Ex NASA Astrobiology Instit. Chief Bruce Runnegar

I’ve been having bits and pieces of communication with former NASA Astrobiology Institute chief Bruce Runnegar in recent weeks in between his field trips to Australia — sometimes via his wife Maria, a biochemist at the University of Southern California. Runnegar …


Ex NASA Astrobiology Instit. Chief Bruce Runnegar

By SUZAN MAZUR


Bruce Runnegar, Astrobiologist & former Director, NASA Astrobiology Institute

I’ve been having bits and pieces of communication with former NASA Astrobiology Institute chief Bruce Runnegar in recent weeks in between his field trips to Australia — sometimes via his wife Maria, a biochemist at the University of Southern California. Runnegar is investigating the oldest complex fossils — Ediacara fauna, there as well as in Namibia, South Africa and Newfoundland. He speaks with a quiet ease and told me during my phone call to him last week at the University of California, Los Angeles, where he is a professor of paleontology, that he’s “firmly disconnected from NASA for the last two years.” But I was interested in how NAI’s virtual organization works, so he agreed to explain. Runnegar is as comfortable discussing that as he is “the kerfluffle about the French Impressionists” on the Victorian scene, and defending natural selection in business (our chat was prior to the Dow falling 700 points).

Although no longer NAI chief, Bruce Runnegar still considers himself an astrobiologist. His interest is in events that coincided with the Cambrian explosion of multicellular organisms a half billion years ago. And while he recognizes self-organization as a mechanism of evolution, he doesn’t buy the idea of plasticity in Cambrian multicellular organisms. Said Runnegar: “There was a common ancestor which didn’t resemble anything that we see in the Cambrian.”

Runnegar also challenges fellow native Australian astrobiologist Roger Buick’s analysis that the 3.47 billion-year-old rock at Australia’s North Pole holds the oldest evidence for a specific metabolic process carried out by life — sulfur-eating bacteria. Runnegar’s got a year of sabbatical and plans to publish his results by December demonstrating that Buick’s findings are not correct, that the sulfate deposits Buick found were due to exposure to hydothermal fluids, not bacteria.

Bruce Runnegar served as the third director of the NASA Astrobiology Institute, beginning his tenure at Ames Research Center in September 2003. He was director of UCLA’s Institute of Geophysics and Planetary Physics for five years prior to that.

Dr. Runnegar has a D.Sc. and Ph.D. from the University of Queensland, Australia.

Our interview follows.

Suzan Mazur: The NASA Astrobiology Institute established 10 years ago has been described by Astrobiology magazine — not the Astrobiology journal with links to NASA – as follows:

“a virtual organization composed of NASA field centers, universities and research organizations that collaborate to study the origin of evolution, distribution and future of life in the universe. Astronomers, biologists, chemists, geologists, paleontologists, physicists and planetary scientists are involved with teams chosen via peer-reviewed proposals.”

You were the director of the NAI a few years ago – roughly how many people are involved in NAI, and what would you say was your most important achievement as director?

Bruce Runnegar: Astrobiology is not a NASA journal or a NASA-influenced journal. It’s a journal like any other journal in the community. It’s run by an organization which is interested in making money.

The leader of that organization has chosen astrobiology as a developing field. Her business model is to find new fields of science and try to develop journals in those areas. There are a lot of NASA-connected connections with it, of course, because a lot of people working in astrobiology work with NASA or are funded by NASA. It’s certainly not a NASA mouthpiece.

Suzan Mazur: You were director of NAI a few years ago?

Bruce Runnegar: Yes.

Suzan Mazur: How many people are involved with NAI and what would you say was your most important achievement as director?

Bruce Runnegar: When you ask how many people are involved, you’ve got to ask how many people are loosely connected. I’m not trying to avoid the question, but one way of looking at it is how many people are paid on a full time basis. And that’s relatively few.

But many people are connected as academics, as advisors of postdocs and graduate students. People fully employed on NASA funding? There are a few hundred students and post docs mainly. Academics get some salary assistance as is the tradition in American universities. NASA center members get more of their salaries from these sorts of sources. So a few hundred people are employed full time.

But there are probably, as you quoted in the article with Roger Buick, in the order of 1,000 people who are somehow connected with the NASA Astrobiology Institute. There are hundreds of institutions that are receiving some funding from the NAI.

There are 15 or 16 teams currently. They are also composed of consortia of other organizations, other universities, other research institutes. So if you total the number of organizations, it’s in the order of hundreds.

