What Happens When Scientists Get It Wrong?

Reporting in Science, two teams of scientists say they were unable to replicate the results of a 2010 study claiming to have found 'alien life' on Earth—a bacterium that could build its DNA using arsenic. Science journalist Carl Zimmer talks about how the controversy played out online, and how science corrects itself.

Copyright © 2012 NPR. For personal, noncommercial use only. See Terms of Use. For other uses, prior permission required.

IRA FLATOW, HOST:

This is SCIENCE FRIDAY; I'm Ira Flatow. A couple of years ago, we interviewed a young scientist about a type of alien life she'd discovered right here on Earth, a strain of bacteria that could build its DNA with arsenic rather than phosphorus, something no other known creature is able to do.

There were NASA press conferences celebrating the discovery. There were TED talks. There were plenty of gushing news articles. But quite a few scientists who saw the paper were skeptical of the findings, saying the research was flawed. But this is research, right? So to disprove something, you have to try to replicate the study, research it, that's why it's called research, to see if you get the same results or not.

Well, two studies out this week in the journal Science did just that, and they could not replicate the original group's finding. They concluded that this bacterium does not break the rules of life as we know it; it's just like all the rest of us.

So case closed or not? My next guest has been following this debate since the very beginning. Carl Zimmer is the author of "A Planet of Viruses." He's a contributor to The New York Times and Slate and a contributing editor at Discover, and he joins us from WSUI in Iowa City. Welcome back to SCIENCE FRIDAY, Carl.

CARL ZIMMER: Hi, thanks for having me.

FLATOW: This shows us what about science?

ZIMMER: This shows us that science is something that's done by people, people who are not perfect. And if you want to understand how science works, you have to understand it as kind of a cultural process. It's a story about excitement, about hype, about debates and about ultimately how science can correct itself if you give it enough time.

FLATOW: But the original authors have stuck to their research, have they not?

ZIMMER: Yes, so the original authors have been interviewed by reporters at the Washington Post and other places, and they're saying that, you know, there's nothing in the data that actually undermines what they were - undermining their own conclusions.

So - and they've made some suggestions, which frankly I don't quite understand. They, for example, have suggested that somehow during the transportation of these bacteria to these other labs, they changed somehow so they could no longer accommodate arsenic in their DNA.

Now, how it could be that two labs would both fail to get the same result after the stuff was transported raises some serious questions about that kind of an objection. But as you say, yeah, they're sticking by their guns.

FLATOW: It sounds a little bit like I remember cold fusion from those days.

ZIMMER: That subject has come up in some conversations I've had. Yeah, I mean, the people who claimed cold fusion was taking place, these two physicists, they did not back down long after the physics community, you know, decided that what they had found was not legitimate.

FLATOW: Does science really work the way we think it does? Is it realistic to expect scientists to drop everything they're doing to replicate a study that they don't like or suspect is not working?

ZIMMER: Well, you know, that is, in theory, what makes science is really powerful is that we don't have to just rely on someone's authority. If someone says hey, I'm a big-shot scientist, you have to believe what I say, you don't have to accept that. You can question their results, and you can try to replicate them and see if you can do it yourself.

And the scientific community can evaluate big ideas. Carl Sagan really put it quite elegantly, as he often does. He said there are many hypotheses in science which are wrong. That's perfectly all right. And the reason was because science is a self-correcting process.

But as you say, it's harder in practice than it is in theory because, you know, it does take a lot of time. And, you know, a lot of people who looked at this arsenic life paper who I spoke to when I was reporting on this, they just, they read the paper, and they could see serious problems with it just looking at the paper itself. And so they were quite confident that it was wrong.

And so a lot of them just said, well, I have better things to do with my time.

FLATOW: Yeah, 1-800-989-8255. And of course if you're a scientist, and you decide to re-research, to redo that experiment, and it comes up negative, journals really don't want to publish things that don't show positive results, do they?

ZIMMER: There is an unfortunate tendency for journals to go for, you know, big, flashy new results. And, you know, they may justify it in various ways, but I don't see how that advances science. If self-correction is so important for science, then there should be a place for these kinds of studies.

I think one of the most amazing examples happened actually last year. There was a psychologist named Daryl Bern, who published a paper in the Journal of Personality and Social Psychology, where he claimed that events in the future could affect people's minds in experiments he was doing, essentially like concluding that there was such a thing as ESP or clairvoyance.

And there were three groups of scientists who tried to replicate those findings. They all failed. And one of them submitted their results to this journal, and they rejected it, and they said that they have a longstanding policy of not publishing replication studies, and that was it.

So, you know, it seems like the way science is done is not living up to how science should operate.

FLATOW: One thing you've also talked about and written about is how TED talks can sometimes present bad science without being skeptical enough because they're eager to get speakers with flashy new findings.

