LIFE IN SPACE: THE COMPLETE STORY?

Chapter 6L

LIFE IN SPACE: THE COMPLETE STORY?

Astrobiology and what I have called space biology proper do not exhaust the possibilities that space offers to the life sciences. Those possibilities extend to many areas in which our understanding of life may have profound consequences for our interaction with nature. I would like to conclude this chapter by considering briefly three novel areas of investigation.

The first may be called planetary biology, or perhaps global biology. So far I have discussed our attempts to understand micro-organisms, plants, and animals. But we also wish to understand the living environment as a whole and in relation to the other components of the global environment. Planetary biology attempts to achieve this by means of interdisciplinary research that makes extensive use of space techniques for atmospheric sampling and remote sensing. From the remarks made in Chapter 4 it is clear that the study of the role of bacteria and plants in the global environment fits in nicely with the aims of planetary science. Planetary biology expands the scope of investigation and makes the relationship to general planetary science all that more evident. One of its initial aims is to trace the flow of nitrogen and sulfur in the marine environment off the coast of California, and to determine the mechanisms by which different compounds of these elements are converted into others.[1] The eventual goal of this new field is quite ambitious. In Harold Klein's words, it is "to treat the planet as an ecosystem and try to understand the laws of this ecosystem."[2]

A second area of investigation involves the construction of closed environments in space. Until now we have not built any really closed environments up there -- natural wastes are thrown into space, not recycled as on the Earth, oxygen is lost to the vacuum, and so on.[3] Furthermore, the balance of those environments is maintained by artificial means. Whether we can ever built living closed environments in space is a matter of controversy. Indeed, at this time we cannot even determine the minimum size required for a naturally self-sustaining environment amenable to Earth life. But in trying to build one we may learn much. In fact, even artificially closed environments may teach us valuable lessons about terrestrial ecology.

There are several obstacles that limit severely the knowledge we can obtain about an ecological system. One of them is that the amount of variables involved, most of which are interrelated, is simply unmanageable. And even when this obstacle is overcome, the victory seldom lasts long. Normally, a model of a system accounts for changes in one part of the system by changing the amount of reaction in other parts. More sophisticated models may go as far as predicting the rate of such reaction. The problem is that, when confronted with different circumstances, organisms sometimes change not just the amount and rate but the modality of reaction. This problem is illustrated by two examples from a report of the National Academy of Sciences entitled Life Beyond the Earth's Environment: "...many bacteria will use available nitrogen if it is present but in its absence become fixers of nitrogen from the air. Brown hydra in competition with green hydra will, in the presence of abundant food, eat their competitors, and in the absence of abundant food, will float away to some new location leaving the area to the green hydra alone."[4]

Another problem is that a complete description of an ecosystem often requires that we count the numbers of each kind of organism in order to ascertain what it contributes to the flux of matter and energy of that ecosystem. But such counting, for example of worms in the soil, in many cases destroys the ecosystem we are merely trying to describe.

A suggestion for getting around these problems is that we test models of the system in closed versions of it. These models would not attempt to represent every element of the system -- which would be practically impossible -- but would be based instead on a list of the species present and on the roles played by the species presumed to dominate the system. The suggestion is that we build closed environments in accordance with one such model, and then partition them in a variety of ways. We can learn from the interruptions in the normal flows and cycles of the system what its crucial factors are. By disturbing or interrupting the cycle of nutrients, for example, many species may starve while their food accumulates elsewhere, and others may be poisoned by the concentration of toxic wastes that normally would have been washed away. Of course, these partitions do not only take away from the system, in some cases they add to it; just as a dam that interrupts the flow of a river creates a habitat favorable to a variety of organisms that would have been at a disadvantage otherwise.

Intelligent manipulation of this ecology of failure offers the prospect of many exciting questions and experiments. But on Earth there are two serious limitations. One is that the only completely closed system is the Earth itself, which, though open to energy, is relatively closed to matter. Partial closure is of course satisfactory for many investigations, but in some cases we may need greater experimental control. Another limitation is that some closures may be dangerous or undesirable (they may produce very toxic substances, for example). Space offers an opportunity to achieve perfect closure in many investigations that cry out for it; it also permits us to carry out some of the most dangerous experiments in capsules safely isolated from our home planet.

An apparent limitation of space is that larger and richer environments cannot be easily recreated. But there is a sense in which this limitation becomes an advantage. An increased manned presence in space means a greater complexity of man-made habitats, perhaps with a serious attempt to create space agriculture. But this would automatically require that as the ecosystem gets larger we learn more and more about what the crucial flows and cycles are and what it takes to maintain them. A lunar base, for example, can be viewed as an experiment to determine the degree to which environmental sufficiency can be achieved. And a Martian colony may be in a good position to experiment with a variety of environments for agriculture, since the red planet is rich in resources and the colonists may thus have many choices in the composition of such environments. Gerard O'Neill's space colonies may have an even greater potential.

A third area of promise is the invention of new tools to investigate the basic levels of organisms. This point seldom receives the attention it deserves. The absence of gravity permits the development of experimental techniques that are either very difficult or plain impossible on the surface of the planet. I will mention a few ideas that have been suggested over the years, just to catch the flavor of the possibilities.

The technique of electrophoresis, which was described in Chapter 2, can become a useful tool for the production of pure drugs. But its real potential may be found in research instead. For example, our metabolic processes are controlled by about 2,000 enzymes, of which as many as one hundred are mixtures of isozymes. With electrophoresis, we can separate and study those isozymes. If nothing else we can vastly improve our diagnostic skills in matters concerning imbalances and disorders of the human body.

