Τρίτη, 31 Ιουλίου 2012

THE AUTONOMY OF BIOLOGY ...ERNST MAYR




It took more than two hundred years and the occurrence of three sets of events before a separate science of the living world—biology—was recog- nized. As I will show, one can assign these events to three different sets: (A) the refutation of certain erroneous principles; (B) the demonstration that certain basic principles of physics cannot be applied to biology, and (C) the realization of the uniqueness of certain basic principles of biology that are not applicable to the inanimate world. An analysis of these three sets of developments has to be done before one can accept the view of an autonomy of biology. For an earlier support of the autonomy of biology see Ayala (1968).

THE REFUTATION OF CERTAIN ERRONEOUS BASIC ASSUMPTIONS Under this heading, I deal with the support for certain basic ontological principles that later were shown to be erroneous. Biology could not be recognized as a science of the same rank as physics as long as most biologists accepted certain basic explanatory principles not supported by the laws of the physical sciences and eventually found to be invalid. The two major principles here involved are vitalism and a belief in cosmic teleology. As soon as it had been demonstrated that these two principles are invalid and, more broadly, that none of the phenomena of the living world is in conflict with the natural laws of the physicalists, there was no longer any reason for not recognizing biology as a legitimate autonomous
science equivalent to physics.

VITALISM The nature of life, the property of being living, has always been a puzzle for philosophers. Descartes tried to solve it by simply ignoring it. An organism is really nothing but a machine, he said. And other philosophers, particularly those with a background in mathematics, logic, physics, and chemistry, tended to follow him and operated as if there were no differ- ence between living and inanimate matter. But this did not satisfy most naturalists. They were convinced that in a living organism certain forces
Museum of Comparative Zoology, Harvard University, MA 02138, USA. Ludus Vitalis, vol. XII, num. 21, 2004, pp. 15-27.

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are active that do not exist in inanimate nature. They concluded that, just as the motion of planets and stars is controlled by an occult, invisible force called gravitation by Newton, the movements and other manifestations of life in organisms are controlled by an invisible force, Lebenskraft or vis vitalis. Those who believed in such a force were called vitalists.

Vitalism was popular from the early seventeenth century to the early twentieth century. It was a natural reaction to the crass mechanism of Descartes. Henri Bergson (1859-1941) and Hans Driesch (1867-1941) were prominent vitalists in the early twentieth century. The end of vitalism came when it no longer could find any supporters. Two causes were largely responsible for this: first, the failure of literally thousands of unsuccessful experiments conducted to demonstrate the existence of a Lebenskraft; second, the realization that the new biology, with the methods of genetics and molecular biology, was able to solve all the problems for which scientists traditionally had invoked the Lebenskraft. In other words, the proposal of a Lebenskraft had simply become unnecessary.
It would be ahistorical to ridicule vitalism. When one reads the writings of some of the leading vitalists, like Driesch, one is forced to agree with him that many of the basic problems of biology simply cannot be solved by Cartesian philosophy, in which the organism is considered nothing but a machine. The developmental biologists, in particular, asked some very challenging questions. For example, how can a machine regenerate lost parts, as many kinds of organisms are able to do? How can a machine replicate itself? How can two machines fuse into a single one like the fusion of two gametes to produce a zygote? The critical logic of the vitalists was impeccable. But all their efforts to find a scientific answer to the so-called vitalistic phenomena were failures. Generations of vitalists labored in vain to find a scientific explanation for the Lebenskraft until it finally became quite clear that such a force simply does not exist. That was the end of vitalism.

