may not know that they have a very nasty taste because I seriously doubt that any of you have eaten one. But for the predators who do eat butterflies, this orange and black pattern on the monarch is a warning signal not to sample it. So, the viceroy butterfly here is a mimic. Same type of coloring but no nasty taste. Nevertheless, the viceroy isn’t bothered by predators either, because it’s mistaken for the monarch. So how does a predator know that the day flying moth and the monarch aren’t good to eat? Well, a bird only has to eat one to start avoiding them all—models and mimics.
A stinging bumblebee is another model insect. The sting is painful and occasionally even fatal for predators. So there are a large number of mimics. For example, there’s a beetle that mimics bumblebees by beating its wings to make noise, and the astonishing thing is that it’s able to do this at the same rate as the bumblebee so exactly the same buzzing sound is created. I don’t have a specimen of that beetle, but I do have a specimen of the hoverfly, which is a mimic of the honeybee, and it makes a similar buzzing sound, too. When you compare the bee with the fly, you’ll notice that the honeybee has two sets of wings, and the hoverfly has only one set of wings, but as you can imagine, the noise and the more or less similar body and color will keep most predators from approaching closely enough to count the wings.
Some insects without stingers have body parts that mimic the sharp stinger of wasps or bees. Although the hawk moth is harmless, it has a bundle of hairs that protrudes from the rear of its body. The actual purpose of these hairs is to spread scent, but to predators, the bundle mimics a stinger closely enough to keep them away, especially if the hawk moth is moving in a threatening way as if it were about to sting. There’s a hawk moth here in the case, and to me at least, it doesn’t look that much like the wasp mounted beside it, but remember when you’re looking at a specimen, it’s stationary, and in nature the movement is also part of the mimicry.
Oh, here’s a specimen of an ant, and this is interesting. Another naturalist, Fritz Muller, hypothesized that similarity among a large number of species could help protect all of them. Here’s what he meant. After a few battles with a stinging or biting ant, especially when the entire colony comes to the aid of the ant being attacked, a predator will learn to avoid ants, even those that don’t sting or bite, because they all look alike and the predator associates the bad experience with the group. And by extension, the predator will also avoid insects that mimic ants, like harmless beetles and spiders.
Look at this.
I have a drawing of a specimen of a stinging ant beside a specimen of a brownish spider and the front legs of the spider are mounted so they look more like antennae because that’s just what the spider does to mimic an ant. That way it appears to have six legs like an ant instead of eight like a spider.
Okay, we have about ten minutes left, and I want you to take this opportunity to look at the specimen cases here in the front of the room. I’ll be available for questions if you have them. How about forming two lines on either side of the cases so more of you can see at the same time? [br] D A bumblebee
Listen to part of a lecture in a zoology class.
Professor:
As you know from the textbook, mimicry isn’t limited to insects, but it’s most common among them, and by mimicry I’m referring to the likeness between two insects that aren’t closely related but look very much alike. The insects that engage in mimicry are usually very brightly colored. One of the insects, the one that’s characterized by an unpleasant taste, a bad smell, a sting or bite, that insect is called the model. The mimic looks like the model but doesn’t share the characteristic that protects the model from predators. But, of course, the predators associate the color pattern or some other trait with the unpleasant characteristic and leave both insects alone.
Henry Bates was one of the first naturalists who noticed that some butterflies that closely resembled each other were actually unrelated, so mimicry in which one species copies another is called Batesian mimicry. I have some lab specimens of a few common mimics in the cases here in the front of the room, and I want you to have a chance to look at them before the end of the class. There’s a day flying moth with brown and white and yellow markings. And this moth is the model because it has a very unpleasant taste and tends to be avoided by moth eaters. But you’ll notice that the swallowtail butterfly mounted beside it has very similar coloration, and actually the swallowtail doesn’t have the unpleasant taste at all. Another example is the monarch butterfly, which is probably more familiar to you since they pass through this area when they’re migrating. But you may not know that they have a very nasty taste because I seriously doubt that any of you have eaten one. But for the predators who do eat butterflies, this orange and black pattern on the monarch is a warning signal not to sample it. So, the viceroy butterfly here is a mimic. Same type of coloring but no nasty taste. Nevertheless, the viceroy isn’t bothered by predators either, because it’s mistaken for the monarch. So how does a predator know that the day flying moth and the monarch aren’t good to eat? Well, a bird only has to eat one to start avoiding them all—models and mimics.