And I think there is reason to believe that this use of electrophoresis in space may herald a new generation of analytical tools for biologists and medical researchers. And that reason is simply that by removing gravity we may not only gain much in purity but also take advantage of the fine operation of electric currents. Some of this fine operation already pays dividends on Earth. Using weak pulsed electric fields, for instance, it is possible to induce cells to fuse, a technique that leads to very unusual new cells. It can be used, among other things, to fuse tumor cells with the spleen cells that produce the specific antibodies that could destroy the tumor if there were only enough of them. The value of one of these fused cells (hybridomas) is that it will make many copies of itself (clones). And all of these copies will produce the same antibody of the original spleen cell, but now in large amounts, we hope, to get rid of the tumor once and for all. I do not know whether this very technique will prove feasible in space.[5] But others kindred to it may find in the advantages of space (purity, effective use of weak currents) the right spark to ignite a new explosion in biomedical research.

Many tools for medical research, and many new medical technologies may come from physics instead. According to an article by John Tierney:

The Russians invented an air scrubber using strong electric fields and cold-plasma chambers to prevent biological contamination of the air in the MIR space station. Now the French-based firm AirlnSpace, with support from the European Space Agency, have refined the Russian invention to create the portable “Inmunair.” According to the firm’s general manager, the system successfully screened anthrax and small-pox substitutes in laboratory tests.[6]

These three areas are mere examples. I have neither the expertise nor the imagination to evaluate all the promise of space biology. Suffice it to say, for now, that space biology is in a position to ask not only new questions but also new kinds of questions. In this, like the rest of space science, it fulfills the function of preserving the dynamic character of science. Some of space biology, the search for origins in particular, merits its pursuit as a main goal. Space biology proper, as I have called it, is in its theoretical and experimental infancy, and will probably have to ride as a passenger of other space undertakings. Nevertheless I have given reasons why it is worth supporting in its own right. For the time being, it can be considered as one of the benefits that come to us from the general exploration of space.

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[1] For example, to what extent is dymethyl sulfide produced by marine algae?

[2] Harold Klein, "The Biological Sciences and NASA," NASA Advisory Council Talk, May 1983, p.5 of the text.

[3] For a discussion of these issues see Life Beyond the Earth's Environment, a report of the Space Science Board of the National Academy of Sciences, 1979 (section in ecology, pp. 105-132); R.M. Mason, J.L. Carden, eds., Controlled Ecological Life Support System: Research and Development Guidelines, NASA CP-2232, 1982; B. Moore III and R.D. MacElroy, Controlled Ecological Life Support System: Biological Problems, NASA CP-2233, 1982; and B. Moore III, R.A. Wharton, R.D. MacElroy, eds., Controlled Ecological Life Support Systems: First Principal Investigators Meeting, NASA CP-2247, 1982.

[4] Life Beyond the Earth's Environment, ibid., p.111.

[5] There are three problems with this technique as a weapon against cancer. One is the difficulty in the formation of hybridomas. In this, weak currents offer some advantages over competing technologies. My guess is that these advantages would be even more apparent in microgravity. A second problem is the stability of the hybridomas. In this, the record of microgravity experimentation should offer some encouragement. The third problem is the selection of the appropriate spleen cell to fuse with the tumor. In this, space does not offer special advantages, unless we consider the possibility of refined techniques of separation and identification.

[6] John Tierney, “Outer Space on Earth: NASA Should Try It,” reprinted in Detroit Free Press, August 2, 2005, p. 7A. Tierney’s derogatory comments are limited to the Space Shuttle. He does believe that much worthwhile scientific exploration can be done otherwise.

A Case for Biological Research in Space

Chapter 6K

A Case for Biological Research in Space

The first general concern about biological experiments in space is that the quality of the research has not been very high. Now, I must admit that there is a clear sense in which this charge is correct: Space biology has not produced any research that would qualify as extremely important. The aim of such research has been to gather the preliminary information that can then serve as the inspiration for hypotheses or as the ground for the testing of ideas. Since, except for the clinical research done for the safety of astronauts, most space biology has taken a back seat to other science, it is not surprising that the information obtained is generally inconclusive and sketchy.

Let me illustrate the nature of the problem by discussing the study of mammalian development. Ideally we would want to determine the role of gravity by observing whether any of the important stages in development is affected in microgravity. The first thing we have to do is look, then. We must look at copulation, fertilization, initial cleavages, embryonic and fetal stages, and postnatal maturation. Many of these are, of course, divided into several distinct and important stages. But we have never been able to observe mammalian copulation, let alone postnatal maturation.[1] The flights open to the biologists have been too short for that.

The situation is better, but not all that much better, with other animals or plants. Fertilized eggs of fish have flown in space.[2] These eggs have hatched successfully, whereas frog eggs have not produced tadpoles. And plants have been made to produce seeds.[3] Unfortunately yields have been low and chromosomal abnormalities common. But some of these results could be accounted for by the stress of flight itself (e.g., the accelerations of take-off and re-entry) or by shortcomings of the life-support systems that make up their artificial space environments. In addition to all that, specimens have normally been examined some time after their return to Earth, when gravity has begun to reverse the effects of its absence. We need to go from seed to seed and from egg to egg -- in space. And we need to do this several times over, so that we can isolate and control factors that belong to the inconveniences of spaceflight other than microgravity. But these multi-generational studies would take months, if not years. And then we also need trained biologists to monitor and examine the specimens in space, where the effects we want to discover take place. Living things must be handled delicately and skillfully if they are to bare their secrets. In more recent flights, the reproductive systems of rats have been damaged, with the ovaries shutting down in females and the testes in males shrinking.

The difference between what needs to be done and what has been available makes space biology appear primitive. To a critic, the space biologist's collections of data may resemble the wasteland of empirical social science. Or as someone might say, it is just Baconian science -- without theoretical direction, and thus without theoretical interest.

The critic burdens them with a Catch 22, space biologists feel. To show how their field may be significant they must carry out enough investigations so they can begin to ask fruitful questions. But critics object to those investigations on the grounds that space biology has not yet been shown to be significant.