TELEOLOGY Teleology is the second invalid principle that had to be eliminated from biology before it qualified as a science equivalent to physics. Teleology deals with the explanation of natural processes that seem to lead automat- ically to a definite end or goal. To explain the development of the fertilized egg to the adult of a given species, Aristotle invoked a fourth cause, the causa finalis. Eventually, one invoked this cause for all phenomena in the cosmos that led to an end or goal. Kant in his Critique of Judgment at first tried to explain the biological world in terms of Newtonian natural laws but was completely unsuccessful in this endeavor. Frustrated he ascribed all Zweckmässigkeit (adaptedness) to teleology. This was, of course, no solution. A widely supported school of evolutionists, for instance, the

MAYR / THE AUTONOMY OF BIOLOGY / 17
so-called orthogenesists, invoked teleology to explain all progressive evo- lutionary phenomena. They believed that in living nature there is an intrinsic striving (“orthogenesis”) toward perfection. Here belongs also Lamarck’s theory of evolution, and orthogenesis had many followers before the Evolutionary Synthesis. Alas, no evidence for the existence of such a teleological principle could ever be found and the discoveries of genetics and paleontology eventually totally discredited cosmic teleology. For a more detailed discussion of teleology see Mayr (1992).
WHAT IS BIOLOGY? When we try to answer this question, we find that biology actually consists of two rather different fields, mechanistic (functional) biology and histori- cal biology. Functional biology deals with the physiology of all activities of living organisms, particularly with all cellular processes, including those of the genome. These functional processes ultimately can be explained
purely mechanistically by chemistry and physics.

The other branch of biology is historical biology. A knowledge of history
is not needed for the explanation of a purely functional process. However, it is indispensable for the explanation of all aspects of the living world that involve the dimension of historical time—in other words, as we now know, all aspects dealing with evolution. This field is evolutionary biology.
The two fields of biology also differ in the nature of the most frequently asked questions. To be sure in both fields one asks “what?” questions to get the facts needed for further analysis. The most frequently asked question in functional biology, however, is “how?”; in evolutionary biol- ogy “why?” is the most frequently asked question. This difference is not complete because in evolutionary biology one also occasionally asks “how” questions—for instance, how do species multiply? Anyhow, as we will see, to obtain its answers, particularly in cases in which experiments are inappropriate, evolutionary biology has developed its own methodology, that of historical narratives (tentative scenarios).
To truly appreciate the nature of biology one must know the remarkable difference between these two branches of biology. Indeed, some of the most decisive differences between the physical sciences and biology are true for only one of these branches, for evolutionary biology.
THE EMERGENCE OF MODERN BIOLOGY The two-hundred-year period from about 1730 to 1930, witnessed a radical change in the conceptual framework of biology. The period from1828 to 1866 was particularly innovative. Within these 38 years, both branches of modern biology—functional and evolutionary biology—were estab- lished. Yet biology was still largely ignored by the philosophers of science,

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from Carnap, Hempel, Nagel, and Popper to Kuhn. Biologists, even though they now rejected vitalism and cosmic teleology, were unhappy with a purely mechanistic (Cartesian) philosophy of biology. But all en- deavors to escape from this dilemma—such as, for example, the writings of Jonas, Porcmann, von Uexküll, and several others—invariably invoked some nonmechanical forces that were not acceptable to most biologists. The solution had to satisfy two demands: it had to be completely compat- ible with the natural laws of the physicists, and no solution was acceptable that would invoke any occult forces. It was not until almost the middle of the twentieth century that it became evident that a solution could not be found by a philosopher who did not have a background in biology. But no such philosopher made the attempt.

It turned out that to develop an autonomous science of biology one had to do two further things. First, one had to undertake a critical analysis of the conceptual framework of the physical sciences. This revealed that some of the basic principles of the physical sciences are simply not appli- cable to biology. They had to be eliminated and replaced by principles pertinent to biology. Second, it was necessary to investigate whether biology is based on certain additional principles that are inapplicable to inanimate matter. This required a restructuring of the conceptual world of science that was far more fundamental than anyone had imagined at that time. It became apparent that the publication in 1859 of Darwin’s Origin of Species was really the beginning of an intellectual revolution that ultimately resulted in the establishment of biology as an autonomous science.

PHYSICALIST IDEAS NOT APPLICABLE TO BIOLOGY Darwin’s ideas were particularly important in the discovery that a number of basic concepts of the physical sciences, which up to the middle of the nineteenth century were also widely held by most biologists, are not applicable to biology. I will now discuss four of these basic physicalist concepts for which it had to be demonstrated that they are not applicable to biology before it was realized how different biology is from the physical
sciences.

