Water bears, aka tardigrades, can withstand boiling, freezing and the vacuum of space. Biologist Bob Goldstein, of University of North Carolina, Chapel Hill, studies these millimeter-long creatures to try to understand how organisms develop.
IRA FLATOW, HOST: Up next, Flora is here with our Video Pick of the Week. Flora, what have you got for us today?</s>FLORA LICHTMAN, BYLINE: Today, we have - the astonishing creature hour continues with our Video Pick.</s>FLORA LICHTMAN, BYLINE: Let me introduce you - if you haven't heard of this creature already - to the water bear, aka, the tardigrade. These little one millimeter long creatures, they - they're called water bears because they look like teeny, tiny, puffy little bears, but with eight legs. They're adorable, if I may editorialize, which - always. And their special claim to fame is that they can survive almost anything, it seems. So let me just give you some specific examples. You can boil a tardigrade, and it will live to tell the tale. You can put it down to below one degree Kelvin. Now, zero degrees Kelvin is where molecular motion stops, so...</s>IRA FLATOW, HOST: One degree Kelvin.</s>FLORA LICHTMAN, BYLINE: ...and it will survive. You can dry it out for years and not feed it. It will come back to life. It can live in the deepest parts of the ocean. It can survive the vacuum of space. These guys are crazy. I don't know else to put it. They're amazing.</s>IRA FLATOW, HOST: Wow. So where do we find them?</s>FLORA LICHTMAN, BYLINE: On our website, sciencefriday.com</s>IRA FLATOW, HOST: Exactly. They're our Video Pick of the Week. Flora Lichtman's got them up on our website as our Video Pick of the Week. And what do we see? What are they doing - you uncovered all these secrets on this video.</s>FLORA LICHTMAN, BYLINE: They were crawling around a Petri dish.</s>IRA FLATOW, HOST: Yeah.</s>FLORA LICHTMAN, BYLINE: But you see them through the microscope. They're probably in your backyard, too. So they live in all of these extreme environments where they can live in these extreme environments. But they also are in, like, every puddle.</s>IRA FLATOW, HOST: Right.</s>FLORA LICHTMAN, BYLINE: Or - I don't know every puddle. They're common.</s>IRA FLATOW, HOST: Right. Right. Right. Their in nature, and they have learned how to survive just about anything.</s>FLORA LICHTMAN, BYLINE: Right. So this is why researchers are - one of the reasons why researchers like Bob Goldstein at the University of North Carolina at Chapel Hill is interested in them. He studies how organisms develop. And one of the things that he's been looking at is how did these organisms develop, and what genes control their ability to survive in all of these different places?</s>IRA FLATOW, HOST: Right. Right.</s>FLORA LICHTMAN, BYLINE: And so he's - you know, we actually talked to him years ago for this video. But I checked in with him this week on what's new. And they're actually working on sequencing the water bear genome. So stay tuned for part two. I can't wait...</s>IRA FLATOW, HOST: Wow. Wow.</s>FLORA LICHTMAN, BYLINE: ...to figure out - you know, to try to unravel what genes are responsible for these amazing abilities to survive.</s>IRA FLATOW, HOST: You know, no wonder they sterilize those Martian landers when they send them. Imagine if some water bears, I mean...</s>FLORA LICHTMAN, BYLINE: They get populating more, then...</s>IRA FLATOW, HOST: They can survive just about anything.</s>FLORA LICHTMAN, BYLINE: They can survive radiation, too. So I think that's an apt point.</s>IRA FLATOW, HOST: And it's our Video Pick of the Week. It's up on our website at sciencefriday.com, along with all of our other great Flora videos up there.</s>FLORA LICHTMAN, BYLINE: Can I add one more fun fact about these guys?</s>IRA FLATOW, HOST: Sure. Please.</s>FLORA LICHTMAN, BYLINE: They're in their own phylum, too. So you might be thinking, you know, what are these guys related too? Nothing.</s>FLORA LICHTMAN, BYLINE: We're in a phylum with sea slugs, so - sea squirts. So, you know...</s>IRA FLATOW, HOST: But these water bears are...</s>FLORA LICHTMAN, BYLINE: They're their own branch.</s>IRA FLATOW, HOST: Well, I would imagine that if you can survive all that stuff, right, and you can be zapped with radiation, frozen to almost to almost absolute zero, you can dry up or you go into some sort of...</s>FLORA LICHTMAN, BYLINE: It's called the tun phase. They sort of shrivel up, became desiccated, and then they can just survive all of these things, and then be brought back to life.</s>IRA FLATOW, HOST: And they just wait for the right moment to...</s>FLORA LICHTMAN, BYLINE: You just - a drop of water, I think, will do it.</s>IRA FLATOW, HOST: A drop of water, and if you want to learn all about that, go to our website at sciencefriday.com and see these water bears. What's their full name again? The...</s>FLORA LICHTMAN, BYLINE: The tardigrades.</s>IRA FLATOW, HOST: Tardigrade.</s>FLORA LICHTMAN, BYLINE: Some people also call them moss piglets. I think our listeners already know about them. And so if you're a water bear enthusiast, also leave us a comment with your water bear tale. I think there's no shortage of amazing stories about these guys. So I'm sure we missed some.</s>IRA FLATOW, HOST: That's right. Good idea. Go to our website and watch the video, and then leave a comment. Maybe you had your own experience with them.</s>FLORA LICHTMAN, BYLINE: Yup.</s>IRA FLATOW, HOST: And also, while you're there, you can surf over and read all the other good stuff we have there. Thank you, Flora.</s>FLORA LICHTMAN, BYLINE: Thank you, Ira.</s>IRA FLATOW, HOST: Flora Lichtman with our Pick of the Week. Also, just a quick reminder that make sure you got out and see Comet PANSTARRS this weekend, around - it's around sunset. It's going to be shown up. It is supposed to be spectacular. It was up on the Southern Hemisphere, and they had great sightings of it. Now, you should be able to see in around sunset here in the Northern Hemisphere.