A stinging bumblebee is another model insect. The sting is painful and occasionally even fatal for predators. So there are a large number of mimics. For example, there’s a beetle that mimics bumblebees by beating its wings to make noise, and the astonishing thing is that it’s able to do this at the same rate as the bumblebee so exactly the same buzzing sound is created. I don’t have a specimen of that beetle, but I do have a specimen of the hoverfly, which is a mimic of the honeybee, and it makes a similar buzzing sound, too. When you compare the bee with the fly, you’ll notice that the honeybee has two sets of wings, and the hoverfly has only one set of wings, but as you can imagine, the noise and the more or less similar body and color will keep most predators from approaching closely enough to count the wings.
Some insects without stingers have body parts that mimic the sharp stinger of wasps or bees. Although the hawk moth is harmless, it has a bundle of hairs that protrudes from the rear of its body. The actual purpose of these hairs is to spread scent, but to predators, the bundle mimics a stinger closely enough to keep them away, especially if the hawk moth is moving in a threatening way as if it were about to sting. There’s a hawk moth here in the case, and to me at least, it doesn’t look that much like the wasp mounted beside it, but remember when you’re looking at a specimen, it’s stationary, and in nature the movement is also part of the mimicry.
Oh, here’s a specimen of an ant, and this is interesting. Another naturalist, Fritz Muller, hypothesized that similarity among a large number of species could help protect all of them. Here’s what he meant. After a few battles with a stinging or biting ant, especially when the entire colony comes to the aid of the ant being attacked, a predator will learn to avoid ants, even those that don’t sting or bite, because they all look alike and the predator associates the bad experience with the group. And by extension, the predator will also avoid insects that mimic ants, like harmless beetles and spiders.
Look at this.
I have a drawing of a specimen of a stinging ant beside a specimen of a brownish spider and the front legs of the spider are mounted so they look more like antennae because that’s just what the spider does to mimic an ant. That way it appears to have six legs like an ant instead of eight like a spider.
Okay, we have about ten minutes left, and I want you to take this opportunity to look at the specimen cases here in the front of the room. I’ll be available for questions if you have them. How about forming two lines on either side of the cases so more of you can see at the same time?
选项
A、Mimic
B、Model
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3944289.html
相关试题推荐
Whydoesthemangotoseehisprofessor?[br][originaltext]Listentoaconver
Listentopartofalectureinazoologyclass.Professor:Asyouknowfromthe
Listentopartofalectureinazoologyclass.Professor:Asyouknowfromthe
Listentopartofalectureinazoologyclass.Professor:Asyouknowfromthe
Listentopartofalectureinazoologyclass.Professor:Asyouknowfromthe
Listentopartofalectureinazoologyclass.Professor:Asyouknowfromthe
Listentopartofalectureinazoologyclass.Professor:Asyouknowfromthe
Listentopartofalectureinazoologyclass.Professor:Asyouknowfromthe
Listentopartofalectureinazoologyclass.Professor:Asyouknowfromthe
Listentoaconversationoncampusbetweentwostudents.Man:Waitup.Ineed
随机试题
[originaltext]M:It’ssaidyouandTinaareenthusiasticaboutyogaclass,aren
Ifchildrencouldstepintotheshoesofavictimofbullying,wouldtheybe
从四个选项中选择最合适的一个填入问号处,使之呈现一定的规律性。( ) A.A
云服务是指通过云平台提供的云计算服务。其中,云计算类型不包含( )。A.基础设
欲清热燥湿,和胃安胎,用治痢疾、湿热、胎动不安等症宜选用A:黄芩B:酒黄芩C
初孕妇,孕33周,近1周自觉头晕、乏力、心悸及食欲减退。查体:面色苍白,心率10
下列说法中,不符合我国行政许可法规定的是( )。A.税务机关通过办税服务窗口向申
工程项目建设周期可分为()。A.前期阶段 B.准备阶段 C.实施阶段 D.
A
在建筑安装工程费中,不属于施工机具使用费的是()。A.折旧费 B.经常修理费
最新回复
(
0
)