1. ESSENTIALISM (TYPOLOGY). From the Pythagoreans and Plato on, the
traditional concept of the diversity of the world was that it consisted of a limited number of sharply delimited and unchanging eide or essences. This viewpoint was called typology or essentialism. The seemingly endless variety of phenomena, it was said, actually consisted of a limited number of natural kinds (essences or types), each forming a class. The members of each class were thought to be identical, constant, and sharply separated from the members of any other essence. Therefore, variation was nones- sential and accidental. The essentialists illustrated this concept by the

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example of the triangle. All triangles have the same fundamental charac- teristics and are sharply delimited against quadrangles or any other geo- metric figure. An intermediate between a triangle and a quadrangle is inconceivable.
Typological thinking, therefore, is unable to accommodate variation and has given rise to a misleading conception of human races. Caucasians, Africans, Asians, and Inuits are types for a typologist that differ conspicu- ously from other human ethnic groups and are sharply separated from them. This mode of thinking leads to racism. Darwin completely rejected typological thinking and instead used an entirely different concept, now called population thinking.

2. DETERMINISM. One of the consequences of the acceptance of determi- nistic Newtonian laws was that it left no room for variation or chance events. The famous French mathematician and physicist Laplace boasted that a complete knowledge of the current world and all its processes would enable him to predict the future to infinity. Even the physicists soon discovered the occurrence of enough randomness and contingencies to refute the validity of Laplace’s boast. The refutation of strict determinism and of the possibility of absolute prediction freed the way for the study of variation and of chance phenomena, so important in biology.

3. REDUCTIONISM. Most physicalists were reductionists. They claimed that the problem of the explanation of a system was resolved in principle as soon as the system had been reduced to its smallest components. As soon as one had completed the inventory of these components and had determined the function of each one of them, they claimed, it would be an easy task also to explain everything observed at the higher levels of organization.

4. THE ABSENCE OF UNIVERSAL NATURAL LAWS IN BIOLOGY. The philoso- phers of logical positivism, and indeed all philosophers with a background in physics and mathematics, base their theories on natural laws, and such theories are therefore usually strictly deterministic. In biology there are also regularities, but various authors (Smart 1963, Beatty 1995) severely question whether these are the same as the natural laws of the physical sciences. There is no consensus yet in the answer to this controversy. Laws certainly play a rather small role in theory construction in biology. The major reason for the lesser importance of laws in biological theory forma- tion is perhaps the greater role played in biological systems by chance and randomness. Other reasons for the small role of laws are the uniqueness of a high percentage of phenomena in living systems as well as the historical nature of events.
Owing to the probabilistic nature of most generalizations in evolution- ary biology, it is impossible to apply Popper’s method of falsification for theory testing because a particular case of a seeming refutation of a certain

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law may not be anything but an exception, as are common in biology. Most theories in biology are based not on laws but on concepts. Examples of such concepts are, for instance, selection, speciation, phylogeny, compe- tition, population, imprinting, adaptedness, biodiversity, development, ecosystem, and function.
The inapplicability to biology of these four principles that are so basic in the physical sciences has contributed a great deal to the insight that biology is not the same as physics. To get rid of these inappropriate ideas was the first, and perhaps the hardest, step in developing a sound philoso- phy of biology.

AUTONOMOUS CHARACTERISTICS OF BIOLOGY The last step in the development of the autonomy of biology was the
discovery of a number of biology-specific concepts or principles.
THE COMPLEXITY OF LIVING SYSTEMS There are no inanimate systems in the mesocosmos that are even any- where near as complex as the biological systems of the macromolecules and cells. These systems are rich in emergent properties because forever new groups of properties emerge at every level of integration. An analysis contributes nearly always to a better understanding of these systems, even though reduction in the strict sense of the word is impossible. Biological systems are open systems; the principles of entropy therefore are not applicable. Owing to their complexity, biological systems are richly en- dowed with capacities such as reproduction, metabolism, replication, regulation, adaptedness, growth, and hierarchical organization. Nothing
of the sort exists in the inanimate world.