ZIMMER: Well, I think that we have - there's a general impulse to eagerly grab onto the next big thing. So Felisa Wolfe-Simon, for example, did give a TED talk several months after publishing this paper, and - but she was also named one of the Time 100 of the Year for 2011. And so, you know, there's this attraction to the new that oh, you know, this is going to change everything.

And I think actually that we all need to kind of resist that because something that seems incredibly appealing might turn out to be wrong, and we should give things some time to let science work.

FLATOW: Felisa Wolfe-Simon was the person who published the arsenic paper originally, just...

ZIMMER: She was the lead author on the study, yes.

FLATOW: She was also profiled in Glamour magazine as a role model for young women scientists.

ZIMMER: She was, she was. I mean, I think part of the controversy that got engendered by this whole story was that the scientists were quite happy to have a very high-profile press conference to announce these results after several days of people wondering if NASA had actually found aliens.

But - and they made a lot of big claims about, you know, essentially that this was going to change textbooks, change our conception of life and so on. And then some reporters like myself said, you know, actually there are some critics out there who think that this is not a good paper, and they didn't want to talk, and they immediately said oh, well, we can only do this through peer-reviewed channels.

And that struck some people as being a little odd, that suddenly when things weren't going their way, they didn't want to talk.

FLATOW: That's another Saganism, you know, extraordinary claims requires extraordinary evidence.

ZIMMER: Absolutely.

FLATOW: Yeah, here's a tweet from Yarton(ph), who says: Are the scientists who dismissed this out of hand just caught in their own mindsets, seeing that they've been trained to see, seeing what they've been trained to see?

ZIMMER: Well, the problems that they were pointing out were often problems with the method. So for example, they were saying that the original authors hadn't done enough to rule out much less exotic possibilities. So for example, when they claimed that there was arsenic in their DNA, which really would be quite radical if DNA was made up of arsenic, these critics said, you know, you haven't eliminated the possibility that maybe the arsenic that you're trying to feed these bacteria is just contaminating your sample of DNA.

And so actually when these studies were replicated, the scientists who were replicating it actually were very careful to wash the DNA, and lo and behold, once you wash the DNA, you don't find arsenic. So that would tend to support the idea that the arsenic was just contamination.

FLATOW: Jamie(ph) in Washington, D.C., hi, welcome to SCIENCE FRIDAY.

JAMIE: Hi, Ira, thanks for taking my call. Carl, I just wanted to ask you about the review process by which this process got into Science. And also the - you know, NASA had the big press release associated with this paper. If there are scientists out there who were so quick to dismiss the data, why didn't the reviewers at Science and the scientists at NASA catch it, as well? I mean, were they caught up in the hype?

ZIMMER: Well that's a good question. You know, the peer review process at a journal like Science is kept private. So we don't know who they asked to review this paper. We just don't. And I would love to know. But just judging from what the scientists I've talked to have said, clearly the reviews just weren't careful enough, or they didn't consider these possibilities, which seemed pretty obvious to the critics.

And so, you know, this raises a question about whether papers that are very exciting and very flashy, maybe sometimes they get pushed too quickly through the peer review process. Maybe they need to be looked at more carefully, and, you know, journalists should resist that allure that they're going to get big headlines and big press conferences if they just get that paper out.

FLATOW: Right, Jamie? Thanks for calling. Of course now in the blogosphere and, you know, the Internet and tweeting and instant news 25 hours a day, it's a lot more difficult than in the old days of 10 years ago when there was more time to think about it and publish it and...

ZIMMER: That's true. But on the other hand, you know, blogging can serve a good purpose...

FLATOW: Yeah.

ZIMMER: ...where people can raise these issues. I mean, I first became aware of some of these issues through a blog. One of the critics was Rosie Redfield, and she - she's a microbiologist at University of British Columbia. She has a blog basically where she just writes to think out loud. It didn't get a whole lot of traffic, but I visited sometimes. And she wrote a very long piece right after the paper came out, saying - explaining why she didn't think the paper was good. And, you know, so she was airing what a lot of people were thinking.

FLATOW: Yeah. Is this kind of controversy going to discredit this field of science, of looking for other types of life, do you think?

ZIMMER: I think that's a big concern that a lot of scientists have in this area. I mean, the fact is that there's a lot of research in this area, and it's an interesting question. You know, the fact that all life on Earth has got DNA and RNA, does that mean that those are the only molecules that can handle the job of life? That's an open question.

And so there were some, you know, ideas that you could come up with, with how maybe arsenic could create a new - you know, be part of a new molecule that would act like DNA, switching arsenic for phosphorus. That's, you know, a hypothesis you can investigate if you want.

And there are other people who are looking at other kinds of weird molecules that might act like DNA. Maybe you can invent them in your lab, or maybe they exist on other planets, or maybe they are somewhere here on Earth. So it would be too bad if the baby got thrown out with the bath water.