My greatest achievement? What I was trying to do was to overcome the inherent difficulty of this kind of organization in that fierce competition to obtain membership through peer-reviewed processes. And then as soon as one is funded – and not just one person but tens of persons per team – then the idea is that these teams must then instantly learn to reverse that thinking and become collaborative and start to share resources, work toward a common good.

So taking the process somewhere down that track is what I was aiming for and regard as the most important achievement. Summarizing that, it’s collaboration after competition.

Suzan Mazur: As former NAI director, can you tell me who makes policy at NAI and decides, for instance, that natural selection is the mechanism of evolution the public should know about?

Bruce Runnegar: No one decides that sort of thing in this organization. This is a scientific research organization. So what the public learns is what is believed to be the state of the art of science. The organization assists with that process trying to educate the public about new discoveries, but these discoveries like all science are subject to community acceptance and understanding.

Science, as you know, goes down the wrong track for many decades – as it did in the Earth Sciences when people didn’t believe in continental drift and plate tectonics. Then eventually it takes a U-turn.

Suzan Mazur: The NAI supported publication Astrobiology Primer. Were you heading NAI at the time this was supported?

Bruce Runnegar: Yes.

Suzan Mazur: The explanation for natural selection being promoted as the sole mechanism of evolution in that publication – the decision about that would have been whose?

Bruce Runnegar: This is not a decision. The people who compiled the Primer are aiming to provide an educational service and so they write or wrote or acquired definitions of words. Basically trying to explain the jargon of astrobiology. Some of these explanations almost anybody could have different opinions about.

There were reviews of the document by scientists connected with the institute [NAI], but I don’t think there’s any attempt to provide a stamp of approval for any particular definition.

Suzan Mazur: I spoke with Lucas Mix, the editor of the Primer, about this. Mix is now writing a book on astrobiology, forthcoming from Harvard University Press. He referred me to the minor mention of neutral selection in the Primer, but natural selection was really the only mechanism of evolution discussed.

Do you think the next edition of the Primer will be updated to include current scientific thinking?

Bruce Runnegar: Natural selection is not a mechanism, it’s the process by which the results of evolution are sorted.

Suzan Mazur: There are mechanisms which are being discussed in a major way, which were not covered in the Astrobiology Primer.

Bruce Runnegar: What do you mean by alternative mechanisms?

Suzan Mazur: Like self-organization for instance.

Bruce Runnegar: That’s what I’m saying. There are lots of mechanisms we know about. Self-organization being one of those kinds of mechanisms. Neutral evolution of genes. In other words, substitution without any change in the expression of the genes as far as we can tell. Those are sorts of mechanisms. But all of those are going on all the time producing a set of organisms which then natural selection acts upon.

You have to have variability in populations or in the biosphere. And that variability is produced by those mechanisms including self-organization. But ultimately it is competition or selection among those members of the biosphere that is the evolutionary process. That was Darwin’s insight. Not the production of variation, but the ultimate effect of pruning by the natural selection process.

I think natural selection operates on all those mechanisms. That’s, I guess, the point.

Suzan Mazur: There is a growing understanding that the peer-review process is rigged to maintain science status quo – that it holds back scientific progress.

Swedish cytogeneticist Antonio Lima-de-Faria calls this the “cycle of submission”. He speaks of censorship in literature, like in the 2002 Encyclopedia of Evolution which left out even A. Muntzing’s work with Galeopsis from the 1930s where Muntzing crossed two different species and by doubling their chromosome number got Galeopsis tetrahit which occurred spontaneously in nature. Lima-de-Faria says no successive random mutations were needed.

In the case of Astrobiology journal’s board there is a significant representation of NASA employees, which David Deamer recently acknowledged in an interview with me.

Do you see this as a problem, is there too much of a status quo operating in the peer review process holding back discovery?

Bruce Runnegar: How is this any different from any other form of human activity? It happens in the arts. It happens in music. You remember the kerfluffle about the French Impressionists when they first came onto the Victorian scene. How dreadful their art was. It’s just human nature to want to maintain the status quo and to keep things on the path one is accustomed to. And it’s no different in science. People don’t like to be shaken up with new discoveries. And new ideas do shake people up. So there is naturally some resistance. And it inevitably shows up in peer-review processes. It’s just part of the way humans work.

Suzan Mazur: Are we any closer to answering the questions about the origin of life 10 years on?

