Science Talk November 22, 2006 -- Viruses and Other Organisms Help Create Nanoelectronics; Update on Some Turkey Science
Welcome to Science Talk, the weekly podcast of Scientific American for the seven days starting November 22nd. I am Steve Mirsky. This week on the podcast, we will talk turkey for Thanksgiving with turkey expert Richard Buchholz from the University of Mississippi, and we will test your knowledge about some Thanksgiving science. First up though, the "SA 50," an annual feature of Scientific American. Here's editor in chief John Rennie to briefly explain the "SA 50."
John: It's our annual list, compiled by the editors, of 50 people and organizations that are helping technology to develop for the benefit of society. This is the fifth year for the Scientific American 50 list.
Steve: Fifty people and organizations and so, it's not all scientists.
John: No. That's right. We are trying to take people and organizations from the world of research, but also from business and policymaking, because one of the messages we try to convey with the list is that the development of technology doesn't just depend on bright people in laboratories coming up with new technologies, it also depends a lot on the decisions that businesses make and the ways that they are commercializing them and also the kinds of policy decisions that are made, affecting loss and so forth, that
how these technologies will allow.
Steve: And how are the 50 chosen?
John: They are selected by the editors of the magazine from nominations that come both from the editors themselves,
but[and] from a various outside observers and also including some past winners.
Steve: And the research leader of the year is Angela Belcher from M.I.T. She is still a young scientist. She got her undergraduate degree only 15 years ago, and she has already compiled quite a career. In 2004 she got a MacArthur Fellowship, often referred to as a genius grant. Scientific American cited her for the use of custom-evolved viruses to advance nanotechnology. To find out more, I called her at her office at M.I.T.
Steve: Dr. Belcher, good to talk to you today.
Belcher: Oh, thanks for having me.
Steve: My pleasure. So, you take advantage of natural systems' kind of innate talents to self replicate and self organize and then you get them to do something useful for us. Is that basically a good summary of what your approach is?
Belcher: Yes, we look at how nature makes materials, particularly hard materials —examples are
like shells and bones—and try to understand how organisms through evolution have been able to have such exquisite control over inorganic systems in a way that's environmentally friendly, in a way that is room temperature and room pressure, but with an amazing amount of control at the nano scale to the macro scale. And looking at systems like that, it's just inspiring to us and we say, well, life had a chance to work with certain materials—shells and bones and some magnetic materials—but really hasn't worked with a lot of materials that we would like to use ourselves that we consider more technologically important materials So, in my lab at M.I.T. we give organisms [the] opportunity to work with those materials and try to use them to build devices in a more environmentally friendly way.
Steve: Okay, let's talk about some specifics. I know you are working with viruses. Give me the lowdown.
Belcher: Okay, so we work with a particular kind of virus called M13 bacteriophage. A phage means bacteria eater and so they were very specific hosts, which is a very specific bacteria, and we like these viruses a lot because they only have a couple different genes and those genes code for a couple different proteins and so they are easy for us to manipulate in the lab. And what we do is, through kind of a combination, directed evolution and selection, kind of a Darwinian process, we force these viruses or encourage these viruses to work with materials that we are interested in – semiconductor materials and metal oxide materials for electrodes. In about a couple of weeks period, we can get them to start using precursors to semiconductors and metals and magnetic materials as a basis to control devices.
Steve: Because within a couple of weeks you have lots and lots of generations of these viruses, right?
Belcher: That's right. So, we use what's called the combinatorial approach.
and Organisms had about 50 million years to get good at making hard materials in the ocean based on, you know, trial and error and using what's in their environment, and we don't have 50 million years. We have a short time period, and so we do about a billion experiments at a time, where we can genetically engineer our viruses to express different random peptide sequences and we can, you know, [in] about a one microliter sample we can introduce about a billion different viruses to a semiconductor wafer or an electrode and have them see if they can actually molecularly imprint it or try to do a chemical and physical map to it so that they can actually then have a template to grow that material.
Steve: Because these things have been spending billions of years figuring out the chemistry,
so why reinvent the wheel when the wheel has been perfected?