Another biology-specific concept is that of evolution. To be sure, even
before Darwin geologists knew about changes on the Earth’s surface and cosmologists were aware of the probability of changes in the universe, particularly in the solar system. However, on the whole, the world was seen as something quite constant, something that had not changed since the day of Creation. This view totally changed after the middle of the nineteenth century when science became aware of the comprehensive- ness of the evolution of the living world.
The adoption of the concept of the biopopulation is responsible for what now seems probably the most fundamental difference between the inani- mate and the living world. The inanimate world consists of Plato’s classes, essences and types, with the members of each class being identical, and with the seeming variation being “accidental” and therefore irrelevant. In a biopopulation, by contrast, every individual is unique, while the statis- tical mean value of a population is an abstraction. No two of the six billion humans are the same. Populations as a whole do not differ by their

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essences but only by statistical mean values. The properties of populations change from generation to generation in a gradual manner. To think of the living world as a set of forever variable populations grading into each other from generation to generation results in a concept of the world that is totally different from that of a typologist. The Newtonian framework of unalterable laws predisposes the physicist to be a typologist, seemingly almost as if by necessity. Darwin introduced population thinking into biology rather casually, and it took a long time before it was realized that this is an entirely different concept from the typological thinking tradi- tional in the physical sciences (Mayr 1959).
Population thinking and populations are not laws but concepts. It is one of the most fundamental differences between biology and the so-called exact sciences that in biology theories usually are based on concepts while in the physical sciences they are based on natural laws. Examples of concepts that became important bases of theories in various branches of biology are territory, female choice, sexual selection, resource, and geographic isola- tion. And even though, by means of appropriate rewording, some of these concepts can be phrased as laws, they are something entirely different from the Newtonian natural laws.

Furthermore, all biological processes differ in one respect fundamen- tally from all processes in the inanimate world: they are subject to dual causation. In contrast to purely physical processes, these biological ones are controlled not only by natural laws but also by genetic programs. This duality fully provides a clear demarcation between inanimate and living processes.
The dual causality, however, which is perhaps the most important diagnostic characteristic of biology, is a property of both branches of biology. When I speak of dual causality I am of course not referring to Descartes’ distinction of body and soul but rather to the remarkable fact that all living processes obey two causalities. One of them is the natural laws that, together with chance, control completely everything that hap- pens in the world of the exact sciences. The other causality consists of the generic programs that characterize the living world so uniquely. There is not a single phenomenon or a single process in the living world that is not in part controlled by a genetic program contained in the genome. There is not a single activity of any organism that is not affected by such a program. There is nothing comparable to this in the inanimate world. Dual causation, however, is not the only unique property of biology to support the thesis of the autonomy of biology. Indeed it is reinforced by some six or seven additional concepts. I will now discuss some of these.
The most novel and most important concept introduced by Darwin was perhaps that of natural selection. Natural selection is a process that is both so simple and so convincing, that it is almost a puzzle why after 1858 it

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took almost eighty years before it was universally adopted by evolution- ists. To be sure, the process has been somewhat modified in the course of time. It is rather a shock for some biologists to learn that natural selection, taken strictly, is not a selection process at all, but rather a process of elimination and differential reproduction. It is the least adapted individu- als that in every generation are eliminated first, while those that are better adapted have a greater chance to survive and reproduce.
There has long been a great deal of argument about what is more important, variation or selection? But there is no argument. The produc- tion of variation and true selection are inseparable parts of a single process. At the first step, variation is produced by mutation, recombination, and environmental effects, and at the second step the varying phenotypes are sorted by selection. Of course, during sexual selection real selection takes place. Natural selection is the driving force of organic evolution and represents a process quite unknown in inanimate nature. This process enabled Darwin to explain the “design” so important in the arguments of the natural theologians. The fact that all organisms are seemingly so perfectly adapted to each other and to their environment was attributed by the natural theologians to God’s perfect design. Darwin, however, showed that it could be equally well, indeed even better, explained by natural selection. This was the decisive refutation of the principle of cosmic teleology.