Bruce Runnegar: I think we’re getting a lot of new information that certainly bears on that question both in terms of how life actually works. And that comes from the understanding we’re getting from genomes. Not just the old idea that there is DNA that makes a gene and the gene makes proteins and the proteins all work together. And that all of the processes are much more complicated than people imagine. There are many more loops in the biochemistry of organisms. There are many cases where the RNA itself does the job and feeds back into the protein loop. So this whole system has become so much more complex. We understand the nature of life a lot more than we did 10 years ago. It’s not just astrobiology. This is the advance of science as a whole.

Suzan Mazur: What are your thoughts about the origin of the gene?

Bruce Runnegar: Nearly every gene we see in nearly every organism is a modified copy of another gene that existed previously. A gene can stay more or less intact or evolve to have a new function by changing constituents of the gene, or a piece of a gene can be spliced with a piece of another gene in an evolutionary context.

As to how genes got started in the first place – that’s a more complicated question. But we know from experiments in the last decade that you can actually make RNA that will evolve to do something in a lab in hours to days. So self-organizing of molecules that can do something worthwhile is certainly a very plausible hypothesis.

Suzan Mazur: Is the line between life and non-life arbitrary?

Bruce Runnegar: That’s a more difficult philosophical question. That’s something that we haven’t really got a good idea of yet because we have such a diverse difference with the possible caveat of some viral-like particles. There it becomes rather difficult to separate. But that’s all based on the same biochemical system. A bit like computer viruses are very separate from programs.

It’s kind of a question that doesn’t have any meaning if you don’t have computers and codes in the first place. So it’s all part of the living system and I don’t think the definition matters in that case. With regard to life elsewhere, it’s something we have no experience of, so it’s hard to know whether we’d be more blurred with the inorganic world or not.

Suzan Mazur: Do we arrive at biological life via atomic, chemical, mineral evolutionary footprints?

Bruce Runnegar: That’s what everybody thinks is the most reasonable.

Suzan Mazur: So everything is wired back to the atomic level?

Bruce Runnegar: First you have to build elements and you have to make them in stars. You know the story. Then you have to make compounds out of those elements. And if you go through and suggest what compounds are likely to be involved in life-like processes, you end up with a small short list. Carbon being one of those.

Then some of the fundamental things that we know about life – you don’t want too many strong bonds amongst all these atoms because otherwise you end up with a solid that’s like a piece of rock. You want some strong bonds and a lot of weak bonds.

There are obvious chemical reasons why life should prefer certain sorts of chemistry, etc. Yes, I think there is a hierarchy. Cells are part of that hierarchy, tissues, spatial organization, etc.

Suzan Mazur: Your current research is biotic and environmental events that accompanied the Cambrian explosion of multicellular organisms 500 million years ago. You’re working with some of the oldest complex fossils in places like Namibia, Australia and elsewhere. Is it your view that it’s natural selection every step of the way?

You do accept that mechanisms like self-organization come into play.

Bruce Runnegar: I said that before. The production of change, novelty has probably got many separate ways of doing that. Big jumps in things like going from one cell to multicellular organization may require different mechanisms, from changing the color of the stripes on zebras or something like that. But ultimately the choice of what survives to the present is competition among components of the biosphere that coexist. That’s what we define by the words natural selection. It’s the process that’s operating on all these other mechanisms that makes natural selection kind of universal.

Suzan Mazur: Do you see any evidence of plasticity and a spontaneous emergence of body plans in development say 500 million, 600 million years ago?

Bruce Runnegar: Plasticity, again, I’m not sure what that means. Does that mean that one can transform into another as distinct from both diverging from a common kind?

Suzan Mazur: Ability to change form.

Bruce Runnegar: I think all that’s nonsense. I’m a cladist. I believe that any two things have a common ancestor which looks like neither of them. If you take birds and crocodiles as an example — the common ancestor of any bird and any crocodile didn’t look like either a bird or a crocodile. It looked like something else. Birds have evolved their characters from that common ancestor in one direction and crocodiles in the other direction.

So you can take the same logic back to that time. There was a common ancestor which didn’t resemble anything that we see in the Cambrian. And it provided on one line of one branch something we would see and something on the other side we would see, but the common ancestor of those two were – we can’t necessarily imagine what it looked like because we have no representative of it in the fossil record.

Suzan Mazur: How does the backbone form?

Bruce Runnegar: We know that flies that belonging to a group of organisms known as arthropods have segments. The body is broken up into pieces that are all similar. Vertebrates have the same thing, better seen in a fish than a human perhaps. And we know from the genes that work those, that specify those segment patterns in vertebrates and the genes that specify those segment patterns in arthropods – that those genes predate the last common ancestor of those two groups.