Belcher: We are just inspired by how when two abalone get together, a male abalone and a female abalone, they make millions of baby abalone, but all have the genetic code that says this is how to build an exquisite shell of the nano structure. So, [what] we want do is, we want to give a solar cell or a battery or an ultracapacitor the genetic information that says this is how to build this device. And once you have the DNA that tells you how to build that device, all you have to do is keep amplifying it and basically passing it on to your offspring, which say this is how to build a solar cell or this is how to build a battery, and that's what is the main driving force in our labs.
Steve: It really sounds like science fiction. People must tell you that all the time.
Belcher: People do tell us that and did tell us that more in the past. But, you know, it seems like a big job but it's really not, because through just [the] selection processes, you and I learned how to make bones using proteins and so we are using the exact same materials—amino acids and proteins—but we are just giving them different starting materials – that of building bones. Let's say, you know, build [with] Cobalt oxide instead and the pieces were all there. It's just when organisms were evolving, they didn't have the opportunity to work with those elements. So, we just think about expanding their horizons and giving them greater opportunity.
Steve: This is the hackney, generous question, but how long do you think it's going to be before you see actual commercial applications for some of these things?
Belcher: I think that it depends on what the commercial applications are. So, some of our battery electrodes were getting pretty good at making those or starting to make prototypes in the lab, and what the final product is – whether it actually has a virus in it or whether it has proteins or amino acids that are used to grow those kind of electrodes– you know, that's really not determined yet. But some of the products in these... the ones that are based more on proteins, I could see, you know, within five years.
Steve: I know you are also looking at yeast and maybe some other organisms. What's next in your lab?
Belcher: Well, our lab right now is really focused on energy and materials for energy. It's an area that we think that we can make a big impact in. One other thing
is that it is exciting to us – it's something that we call nanoalloying, which is basically, how do you put two different materials that are normally hard to grow together side by side? That's something that biology is really good at doing because the template we have to grow these materials, it's a soft template, it's a flexible template, it's a biological molecule.
Steve: What are we talking about specifically in real biological systems?
Belcher: So, this is still... you could do this with yeast, you could do this with bacteria, you could use this with proteins to build these. If you take an example of again, an abalone shell, certain kinds of shells, they put two different crystal structures of calcium carbonate side by side naturally. And so what we are trying to do is put two different semiconductors side by side, or put a metal and a metal oxide side by side. This is for catalytic activities. Tthis is for a fuel cell project. It's for a solar cell project. But it's also for some [of] our medical applications that we are working on – for diagnostic materials, for cancer diagnostics for example. And so we think that's something that biology really has to offer – the ability to grow materials in new ways and place them side by side to make totally new materials, new alloy materials, for all these kind of applications. And so based on that, getting back to the question, we are going to focus on making new kinds of materials and new kinds of alloys and assembling them mostly for energy, but also for medicine.
Steve: And again, this would be a kind of thing that if you were going to use a traditional manufacturing process, [it] would be virtually impossible to get these materials to organize next to each other.
Belcher: Yes, normally to do it would be a very expensive process. We would actually have to lay our materials on top of each other, and the problem is that sometimes two materials you want to put together, they are crystal structures – the way their atoms are arranged and aligned are different. So, when you superimpose them on top of each other, they have to make a lattice mismatch and that causes straying. But if you think about layering materials with a biological template in between it, we are asking the biological template to take on the structure of the atoms of the inorganic materials, and so that relieves the strain and allows you to put things together in new ways.
Steve: Really interesting. So, in 2004 you got a MacArthur Fellowship and these are often called in the popular press genius grants. So, how does that change your life when you have been officially dubbed, in the public's eye, a genius?
Belcher: Well, it is
what [about] expectations I think, which is good that these expectations [are] to be doing very innovative and exciting work, and that's exactly where we want to be and so that part is good. It also brings more attention to the kinds of processes that we are working on, which we are excited about, which is trying to think how to do greener chemistries and environmentally friendly synthesis and organization of materials, and it gives us the opportunity to interact with your scientific interest community that may not be in a particular field that we are interested in, and that's great because there is a lot of interest in biology and biology/nano interfaces and interfaces with the environment and energy right now, and we see a lot of interest from elementary and high-school students as well as people in the community. And so, I think it has raised that awareness, which makes it more fun for us and makes it more rewarding.