It may be useful to compare the situation of space biology to that of atomic physics at the beginning of the 20^th century and to that of particle physics during the 1960s: Physicists would accelerate particles, crash them against targets, and analyze the debris created in the collision (in atomic physics the aim was to determine the structure of atoms by the deflections of the electrons that crashed against them, in particle physics to discover particles and determine their properties). There is a sense in which the particle and atomic physicists were just "fishing," as the space biologists are now accused of doing.

Critics will no doubt rush to argue that there is a big difference. That difference is presumably is that they were fishing in fundamental waters. Whatever they found would have the most significant consequences. But that is easy to say in hindsight. The proliferation of particles in the 1960s led many to think that further searches -- and extremely expensive searches at that -- would amount to just looking around without any theoretical purpose of note, a Baconian end to a century of exciting physics. As for Rutherford and the other atomic physicists of the turn of the previous century, they were fishing in domains that most other physicists would not even agree were real, let alone significant.[4]

Hindsight is, of course, a wonderful sense. Today we can see that all those particle surveys in the 1960s allowed physicists to classify the particles into families--a classification not unlike that of the chemical table of elements -- and then to propose new theories about the structure of matter. Thus the quark hypothesis and a new era of physics were born.

In both cases, however, it took great vision to see the promise of the research. Some important physicists did think that Rutherford was onto something. They held the notion that fundamental aspects of nature might be explained by discovering how matter was put together at the most elementary level. Many decades later, after discovering so many elementary particles, physicists generally thought that the problem was how to make sense of the array. And thus what might have looked as hack work from a point of view, from another it seemed as the preliminary taxonomy essential for the physics of the future.

My point is precisely that space biology should be given the chance to carry out that preliminary taxonomy, even if it looks like hack work to some critics. The warrant for doing so is the same as in the two cases from the history of physics: the theoretical pay-off comes from testing matter well beyond the range that we have examined previously.

This warrant is clearly seen in the case of some sciences. Take space astronomy, for example. Once we could detect the entire electromagnetic spectrum by placing our telescopes and other instruments above the atmosphere, we embarked in a new survey of the heavens. It may have seemed that we are just looking around. But we had good reason to suspect that what we would find would be significant, that our ideas would be challenged to the utmost. And that reason was precisely that we knew how limited our range of observation had been until then. [5]

In space biology, unlike space astronomy today, but like space astronomy not long ago, we cannot specify the great scientific rewards that await us. We know, however, that the gravity of the Earth has been a constant throughout the evolution of life. We also know that the more pervasive a constant, the more difficult it is for us to determine its role, if any. That is exactly what happens with gravity. How are we to proceed, then? First of all, we cannot resolve the matter by further standard biological analysis. For in analysis we use the tools of prevailing theory to investigate some phenomena. To discover that role by analysis is therefore practically impossible, since nothing in our previous biology makes gravity a crucial element of the theory. What we need is either an alternative theory in which gravity is assigned a specific role, or else the manipulation of gravity to make present theory fail. We can do both.

These new theoretical and experimental directions are suggested in part by some of the early results of space biology, and in part by emphasizing some relevant aspects of standard theoretical biology. They will permit us to show the mistakes in the two notions that buttressed the general low estimate of the value of space biology. The first notion, we may recall, was that microgravity affects organisms only at the systems level. Investigations then have the main purpose of determining just what systemic effects take place and how they can be corrected. This clinical work has made its practitioners confident that with appropriate compensation (diet, drugs, and exercise) men and women can survive in space for periods of many months, perhaps years.

But even if this is true, it takes away nothing from the promise of space biology proper. If we wish to determine the role of gravity as an all-pervasive factor in individual development and in patterns of evolution, the systems level is actually not a bad place to begin. The human body, for instance, appears fine-tuned for the Earth's gravity. We might have expected to extrapolate our centrifuge studies here on Earth (with gravities above 1g) to the microgravity of space. Thus if we lose body mass under an acceleration of several g's, have it normal at 1 g, then presumably we would gain mass at less than 1 g. But it turns out that we lose mass at less than 1g. (The body mass in question here is intracellular mass and does not include fluids or calcium loss in the bones, which is itself pronounced and very worrisome. Similar reactions take place in microgravity with temperature control and other physiological functions. The explanation of some of these reactions seems to be that the shift in body fluids that comes from changes in gravity affects the communication between cells.)

This fine-tuning of physiology to the Earth's gravity -- which is seldom emphasized if realized at all -- should provide a fruitful theoretical perspective to study the relationships between a variety of internal systems and cycles in the human body. Why are physiological functions maximized at 1 g? This leads to questions about why the body works as it does, questions that would not occur that easily otherwise. A preliminary answer is that gravity is used to harmonize a variety of physiological systems. One way to think about this is that gravity is like the glue that holds such systems together. Once the glue is gone, they do not quite work together. And from their failure we learn what makes them work correctly under terrestrial conditions. Another way to think about it is that those systems change their responses in order to adapt to the new conditions. That may also give us significant clues about their normal modes of interaction with other systems or mechanisms.

This fine-tuning to 1g may become acute in issues of development. In microgravity a human male excretes from 1.5 to 2 liters of body fluids, with pronounced reductions in the levels of sodium and potassium. By contrast a pregnant human female is expected, in 1g, to show an increase of 1.5 to 4 liters over her pregnancy, with a marked retention of sodium. Since the development of the fetus follows a strict sequence in which each event must take place within a critical period, and since the availability and composition of the body fluids is essential to the proper environment in the placenta, we can readily see that disruptions at the system level affect physiological processes at lower levels. At the present time it would be morally impermissible to have pregnant women in space.

