字幕列表 影片播放 列印英文字幕 Can you see the bug? Probably can’t, can you? Doing its job. Hey everybody, it’s Maddie Sofia from NPR and Joe’s Big Idea, and I’m here at the Smithsonian Museum of Natural History hanging out with some bugs. These critters are truly nature’s masters of disguise. Hannah Wood has joined us. Hannah is an arachnologist here at the Smithsonian, and Hannah’s going to take us backstage to see some of the collections. How many insects do you guys have? We have about 35 million specimens of insects and arachnids. 35 million! That’s a lot of bugs. OK and arachnids, sure. Spider lady. Why would an insect want to mimic something else? Could be several reasons why. Some of the more common reasons would be because they’re mimicking something that has venom or is potentially dangerous and so they get the benefit by looking the same way. For example, in spiders, you have ant-mimic spiders where they look like other ants, they live amongst them and this allows them to prey on other ant species. But insects don’t choose to become mimics, and it doesn’t happen overnight. Let’s look at our walking leaf buddy from earlier. Random differences in DNA lead to unique traits. And sometimes, these traits do not work out so well. But, occasionally a trait might help them survive. The ones that survive make babies, passing down their unique DNA. And the trait sticks around in the population. That’s a bug, not a leaf. That’s a bug! And here we have an Australian walking stick, and these insects look a little bit like tree bark. Look at this! That looks like part of a tree. We’re going to look at a giant Malaysian walking stick. And here we have an Asian dead leaf mantis. And these insects, they look like dead leaves. All right. Well, OK. Sure, yeah, no take your time, wherever you want. He’s putting out his little feelers for a little high-five. boop! Arachnologist. Have you always liked spiders? I have always not disliked them, yeah. Just to be clear, everybody starts off with just not hating spiders. I was fascinated with them. I took this insect taxonomy course, and from the moment I saw an insect under a microscope, I just knew, “Wow this is what I want to do.” What is this mimicking? So this beautiful little moth here is mimicking bird poop. It’s a poop mimic! So, I’m going to go out on a limb, and say that these are leaf mimics? Yes. Are insects, bugs still evolving? I mean are humans playing a role in that kind of deal? I mean everything’s still evolving. Humans have certainly altered the environment in a way that other organisms have changed the way they look or their behavior. Such as those moths during the industrial revolution. Hannah is talking about the peppered moth. They can be speckled white or black. During the Industrial Revolution, there was so much pollution that soot covered the trees. Suddenly, the white moths were pretty easy to spot. By the end of the century, almost 100 percent of the peppered moths left in the city were black. But, after we cleaned up the environment in the 1950s, the white moths made a comeback. Our world and the millions of species of insects that call it home are still evolving. Who knows what they’ll mimic next. Hi I’m Adam Cole and this is Skunk Bear, NPR’s Science show. I’m a mimic, like you, yeah. Oh, OK. And we’re excited to share this new series. Maddie About Science is a part of Joe’s Big Idea, and we tell the stories about the people and the process of science. If you want to check out what we’re doing, click here. And please subscribe to our YouTube channel right here. I know you’re not a leaf, you’re not tricking anybody. Don’t turn away from me, don’t ... can you just, OK?