Steve: Great stuff Dr. Belcher. Thanks very much. I appreciate your time.
Belcher: Thank you very much.
Steve: The entire SA 50 list is in the December issue of Scientific American and is available on the Web site, www.sciam.com.
Now it's time to play TOTALL.......Y BOGUS. Here are four science stories. Only three are true. See if you know which story is TOTALL.......Y BOGUS.
Story number 1: You can buy a robotic turkey to help you flush out poachers.
Story number 2: Cooking fires are twice as common on Thanksgiving than on a typical day.
Story number 3: I live in the Bronx in New York City and I have never once seen wild turkeys wandering around within the city limits, not a trick question, I am not counting the Bronx Zoo.
Story number 4: This year's crop of turkeys are a little bit smaller on average than your typical turkey.
We will be back with the answer, but first, Americans will eat about 45 million turkeys on Thanksgiving. That's about a sixth of the entire year's turkey consumption. Ten years ago, I spoke to turkey researcher Richard Buchholz, who was doing some fascinating work that I wrote about in the September 1996 Scientific American. The male turkey's bald head had been thought to serve as a signal to females that the guy was available, but Buchholz thought the bald head might also help the turkeys dump body heat. His experiments, which involved, no kidding, putting socks on the turkey heads, showed that if turkey heads were feathered, the birds will indeed struggle in hotter parts of the country. Anyway, I thought for Thanksgiving I would check in with Buchholz and get the latest turkey tales. I called him at his office at the University of Mississippi.
Steve: Dr. Buchholz, great to talk to you today.
Buchholz: Nice to talk to you Steve.
Steve: So, you are, correct me if I am wrong, a full-time professional turkey scientist. Is that right?
Buchholz: I am a full-time animal behaviorist who focuses on the behavior of turkeys.
Steve: The behavior of turkeys. So are the turkeys behaving?
Buchholz: They are behaving. They are a little nervous this time of year, but they are behaving.
Steve: Well, that's certainly understandable. So, tell me about your current turkey research.
Buchholz: Well, a long-term interest of mine has been whether the ornaments that are sexually selected in turkeys that are involved in mate assessment indicate something to female turkeys that might help them raise more offspring, and specifically the idea that those ornaments are dependent on the parasite load of the male that has them. So, that is, a female who chooses the male with larger, brighter ornaments can be assured that that male grew to look prettier to her because he has fewer parasites and she is unlikely to get these parasites during mating. So, it's not an issue of her possibly becoming infected by these parasites, but because there is usually a genetic basis [for] parasite resistance, she may be looking for good genes for her offspring to survive better.
Steve: Alright, so that the offspring would have a lower susceptibility toward getting the parasitic load in the first place.
Buchholz: Right, yeah. I mean, male turkeys don't provide any paternal care. They don't help the female incubate the eggs. They don't feed her. They don't protect their young. So, all she is getting from him
are [is] sperm, so that she has a matching set of genes for her offspring, and she is going to only get that from a male. She should choose carefully and parasites are an important part of turkey life history. So, finding a resistant male and getting his resistance gene to her offspring is probably evolutionarily a good idea.
Steve: Right, and she doesn't realize that's what she is doing. She has just been programmed to be most attracted to the turkeys that have the brightest colors, and those brightest colors are maker for the health of the turkey.
Buchholz: Well, usually in animal behavior studies we don't make any assumptions about the individual animal thought processes per se.
Steve: Good idea.
Buchholz: So, turkeys don't have a good reputation for being smart. I would say, they have been around for a very long time, so they are smarter being wild turkeys, but yeah, she doesn't necessarily have to walk around and say, oh, by mating with this guy I am going to have more surviving offspring. All that has to happen is the genes that make her be choosier about this have to survive better till the next generation by showing up in babies that survive better because their resistance is perfect.