If you go back from your average fruitfly and your average human and ask what did the common ancestor of these two animals look like – you have to say it didn’t look like either a fly or a human. And then it becomes difficult to know because we don’t have any clear representatives of that common ancestor. Probably because they were soft-bodied. Probably small. But we know that they were segmented.

Ultimately, the fact that bones are divided into vertebrae comes from that time when none of us had bones anyway. The bones came along later. But the patterning, the breaking of them up into pieces, comes from a genetic mechanism that existed long before bones.

So it’s not amazing that we have a vertebral column. All the extra bits that go with it – the spine, the attached muscles – all those things can be explained in functional terms. The fact that we’ve got discs between the hard bones is probably just a functional thing because otherwise they’d grind each other away. . . .

Suzan Mazur: You disagree with Roger Buick’s analysis that the 3.47 billion year-old rock in Australia presents evidence of the oldest metabolic process carried out by life – sulfate reduction by bacteria. He’s been quoted in an NAI report as saying life from Mars probably colonized Earth.

You say the fractionated sulfur Buick found is due to exposure to hydrothermal vents and that the barite has always been barite.

Buick argues the fractionated sulfur he found has been through atmospheric processes. He told me in an interview that the debate has moved on substantially and that a French group published an important paper in Nature backing up his findings. Buick says your data has never been published outside conference abstracts.

Would you comment on why you think you’re right and what that means in terms of the origin of life?

Bruce Runnegar: If you’re talking about the original paper, forget about this business of going through the atmosphere because they only measured the ratio of two sulfur isotopes – the most common, which is sulfur 32. And the second most common, which is sulfur 34.

The convention is to take the ratio with the second most common 34, to 32 the most common. So you get a fraction, then you multiply by 1,000, because it’s a small fraction.

If you look at just that in the modern world, you find sulfur-reducing bacteria like sulfate from the ocean, which on the scale that we’re talking about is about +20. And they reduce it to sulfide. That sulfide has a value which is negative. Let’s not even worry about it. It’s less than zero let’s say.

So they’ve shifted the ratio from +20 down to something below zero. And the reason they do this is, or the way they do this is, because they prefer to use the lightest sulfur isotope — sulfur 32, than the slightly heavier sulfur — 34, because it works better in chemistry.

Chemistry likes to do the same thing. But the reactions that chemistry does slow down those temperatures. So ordinary chemistry would do the same thing. It would reduce seawater sulfates to sulfides. But at the temperature of the modern ocean that process hardly works because without the assistance of life, no chemical reaction takes place.

In principle, the two processes don’t have a different result. The only thing that makes it a signature for life is the temperature at which it happens. If it happens at ocean temperature, that’s one thing. If it happens at a hot temperature, that’s another thing. Then it could be either.

With the low temperature of the ocean, it’s just not going to happen without the assistance of life. So then it comes back to what is the environment of the rocks in the deep distant past? Because you have to know what the temperature of this – what was going on at the time. What processes were going on when the sulfides were formed in these ancient rocks

Roger started his career working in that part of the area. Did his Ph.D. on that sort of stuff. At that time they thought these sulfate minerals they found in the rocks had been produced by the evaporation of seawater. There was sort of a marginal, at the edge of the sea lagoon where the water was evaporating. So it would have been seawater temperatures.

The arguments they used for saying these minerals were originally a different mineral are, I believe, not useful. If you accept the argument that they are now barium sulfate and they always were barium sulfate, then you have a different idea of what the original environment was like.

The most plausible thing is that they were made not at hydrothermal vents but by hydrothermal fluids. Because if you have hot rock under the ground, in this case a granite, then water coming from the surface goes down in cracks. It’s fairly cool. When it gets down to near the granite it gets hot and so it rises. And these develop circulation systems in the rocks.

Somewhere it’s going down and it’s cool. Somewhere else it’s hot. The vents occur where it comes up out of the surface But I don’t think these things were out of the surface. They were in the sediments and in the rocks when they were forming. This water going down would dissolve barium from the rocks. That’s where the source of the barium is.

Suzan Mazur: When do you plan to publish?

Bruce Runnegar: I’ve got a year of sabbatical. So sometime this year. I’m hoping to get this into the press by the end of the year.

There are reasons why I don’t think Roger is correct.

Suzan Mazur: Please continue.

Bruce Runnegar: I think these fluids that were coming up were carrying the barium. They were fairly hot. The barium reacted with the sulfate in the ocean which means that the deposition took place near the surface. Barium sulfate is very insoluable and that’s how the sulfate deposits were formed.