The human body is resourceful; it may be able to compensate for the effects of microgravity in a systematic fashion even during a pregnancy. But to determine whether it can, we must resort to experiments on animals.[6] By removing gravity, then, we can observe how the development comes unglued; by "dialing" several degrees of gravity we can refine our examination. The mere fact that many systems function optimally at 1 g provides warrant for designing experiments to determine how the timing and feedback controls of development operate. This, it seems to me, is not a matter of small importance.

"Mere" systemic effects can have profound repercussions. A clever probing of them can reveal much not only about development but also about the operation of many physiological functions, including their coordination. This possible gain in knowledge may extend to the cellular level, in spite of the experiments on cells mentioned earlier. The cells of complex organisms are parts of cellular systems, for example, of specialized tissue. The role cells play in those systems largely affects how the structural elements of cells operate. Those structural elements (called cytoskeletal) are responsible for communication among cells, transportation of plasmas, and maintenance of the cells' compartments. Changes in the environment of the cell lead to cellular changes in shape, in ability to move, and in internal metabolism (i.e., polarity, secretion, hormone regulation, membrane flow, and energy balance).[7] Changes that take place at the systems level in the organism, such as body fluid shifts, are bound to affect several cellular systems, change the cellular environment, and thus affect the cells themselves.

The experiments that indicated that gravity was irrelevant at the cellular level were performed in cell cultures; they did not examine cells that formed part of the complex wholes that are the cells' normal environments. It is not surprising, then, that such experiments could not expose the indirect action of gravity that starts at the systems level of the organism and works its way down into the realm of the small.

Since genes contain the “language of life,” and since organisms are presumably the books written in that language, we tend to think that significance in biology goes from the small to the big. But we have just seen that much of the small depends on the big, since the function of the small depends on the larger whole to which it belongs (and that whole often depends on an even larger one of which it is a part, and so on). It is true, however, that genes are in some sense supposed to be independent of the organism's environment: Theory demands that genetic variation not be coupled to the mechanism of selection (i.e. that the environment cannot have a hand in inducing the variations that are compatible with it, otherwise it would be possible to inherit acquired characteristics). Nonetheless, even if this demand is strictly interpreted,[8] many molecular processes may still be open to the influence from above I have just discussed.

It is also true that, in many areas of biology, real and fundamental progress is achieved when a strong connection can finally be made to the genotype of the organism in question; that is, when we can finally explain how the genes give rise to the mechanism or function in question. Be that as it may, it is misleading to think of genes as the blueprint of some sort of archetype that the organism will grow into, barring acts of God and other misfortunes. Given a certain genotype -- and the right circumstances at many different stages of development – a certain individual organism will likely be the outcome. But at many critical junctures within those stages of development, things could go slightly differently. The outcome would be a different organism.

The important point for our issue is that at those critical junctures, genes and the various structures to which they give rise take advantage of many environmental constants in order to keep their appointed rounds. Nature does not create everything anew and at once. It takes advantage of what is already there; it builds on the structures it finds in place; it develops not by reaching for an ideal but by a process best described as jury-rigging.

My suggestion is, of course, that the fine-tuning of several physiological functions for 1 g indicates that gravity is one of those constants that provide the context in which the language of life comes to make sense. Without it, aspects of the human genotype would be expressed very differently, if they could be expressed at all. If my suggestion is correct, the manipulation of gravity could return a theoretical profit to the study of genetics in space.

The reason becomes clearer if we emphasize some of the points already made. It is not easy to discover genes and then ask what they do. Often the question goes from the top down: given a certain function or structure, how do genes contribute to bring it about? This indicates that we need knowledge of all the other levels in order to guide genetics. Moreover, it is not necessary that all the alignments and states of equilibrium that many physiological systems reach be encoded in any one set of genes. Some genes may have been selected for because they lead to the construction of an organ or function that finds accommodation with earlier organs or functions. And the genes that lead to those earlier organs or functions are now preserved because the new arrangements are advantageous to the organism as a whole.

The point is this: Even if we knew what genes brought about the newer organ or function, and even if we knew all the steps in the construction, we still would not understand that aspect of physiology. For those genes and those steps make biological sense only against the background of the existence of those other organs or functions. And all these together make sense only in the context of whatever constants a form of life has come to take for granted. Thus, for example, the pattern of a net of nerves may not be encoded in the genes. The only "instruction" may be for the nerves to keep growing in search of a particular chemical attractor, but since the tissue in which they grow does not permit easy penetration, the nerves have to work their way around. (See Figure 10) The result is a very specific kind of net, although nowhere in the genotype could we find the "blueprint" for such a net.[9]

The moral of this story is that knowledge of one level – even if it is "fundamental" – is very limited without knowledge of the other levels. But this more complete knowledge can be gathered only to the extent that we grasp the context in which genes find ultimate expression. And that requires the manipulation of constants in order to determine their role.[10]

I have already suggested some reasons why gravity is one of those relevant constants. It may turn out, of course, that the actual threshold for the proper functioning of physiological and developmental is less than 1g; that as soon as a gravity vector (direction and intensity of gravity) is detected, things will work normally or almost normally. Determining that threshold is one of the important initial tasks of biology in space (that subdivision of the field is called "gravitational biology"), a task that finds no counterpart in doing centrifuge studies on the Earth.[11]

But there are other ways in which genetic studies can be done advantageously in space. In a recent experiment samples of salmonella bacteria flew in the Space Shuttle while control samples under identical conditions, except for the presence of gravity, remained on the ground. The space-traveling salmonella became much more virulent because certain genes changed their level of activity in microgravity – genes crucial to the control of a protein called Hfq, which allows bacteria to adapt to changing conditions[12]. This finding, worthwhile in itself, may also help us understand some causes of increased virulence of such bacteria on Earth.