EVOLUTIONARY BIOLOGY IS A HISTORICAL SCIENCE It is very different from the exact sciences in its conceptual framework and methodology. It deals, to a large extent, with unique phenomena, such as the extinction of the dinosaurs, the origin of humans, the origin of evolu- tionary novelties, the explanation of evolutionary trends and rates, and the explanation of organic diversity. There is no way to explain these phenomena by laws. Evolutionary biology tries to find the answer to “why?” questions. Experiments are usually inappropriate for obtaining answers to evolutionary questions. We cannot experiment about the extinction of the dinosaurs or the origin of mankind. With the experiment unavailable for research in historical biology, a remarkable new heuristic method has been introduced, that of historical narratives. Just as in much of theory formation, the scientist starts with a conjecture and thoroughly tests it for its validity, so in evolutionary biology the scientist constructs a historical narrative, which is then tested for its explanatory value.
Let me illustrate this method by applying it to the extinction of the dinosaurs, which occurred at the end of the Cretaceous, about sixty-five million years ago. An early explanatory narrative suggested that they had become the victims of a particularly virulent epidemic against which they had been unable to acquire immunity. However, a number of serious

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objections were raised against this scenario, which was therefore replaced by a new proposal, according to which the extinction had been caused by a climactic catastrophe. Yet, neither climatologists nor geologists were able to find any evidence for such a climatic event and this hypothesis also had to be abandoned. Then, when the physicist Walter Alvarez postulated that the extinction of the dinosaurs had been caused by the consequences of an asteroid impact on earth, all observations fitted this new scenario. The discovery of the impact crater in Yucatan further strengthened the Alvarez theory. No subsequent observations were in conflict with this theory.
The methodology of historical narratives is clearly a methodology of historical sciences. Indeed, evolutionary biology, as a science, in many respects is more similar to the Geisteswissenschaften, than to the exact sciences. When drawing the borderline between the exact sciences and the Geisteswissenschaften, this line would go right through the middle of biol- ogy and attach functional biology to the exact sciences while classifying evolutionary biology with the Geisteswissenschaften. This, incidentally, shows the weakness of the old classification of the sciences, which was made by philosophers familiar with the physical sciences and the humani- ties but ignorant of the existence of biology.

Observation plays as important a role in the physical as in the biological sciences. The experiment is the most frequently used methodology in the physical sciences and in functional biology, while in evolutionary biology the testing of historical narratives and the comparison of a variety of evidence are the most important methods. This methodology is used in the physicalist sciences only in some historical disciplines such as geology and cosmology. The important role of historical narratives in the historical sciences has been almost entirely ignored by philosophers up to now. It is important to point out that comparison is perhaps an even more important and more frequently applied methodology in the biological sciences, from comparative anatomy and comparative physiology to comparative psy- chology, than in the method of historical narratives. This is also true for molecular biology because comparison is indispensable in most researches in this field. Indeed, much of genomics consists of the comparison of base pair sequences.
CHANCE The natural laws usually effect a rather deterministic outcome in the physical sciences. Neither natural nor sexual selection guarantees such determinism. Indeed, the outcome of an evolutionary process is usually the result of an interaction of numerous incidental factors. Chance with respect to functional and adaptive outcome is rampant in the production of variation. During meiosis, in the reduction division it governs both crossing-over and the movement of chromosomes. Curiously, it was this

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chance aspect of natural selection for which this theory was most often criticized. Some of Darwin’s contemporaries, for instance the geologist Adam Sedgwick, declared that invoking chance in any explanation was unscientific. Actually, it is precisely the chanciness of variation that is so characteristic of Darwinian evolution. Even today there is still much argument about the role of chance in the evolutionary process. Selection, of course, always has the last word.