Steve: So, I saw on your Web site some research related to the ultraviolet reflection of the feathers. What's that all about?
Buchholz: Well, it turns out that turkeys can see wavelengths of light that we can't see, and those are wavelengths in the ultraviolet spectrum. So, we normally think about ultraviolet as harmful; that it causes melanoma, skin cancer, and that sort of thing. But the near ultraviolet is actually used by some organisms, some birds, lots of insects, and it turns out that turkeys are one of the bird species that can see the ultraviolet light. So, I was curious about whether turkeys could see changes in feather reflections – the colors coming off the feathers when they are parasitized that we can't notice. And by collaborating with colleagues at Auburn University, we are able to show that the turkeys that I experimentally infected with parasites actually showed less UV reflections from their shiny feathers on their breasts and their wings compared to turkeys that had never been infected.
Steve: Well, so, a parasitized turkey looks completely different to another turkey than a non-parasitized one and in ways that we can't really appreciate.
Buchholz: Exactly, yeah. So, because we can't sense ultraviolet light with our visual pigments, we can't even pick up on the cues that turkeys are probably using, and now that I know that this is changing, the next step is to find out whether females actually care about this change, which we don't know whether there is a behavioral response to turkeys being different in their ultraviolet reflections. We do know that domestic turkeys prefer to be in poultry houses where the lighting includes the ultraviolet wavelength.
Steve: Interesting, because without the UV they keep looking around saying nothing looks right to me.
Buchholz: That's right. Imagine the UV as another color in the spectrum. What it looks like, how turkeys perceive it, we don't know, but that's sort of equivalent of beyond ultraviolet, a whole other sort of color.
Steve: So, it's like if we were in a dark room where we just could not make out certain colors.
Steve: Interesting, Dr. Buchholz, very interesting. Thanks very much.
Buchholz: Thank you, Steve.
Steve: For more turkey research news just google Richard Buchholz, and there is more from Richard about the turkey on your table over at today's edition of the daily Scientific American podcast, 60-Second Science, that's available at the Web site and at iTunes.
Now it's time to see which story was TOTALL.......Y BOGUS. Let's review the four stories.
Story number 1: Robot turkeys help pinch poachers.
Story number 2: Kitchen fires double on Thanksgiving.
Story number 3: I have never seen wild turkeys spread their stuff in the Bronx.
Story number 4: 2006 turkeys are slightly smaller than normal.
Story number 1 is true. A company called Custom Robotic Wildlife, Inc. sells robot turkeys designed to entice would-be poachers. The $1,100 dollar robot turkeys can fan their tails and bob their heads and keep doing that even after catching a shotgun blast, although after it's hit you probably want to put on a new turkey skin and wait for it. Dressing sold separately.
Story number 2 is true. Thanksgiving sees twice as many cooking fires as a typical day. That's according to statistics from the U.S. Fire Administration. Last Thanksgiving, about 1,450 reported cooking fires were responsible for some $21 million dollars of property damage. That's why I leave it to the professionals and eat out.
Story number 4 is true. A hot summer in your prime turkey farm areas resulted in birds that are slightly smaller than normal.
All of which means that story number 3 about me never seeing wild turkeys within the New York City limits is TOTALL.......Y BOGUS, because wild turkeys are doing quite well in the Bronx, thank you. You'll often see them crossing the road in the northeast part of the Bronx, which still has a lot of forests. Why did the turkey cross the road you ask? Hey, who wants to know? What are you doing sticking your beak into that turkey business? Remember, this is the Bronx. What happens here stays here. In fact, you didn't even see what happened here, my friend. So, why don't you just move along, go home, have yourself a nice Thanksgiving dinner with your family. Anybody asks you what you have seen, you just ask them to pass the potatoes.
Well that's it for this Thanksgiving edition of the weekly Scientific American podcast. You can write to us at firstname.lastname@example.org. Check out news articles and science video news at our Web site, www.sciam.com and the daily SciAm podcast, 60-Second Science, is at the Web site and at iTunes. For Science Talk, the weekly podcast of Scientific American, I am Steve Mirsky. Thanks for clicking on us.