It may turn out that we can discover how to compensate for most of the systemic disturbances caused by microgravity in an organism over long periods of time. That would be ideal. We must recall that in many instances proper experimentation requires multi-generational studies, and that multi-generational studies may take years. Not only could we benefit from investigating the effects of microgravity on a variety of organisms, but we could do so without risking serious damage to the biologists carrying out those investigations in space.

The experimental and theoretical promise of space biology is thus far greater than we may imagine from glancing at a few reports of the rather pedestrian biological experiments that have been done so far. Two further considerations should give solid anchor to this conclusion. The first is conceptual; the second is historical. H.A. Lowenstam and Lynn Margulis have argued convincingly that the ability by eukaryote cells to modulate their internal concentrations of calcium made possible the appearance of calcareous skeletons.[13] The appearance of such skeletons in turn made possible, over 500 million years ago, the Cambrian Explosion, during which all the major divisions of life became established. The importance of this argument, for our purposes, is that calcium metabolism is one of the first things affected by microgravity.

Calcium ions in solution are essential for many physiological functions, including cell adhesion, muscle contraction, amoeboid cell movement, and -- as it is now acknowledged -- they are also used to transmit information between cells. Not only is the intracellular regulation of calcium essential to the function of eukaryote cells, it is also important in the genesis of tissues and embryos. The regulation of calcium seems to be one of those physiological functions on which nature has built a whole array of other functions. This key evolutionary role apparently began, according to Lowenstam and Margulis, when "prey, forced to escape from more effective predators, developed highly integrated sensory and motor systems that must have involved increased coordination and speed of the muscle system."[14] These two skills depend on muscle contraction. And muscle contraction "responds directly to calcium release."[15]

Since the regulation of calcium may have been very instrumental in the evolution of complex organisms, and since life develops in a jury-rigging fashion, the biological importance of calcium may go far beyond what standard theory assigns to it. Determining that importance is precisely one of the areas where experimentation in space can be of advantage. This consideration thus provides one more reason for thinking that in space biology, too, exposure to new circumstances may lead to the profound transformation of our ideas.

The examination of the role of gravity in living things has paid off from the beginning. It was Darwin himself who first noticed that the tips of growing roots and shoots were used to detect gravity. "We now know," he said, "that it is the tip alone which is acted on, and that this part transmits some influence to adjoining parts, causing the latter to bend."[16] The study of this influence, in a long series of experiments beginning with the publication of Darwin's work in 1880, yielded the separation (1920's) and chemical identification (1930's) of the first hormone known to make plants grow.[17] Space biology proper seeks the opportunity to continue this history.

Nevertheless, even if these considerations are admitted, the question remains whether the large expenditures of space biology are justified when its significance is more of promise than of record. “$50,000 can pay for a decent experiment in standard biology today,” a biologist told me in the 1980s. But for that money we could hardly get a rabbit into orbit, to say nothing of enough rabbits for biologists to supervise multi-generational studies in space. We must notice, however, that this complaint does not deny that space may be beneficial to biology, or that it may be beneficial in important ways. Its aim is rather to make us favor Earth-based investigations -- which we already know are very important -- over the expensive biological experimentation in space.

Space biologists often respond in two ways. First they point out that their budgets have been small as space budgets go (in the 1980s, for example, it was about $30 million a year -- including the monies for exobiology, gravitational biology, and flight experiments -- which was roughly about 3% of the total space science budget, and not much when compared to all the monies spent for biological research on Earth). Their second point is that most of the money for space biology is not going to come from the general funds earmarked for the life sciences. The money is going to come from space exploration funds.

Critics are unlikely to accept these two points. First of all, even if the space biology budget is a pittance, to do the research properly would take far greater amounts. For example, if space biology is used as one of the justifications for building the space station, we would have to think in terms of hundreds of millions of dollars. As for the second point, to say that the two are not really in competition for the same monies is an easy out. For whatever the name of the account, in the long run society pays for both. Why should space biology take so large a share?

Nevertheless the matter is not as simple as that. Space biology does indeed belong to a large space commitment. Because of that, the notion of competition between standard biology and space biology flounders. To see why, imagine what happens to a man who buys an automobile and wants a radio in it. For the amount of money that he will have to spend, he could have gotten several radios far superior to the one that goes into his car. But those radios would not do quite the same job effectively. Similarly, since we are going into space we have an opportunity to investigate life in ways not open to us before. The whole question of doing space biology must then be taken in the context of having a space program, just as the question of having the car radio arises in the context of having a car and not in that of purchasing radios generally. All the while we must keep in mind how promising a radio this is.

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[1] From the "Final Report of the Developmental Biology Working Group," p.3. (Not yet published, extended to me as a courtesy of Dr. Emily Holton).

[2] For a brief summary see G.R.Tylor (Note 19), p.103. For a full report see H.W. Scheld et al, "Killifish Development in Zero-G on COSMOS 782," p.179, NASA TM-78525. Unpublished Soviet studies, however, have raised serious doubts, in J.R. Keefe's opinion, "about the ability of normal vertebrate fertilization under spaceflight conditions." ("Gravity is a Drag," p.6. Unpublished).

[3] See the Annals of Botany supplement cited in Note 17. Dr. Holton has made available to me data from Soviet experiments that show very low yields and that suggest that flowering and fertilization may be sensitive to gravity (as indicated, for example, by lost chromosomes in Dwarf Sunflower and broken chromosomes in oats). When cells are studied not in culture but as part of a system, there is a peculiar increase in chromosomal abnormalities in the majority of organisms, including humans. See, for example, L.H. Lockhart, "Cytogenic Studies of Blood (Experiment M111)," Biomedical Results from Skylab, op. cit., p.217. Investigators are much too quick, in my opinion, to explain away such widespread abnormalities as possible effects, exclusively, of flight stresses.