FLATOW: Yeah. You're someone who writes and talks a lot about viruses, so you're certainly interested in new kinds of life.

ZIMMER: Sure, yeah. And, you know, just doing - just people studying viruses have, in just the past couple of years, found some really bizarre things that break a lot of the rules about how we thought life works. And so, you know, we know that there's a lot of weird life here on Earth, let alone on other planets.

FLATOW: Great quote for a tweet today, talking with Carl Zimmer on SCIENCE FRIDAY from NPR. A lot of - tell us a little bit more about some more weird life here on Earth that would match anything in the - what's the weirdest form of life - I know you study viruses - that would match anything that you could find if - on Earth, in outer space? What's your favorite?

ZIMMER: One thing that I'm kind of fascinated by are these things called giant viruses, which are so big that they were mistaken for bacteria. They're about 100 to 1,000 times bigger than your average virus. And so they were just hiding in plain sight, just in front of everybody. And it turns out giant viruses are everywhere, and they're totally bizarre as viruses go.

What happens when they invade a host cell, they don't kind of break up and just, you know, their genes get replicated. They sit there, almost like a cell, and they bring in nutrients and then produce new viruses that get spit out of this, what's called a virus factory. These viruses are so weird that they actually get their own viruses, which are called virophages. So they're actually viruses of viruses.

And again, nobody knew about these until just a few years ago, and now they're finding them everywhere. They're finding them, you know, two miles below the ice at Antarctica, for example. So there's probably a lot of really bizarre life on Earth.

And who knows? You know, maybe, you know, in some extreme environment, we are indeed going to find life that breaks the rules about, you know, what's life - what life is made of. But it doesn't seem like we've found it yet.

FLATOW: Mm-hmm. Because that's what they always talk about, that, you know, maybe we're not a carbon-based life out - some other life form that's not carbon-based, but, what, silicon-based, something like that.

ZIMMER: Yeah. Some "Star Trek" fans may remember that episode where there was this - I think it was called the Horta, there was this silicon-based alien. Well, actually, you know, the National Research Council brought together a group of scientists to think about all the different possibilities of how life could exist. And they actually did talk about silicon-based life, you know? And they sort of gave a tip to the Horta there because, you know, silicon has some chemical properties that might maybe be able to...

FLATOW: Yeah.

ZIMMER: ...encode genes. It's possible. And so these are really provocative ideas that are leading people to do, you know, experiments. For example, they're dealing with molecules sometimes called XNA, which is something that's like DNA, but has a different composition. And they're actually, they're making these XNA molecules evolve in the lab. So, you know, it's not quite life, but it's getting really interesting.

FLATOW: Wow.

ZIMMER: And there are even, like, good possible spinoffs in terms of biotechnology for these things. You know, you can evolve these molecules, and they can do interesting things for you. So, you know, someday we may be using these alien molecules in our medicine.

FLATOW: If, you know, we send probes - and there's one headed to Mars now, another rover headed to land there - to look for signs of former life. Should we be looking for signs of former viral life, not just microbial, bacterial life?

ZIMMER: I think that it would be kind of hard to look for signs of viral, you know, ancient viral life. I mean, viruses don't fossilize. They're so tiny, and they don't really leave a mark. I mean, bacteria actually do leave microscopic traces, or they can even create things that are visible to the naked eye; fossil formations, kind of reef-like structures. So that might be something to look for on Mars, you know, but, you know, but if there is - if there are microbes on Mars, then they probably have viruses because...

(LAUGHTER)

ZIMMER: ...it's such a great way of making a living that, you know, it's just - they would be there, I would predict. And...

FLATOW: All right. We'll see what happens. Carl Zimmer, always fascinating to have you on. He is author of "A Planet of Viruses." He's a contributor to The New York Times and Slate and a contributing editor at Discover. Thanks, Carl. You'll come back, OK?

ZIMMER: OK. Thanks a lot.

FLATOW: You're welcome. We're going to take a break. And when we come back, we're going to talk about hydrating. You love that word hydrating yourself from the heat? We'll talk about the best way to do it. Stay with us. I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.

Copyright © 2012 NPR. All rights reserved. No quotes from the materials contained herein may be used in any media without attribution to NPR. This transcript is provided for personal, noncommercial use only, pursuant to our Terms of Use. Any other use requires NPR's prior permission. Visit our permissions page for further information.

NPR transcripts are created on a rush deadline by a contractor for NPR, and accuracy and availability may vary. This text may not be in its final form and may be updated or revised in the future. Please be aware that the authoritative record of NPR's programming is the audio.

Related NPR Stories

Comments

 

Please keep your community civil. All comments must follow the NPR.org Community rules and terms of use, and will be moderated prior to posting. NPR reserves the right to use the comments we receive, in whole or in part, and to use the commenter's name and location, in any medium. See also the Terms of Use, Privacy Policy and Community FAQ.