Now the question of whether this sulfate was reduced by bacteria or not is another issue that’s more complicated still But I don’t think the evidence is compelling. Let’s put it that way.

Suzan Mazur: And what does this mean in terms of the origin of life?

Bruce Runnegar: I’m an astrobiologist, so I think it’s important that we not raise false hopes. It doesn’t matter very much on Earth. These kinds of investigations and experiments are relatively inexpensive on Earth. You can do all this for a few tens of thousands of dollars. But it’s a highly different matter if you’re going to Mars and spending a billion or two billion dollars returning samples or doing experiments in situ.

I think it’s important that we be very confident about what we can say about data before we make these experiments elsewhere. That’s why I’m taking the very cautious approach of wanting to be 100% sure before saying yes. Whereas, I think some other people maybe are more enthusiastic which is good for astrobiology perhaps, but not perhaps ultimately what we need for these kinds of investigations.

Suzan Mazur: Do you lean one way or another as to where life originated? Do you think it happened on Earth or perhaps on Mars?

Bruce Runnegar: We know that there are natural ways of transporting material between Earth and Mars we didn’t know about 15 or so years ago. We also know from work done at CalTech that some of the rocks we’ve received from Mars, or at least one of the rocks that we’ve received from Mars, hasn’t been heated enough to destroy life by the process of shifting it from Mars to Earth. So it’s plausible that material containing microbes could have been transferred from Mars to Earth anytime in the last four billion years of Earth history.

So if life originated on Mars, it could conceivably have been transferred to Earth by this process. Perhaps less likely going the other way because Mars is a much smaller body and there’s much less likelihood I think – I don’t know this for sure – of getting materials going the other way. But that’s the end of the story.

Nobody knows whether life has ever existed on Mars, and if it did, what kind of life it is. Whether it’s the same as Earth life or not.

Suzan Mazur: And how do you see life originating?

Bruce Runnegar: The origin of life one might expect would be a kind of set of experiments, but I think one of those experiments survived today. That’s what natural selection does. Natural selection ultimately removed all the other failed experiments.

Suzan Mazur: And does natural selection exist throughout the universe?

Bruce Runnegar: I think it should. It’s a process that we see repeated in our own society And that’s the way businesses survive or fail depending on whether customers want the products. Right? That’s natural selection in the case of business. It’s a process that one would think would be universal.

Suzan Mazur: Do you think the Darwinian model is the model we should use in our economics, survival of the fittest?

Bruce Runnegar: I’m not an economist. And that’s an expression which raises all sorts of emotional responses in the audience. But you may know that some of the most interesting models of evolution involve things like game theory. The famous game called the Prisoners Dilemma, where altruism is actually one of the most important components of evolutionary systems. So natural selection doesn’t necessarily mean cutthroat competition, and that’s what businesses I think also realize — that it’s sometimes better to promote biodiversity of businesses rather than try and grind the opposition to a close.

I’m no expert on this, but you only have to look at some of the ways businesses work collectively to realize that it’s not as black and white as much as this description you just said [survival of the fittest] might indicate. I’m all in favor of it in principle, but I’m not in favor of a caricature of the process.

Suzan Mazur: Do you recognize the new Extended Synthesis – the reformulation of the neo-Darwinian theory of natural selection that was kicked off at Altenberg in July?

Bruce Runnegar: I know nothing about it I’m afraid. I’ve been busy in the field.

Suzan Mazur: What is your connection currently to NASA?

Bruce Runnegar: I’m two years beyond some of the post-employment restrictions. I’m firmly disconnected from NASA for the last two years.

Suzan Mazur: Is there a final comment you’d like to make?

Bruce Runnegar: I’ve spoken at length because sometimes a brief comment leads to misunderstanding. I want it to be clear where I stand on these issues because they are contentious.

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Suzan Mazur is the author of Altenberg 16: An Exposé of the Evolution Industry. Her interest in evolution began with a flight from Nairobi into Olduvai Gorge to interview the late paleoanthropologist Mary Leakey. Because of ideological struggles, the Kenyan-Tanzanian border was closed, and Leakey was the only reason authorities in Dar es Salaam agreed to give landing clearance. The meeting followed discovery by Leakey and her team of the 3.6 million-year-old hominid footprints at Laetoli. Suzan Mazur’s reports have since appeared in the Financial Times, The Economist, Forbes, Newsday, Philadelphia Inquirer, Archaeology, Connoisseur, Omni and others, as well as on PBS, CBC and MBC. She has been a guest on McLaughlin, Charlie Rose and various Fox Television News programs. Email: sznmzr @ aol.com

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