[4] Whether atoms existed at all was a matter of controversy amongst physicists. Ernst Mach, for example, argued that their existence was not a scientific claim. The controversy was settled in 1905 with the publication of Einstein’s work on Brownian motion.

[5] We might ask whether it is fair to have to spell out the warrant for investigating the role of gravity in biology. After all, the history of science is full of cases where investigations that were considered preposterous led to the most profound changes in thought. But we cannot take this easy way out when space biology requires large sums of money and its critics have credentials and influence. The issue must be faced.

[6] Of particular interest would be animals who exhibit a highly differentiated ability to distribute fluids (e.g., Gerbilline rodents). "Final Report of the Developmental Biology Working Group," op. cit., p.6.

[7] Ibid. p.5.

[8] Every system of the organism tries to maintain homeostasis (a relatively stable state of equilibrium) against the next higher level, and the organism as a whole against the environment. Thus the genes benefit from many levels of homeostasis serving as a buffer zone against the environment. Nonetheless it is clear that the general environment sometimes will affect the intracellular environment and thus may conceivably act as an agent of selection against some pieces of DNA and in favor of others (at the molecular level, that is). This is not to say that acquired characteristics can be passed on, since the features of the environment that will favor some traits at the level of the organism are not of a kind with those that would act on pieces of DNA within the cell. That is what happens, for example, when a change in the cellular environment may permit a mutation to survive which will later be considered a defect of the organism vis. a vis. the general environment.

[9] Stent's work on nerves.

[10] I take it that the general point I am defending here is a corollary of the views I expressed in Chapter 8 of my Radical Knowledge: A Philosophical Inquiry into the Nature and Limits of Science, Hackett, 1981. It is also an expansion of Gunther Stent's work on the "meaning" of the genetic code.

[11] In general, centrifuge studies can be extrapolated to space conditions only with the greatest of cautions.

[12] This example is taken from S. Williams, “Bugs in Space.” Science News, 2007, September 29, Vol. 172, p. 197.

[13] H.A. Lowenstam and Lynn Margulis, "Evolutionary Prerequisites for Early Phanerozoic Calcareous Skeletons," BioSystems, 12, 1980, p.27.

[14] Ibid. p. 36.

[15] Ibid. See also, S.J. Roux, ed., The Regulatory Functions of Calcium and the Potential Role of Calcium in Mediating Gravitational Responses in Cells and Tissues, NASA CP-2286,1983.

[16] C. Darwin, assisted by F. Darwin, The Power of Movement in Plants, John Murray, 1880, p.592.

[17] Adapted from the Dedication to Charles Darwin in the Proceedings of the Sixth Annual Meeting of the IUPS Commission on Gravitational Biology, op. cit.

A NEW CONTROVERSY

A NEW CONTROVERSY

I have run across a new controversy concerning fossils from outer space, this time about structures that resemble Cyanobacteria. These structures were found in a meteorite by a Richard Hoover, a NASA scientist. His paper was published by the Journal of Cosmology, an online journal. The official NASA word has been negative, apparently, and the same can be said for the opinion of the scientific elite that has gotten wind of this paper. I am very skeptical of some of the claims that the paper’s supporters have made, but I thought that many of my readers might want to take a look for themselves. I am enclosing two items below. One is an open letter to the editors of Science and Nature, the top two general science journals in the world, by the editors of the Journal of Cosmology. The other is a synopsis of Hoover’s presumed discovery. By going to the journal’s website you may also view several commentaries by people with PhD’s in science, some sensible and some not. The materials can also be found in the newsletter

Journal of Cosmology, 2011, Vol 13,
JournalofCosmology.com March, 2011

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Fossils of Cyanobacteria in CI1 Carbonaceous Meteorites
Richard B. Hoover, Ph.D. NASA/Marshall Space Flight Center

Synopsis

Richard Hoover has discovered evidence of microfossils similar to Cyanobacteria, in freshly fractured slices of the interior surfaces of the Alais, Ivuna, and Orgueil CI1 carbonaceous meteorites. Based on Field Emission Scanning Electron Microscopy (FESEM) and other measures, Richard Hoover has concluded they are indigenous to these meteors and are similar to trichomic cyanobacteria and other trichomic prokaryotes such as filamentous sulfur bacteria. He concludes these fossilized bacteria are not Earthly contaminants but are the fossilized remains of living organisms which lived in the parent bodies of these meteors, e.g. comets, moons, and other astral bodies. Coupled with a wealth of date published elsewhere and in previous editions of the Journal of Cosmology, and as presented in the edited text, "The Biological Big Bang", the implications are that life is everywhere, and that life on Earth may have come from other planets.

Members of the Scientific community were invited to analyze the results and to write critical commentaries or to speculate about the implications. With one exception as it was off topic, all commentaries received were published between March 7 through March 10, 2011. By far, most of the commentaries were positive and supportive of the evidence.

Open Letter to the Editors of Science & Nature

The Journal of Cosmology Proposes a Scientific Commission,
Established Co-Jointly with Science and Nature,
To Investigate & Confirm the Validity of the Hoover Paper

March 11, 2011

Dear Dr. Bruce Alberts and Dr. Philip Campbell:

In 1584, Giordano Bruno published "Of Infinity, the Universe, and the World" and wrote: "There are innumerable suns and an infinite number of planets which circle around their suns as our seven planets circle around our Sun." According to Bruno, we are unable to see these planets and suns "because of their great distance or small mass." On February 19, 1600 Bruno was tortured and burned at the stake by the Inquisition for publishing these claims which contradicted established "scientific" dogma.

The publication of Richard Hoover's paradigm shattering discovery of microfossils within carbonaceous meteorites, unleashed an ugly storm of violent, histrionic invective not seen since the Middle Ages when they burned scientists for making discoveries that threatened the established order. Charlatans and quacks quickly emerged, and the media unabashedly published their ravings, recklessly casting delusional filth upon the reputations of the Journal of Cosmology and its editorial board, and the hundreds of esteemed scientists whose peer reviewed work we have published; a roster which includes two Senior Scientists Science Directorates at NASA, over 30 top NASA scientists, and four astronauts.

How can science advance if the media and NASA administrators promote frothing-at the-mouth-attacks on legitimate scientists and scientific periodicals who dare to publish new discoveries or new ideas? Skepticism is natural. Doubt is healthy. But science cannot progress under a cloud of intimidation and fear.

The Journal of Cosmology (JOC) has reviewed its editorial policies and peer review procedures and determined they are sound. The media has been provided a sample list, the names of nearly 100 top scientists who have served as referees in the past; a veritable "who's who" of the top experts in the world have reviewed papers for JOC.

Hoover's paper was received in November and was repeatedly peer reviewed. After months of careful analysis, it was published on March 5 of 2011. Of the 24 commentaries received, almost all have been supportive of the findings. The results are valid. We have been provided with no evidence they are not.

The implications of Richard Hoover's discoveries are profound. However, given the slanders and paranoid ravings designed to crush all rational discussion of these findings, naturally the public, the media, and the scientific community would be skeptical. They deserve to know with absolute certainty if these findings can withstand the scientific scrutiny of esteemed experts and if his results should be accepted or dismissed.

How can this issue be successfully resolved? Who can the public trust? Science magazine which published the "arsenic-life" study which proved to be untrue? NASA's chief scientist who backed the bogus "arsenic" paper, and has made a number of grossly inaccurate and untruthful remarks about the Hoover issue? The Journal of Cosmology whose reputation has been besmirched by reckless slanders? Nature magazine which has rejected Nobel prize winning research?

Given the ugly climate which now prevails, the validity of the Hoover paper must be resolved as a cooperative effort, through an unprecedented collaborative peer review, monitored and mediated by the Journal of Cosmology and its critics and competitors (Science and Nature), thus guaranteeing a balanced approach and so all points of view are represented. Therefore, the Journal of Cosmology proposes that:

1) JOC, Nature, and Science each appoint an expert-judge who has a background in astrobiology.

2) These 3 expert-judges will appoint and unanimously agree on a panel of 12 esteemed experts who will be guaranteed anonymity if they desire.

3) This expert panel of 12 will have 30 days to review the Hoover paper, ask for supplementary material, and to question Richard Hoover and to call upon the expertise of additional experts, if they so choose. Each of these experts will issue their reports to the 3 expert-judges.

4) The 3 expert-judges will issue their own report(s) summarizing these findings, and issue a verdict on or their opinion of the validity of Hoover's paper as based on the reports issued by the 12 expert panel.

5) Science, Nature, and JOC, will publish the reports of the 12 member expert-jury, and the expert-judges.

6) If the weight of opinion is that Hoover's findings are not valid, the Journal of Cosmology will withdraw the paper.

7) If Hoover's findings are validated, we ask not for a apology, but congratulations.

We believe our proposal is scientifically sound and eminently reasonable. We are completely open to working out the fine details with the editorial boards of Science and Nature

If Science and Nature decline, then any refusal to cooperate, no matter what the excuse, should be seen as a vindication for the Journal of Cosmology and the Hoover paper and an acknowledgment that the editorial policies of the Journal of Cosmology are beyond reproach. The very fact that we have made this proposal, coupled with all our previous efforts to open this issue to scientific discussion and debate, is, itself, testament to the integrity of JOC whose mission has always been to promote and advance science.

Sincerely,
Rudy Schild, Ph.D.
Center for Astrophysics, Harvard-Smithsonian
Editor-in-Chief
Journal of Cosmology

THIRD CHALLENGE: SPACE BIOLOGY

Chapter 6A

THIRD CHALLENGE: SPACE BIOLOGY

The well-being of human life has been the ultimate justification for the physical branches of space science. But can we justify the space science of life itself? What is the value of doing biology in space? Many observers, space scientists included, do not think highly of the scientific prospects of the field. The main purpose of this and the next few postings is to meet their objections, to show that the study of life in space also shows the serendipitous, deep practicality of the other space sciences.

Space biology can be roughly divided into two main areas. The first investigates the possibility of extraterrestrial life; it goes by the name of exobiology, or, more recently, astrobiology. The second investigates the behavior of terrestrial life in outer space; it corresponds to the idea most laymen have of space biology[1]. Since these two areas are distinct, they require separate analysis and separate justification.

Exobiology/Astrobiology

Introduction.

It used to be said with derision that exobiology is a science without subject matter. We have never found any alien life, and for all we know terrestrial life might be the only life in the universe. Or even if there is life somewhere else we might never find it. Or if we stumble upon it by chance, we might not recognize it as life.

Exobiology did have its moment of fame in 1975 with the Viking missions to Mars; but, after the Viking landers failed to find life, the field steadily declined in prestige and seemed moribund until two extraordinary developments resuscitated it.

The first was the dramatic advance in the search for planets around other stars. In the last few years hundreds of extraterrestrial planets have been discovered, most of them gas giants even larger than Jupiter, but we are also beginning to find rocky planets a bit larger than the Earth. This development was extraordinary because even the best telescopes were not expected to take pictures of planets many light years away from us. Some researchers had claimed to detect the presence of large planets by the wobble they caused on the paths of their parent stars, but it was generally agreed that such “wobble” was comfortably within the margin of error of the observations. Researchers hoped that a generation of space telescopes yet to come might help, until some clever astronomers invented a completely novel approach: the tug and pull of a planet on a star, if they are both on our line of sight, will make the star move away or toward us. That means that the star’s light would be shifted towards the red, if the star is moving away from us, or towards the blue if it is moving towards us. Spectral analysis, thus, has made the discovery of new planets routine. The planets found so far are very close to their stars, even closer than Mercury is to the Sun, but that is not to say that all extraterrestrial planets are that close. It should be expected that the first planets we found by measuring how much their gravitational pull disturbs their stars’ orbits should be precisely those that are very close to their stars. All these discoveries have been supplemented by the observations, with infrared telescopes mostly, of planetary systems in formation – observations that make plausible the existence of terrestrial planets throughout the galaxy.

The second extraordinary development was the discovery of organic compounds in a Martian meteorite (ALH84001), and the tantalizing suggestion that some worm-shaped structures found inside might be fossils of extremely small Martian bacteria. The monumental excitement created by the announcement led to a very ill-tempered controversy between groups of scientists that I will discuss later in this section. Both sides would agree, however, that the discovery of extraterrestrial life would give us good reason to get excited. For by comparing terrestrial and extraterrestrial life we would learn much about our own life and our own planet.

We can readily see that the possibility of such a comparison may provide an excellent motivation for the pursuit of exobiology, and so this will be the first issue I will discuss. I will then examine the negative results of the search so far and evaluate the hope created by the Martian meteorite. And, finally, I will determine why it makes sense to continue doing astrobiology even in the face of uncertain results.

1. The Motivation for Astrobiology

What would extraterrestrial life enable us to learn about our own kind of life? The answer is clear. All life on this planet is based on the same carbon chemistry and apparently all have the same genetic code. Of the many possible amino acids, only twenty are used to build proteins. DNA, the reproductive code for terrestrial life, makes use of only four bases. Moreover, organic molecules can be left handed or right handed, but terrestrial life prefers left-handed amino acids and right-handed sugars. Are these circumstances mere accidents of organic evolution, or are there fundamental reasons why life has taken these particular turns on this planet? Even one other kind of life would permit us to make great strides in examining these matters. For that other life may use a wider range of amino acids and bases, or it may prefer right-handed amino acids or left-handed sugars. One result of such a finding may be that, say, a particular chemical balance in the Earth’s oceans caused the preference for left-handed amino acids. Or the alien life may be similar to life on Earth, which would reveal to us some sort of organic inevitability. In either case, if we have knowledge of the natural environments of that alien life, we can begin to understand why certain paths open to organic evolution are conducive to replication. The new perspective would be very fruitful in trying to understand our own biology at all levels.

It would be especially useful to observe stages of organic evolution and to study life as it begins in a new world, or at least to find fossil records of such beginnings. Beyond the stage of primitive cells, radically different alien forms of life would still offer great rewards, as we will see below. Even if perchance organic evolution produced in two similar planets similar primitive cells with essentially the same genetic code, the subsequent evolution would have much to teach us, for life in those two planets would undergo different histories of adaptation. Imagine, for example, that the now famous Alvarez asteroid had not crashed on the Earth. No one knows how dinosaurs would have continued to evolve, but it is possible that their grip on the surface of the planet would have been further strengthened. Mammals might have been thus forever condemned to crawl and scratch in the night like so many other vermin.

Even similar planets are likely to exhibit different tectonic histories. Plate tectonics brings continents together or breaks them apart; it throws chains of mountains up over the landscape; and it creates volcanoes where the plates rub against each other. In doing so it brings some habitats to an end and others into existence; it destroys; it influences; it changes life in many ways. Consider how the variation in the size of landmasses influences the fauna and flora of a planet. Certain large animals, for example, need a large environment in which they can roam for long distances. Elephants used to travel many hundreds of miles in their annual migrations. As these big mammals went along, they ate a variety of plants, thus insuring a balanced diet and permitting the vegetation at every feeding stop enough time to recuperate. Their considerable droppings were recycled, in the meantime, by armies of insects and bacteria. In a much smaller environment the vegetation would have been devastated, and the elephants would have suffered from poor diets and the unsanitary rot of their own excrement.[2] They would not have been fit.

Slight differences at the beginning of the history of a planet would alter the make-up of the crossroads that life has to face, first at the level of organic chemistry, and then at the level of cells — presuming that cells are common to living things. A eukaryotic cell (a cell with a nucleus) may well be the result of symbiosis between different varieties of prokaryotic cells (without a nucleus).[3] For example, the mitochondria in eukaryotic cells (see Figure 1) may be the remnants of prokaryotic cells that discovered how to use oxygen for energy and were swallowed but not digested by larger bacteria. Since eukaryotic cells are the building blocks of all complex organisms on Earth, we can imagine that different symbiotic relationships between primitive cells might have led to forms of life vastly different from those of our acquaintance. On planets so endowed, the subsequent interaction of life with the rest of the environment would have a multiplier effect, for they would change their environment in novel ways, and those new environments would lead life to adaptations that on Earth could meet only with misfortune.

Acquaintance with such alternative biotas would inevitably lead to profound transformations in biology, since biology would grow, and scientific knowledge seldom grows without changes. In this, scientific knowledge resembles animals. Mammals, for example, did not just get bigger after the extinction of the dinosaurs. As their size increased, the structure of their skeletons had to change to accommodate their larger weight. In a planet with gravity similar to ours, a dog the size of an elephant would probably look much like an elephant. In an analogous manner, a science of biology that were suddenly much larger in subject matter would have to grow connections and supporting structures for which there was little need in the days of a single biota.

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[1]. I do not divide the field in the manner that NASA has found convenient for a variety of administrative reasons (according to which, for example, Space Biology is only a small section of the Life Sciences Division). My division follows rather the convenience of the argument and of the reader.

[2]. Adapted from R.M. Laws, I.S.C. Parker, and R.C.B. Johnstone, Elephants and their Habitats, Clarendon Press, Oxford (1975).

[3]. For an informal, though detailed account of these issues see Gene Bylinsky, Life in Darwin's Universe, Doubleday, 1981.