HOLISTIC THINKING Reductionism is the declared philosophy of the physicalists. Reduce everything to the smallest pares, determine the properties of these parts, and you have explained the whole system. However, in a biological system there are so many interactions among the parts—for instance, among the genes of the genotype—that a complete knowledge of the properties of the smallest parts gives necessarily only a partial explanation. Nothing is as characteristic of biological processes as interactions at all levels, among genes of the genotype, between genes and tissues, between cells and other components of the organism, between the organism and its inanimate environment and between different organisms. It is precisely this interac- tion of parts that gives nature as a whole, or the ecosystem, or the social group, or the organs of a single organism, its most pronounced charac- teristics. Rejecting the philosophy of reductionism is not an attack on analysis. No complex system can be understood except through careful analysis. However, the interactions of the components must be considered as much as the properties of the isolated components. How the smaller units are organized into larger units is critically important for the particu- lar properties of the larger units. This aspect of organization and the

resulting emergent properties are what the reductionists had neglected.
LIMITATION TO THE MESOCOSMOS As far as their accessibility to the human sense organs is concerned, one can distinguish three worlds. One is the microcosmos or the subatomic world of elementary particles and their combinations, the second is the meso- cosmos extending from atoms to galaxies, and the third is the macrocos- mos, the world of cosmic dimensions. On the whole, only the mesocosmos is relevant to biology, even though in cellular physiology electrons and protons are sometimes involved. To the best of my knowledge, none of the great discoveries made by physics in the twentieth century has con-
tributed anything to an understanding of the living world.
Observation and comparison are highly important methods also in the humanities, and therefore biology functions as an important bridge be- tween the physicalist sciences and the humanities. The foundation of a philosophy of biology is particularly important for the explanation of mind and consciousness. Evolutionary biology has revealed that in such

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explanations there is no fundamental difference between humans and animals. Evolutionary thinking and the recognition of the role of chance and of uniqueness are now also appreciated in the humanities.
This explains why all earlier endeavors to construct a philosophy of biology within the conceptual framework of the physical sciences were such failures. Biology, we now realize, is indeed largely an autonomous science and a philosophy of biology must be based primarily on the peculiar characteristics of the living world, recognizing at the same time that this is not in conflict with a strictly physicochemical explanation at the cellular-molecular level 1.

CAN AN AUTONOMOUS BIOLOGY BE UNIFIED WITH PHYSICS? In the two hundred years after Galileo there was a unified science; it was physics. There was no biology to cause problems. But the comforting belief in a unified science became increasingly more difficult to uphold with the rise of biology. This difficulty was widely appreciated and whole organi- zations were founded to undertake a unification of science. The way to accomplish this was through reduction. This view was based on the convic- tion that all tangible phenomena of this world “are based on material processes that are ultimately reducible ... to be laws of physics” (Wilson 1998, p. 266). But this suggestion was based on a faulty analysis of biology, neglecting its autonomous components. Such a reduction would be pos- sible only if all of the theories of biology could be reduced to the theories of physics and molecular biology, but this is impossible. Wilson thought consilience was a mechanism that would make such reduction possible. Indeed he claimed “consilience is the key to unification” (1998, p. 8) and “consilience is to be achieved by reduction to the laws of physics.” This is a beautiful dream but none of the autonomous features of biology can possibly be unified with any of the laws of physics. The endeavor of a unification of the sciences is a search for a Fata Morgana. As is said in the
vernacular, “you cannot unify apples with oranges.”

This conclusion is so important because it has numerous consequences.
One of them is that one cannot base a philosophy of biology on the concep- tual framework of the physical sciences. Nor can a philosophy of biology be expressed by the explanations of a single branch of biology, let us say molecular biology. Instead, it must be based on the facts and fundamental concepts of the entire living world, as was presented in this paper.
We need a similar analysis of all other sciences and this will permit us to determine what the various sciences have in common. But such analy- ses, as presented in this paper for biology, have not yet been undertaken for any of the other sciences.

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THE IMPORTANCE OF BIOLOGY FOR THE UNDERSTANDING OF HUMANS
Until 1859, there was almost complete consensus that humans are funda- mentally different from the remainder of creation. Theologians, philoso- phers, and scientists completely agreed with each other on this point. Darwin’s theory of the descent of all species from common ancestors and its application to humans resulted in a fundamental change. One then realized that the human species is a member of the ape family and is, as such, a legitimate object of scientific research. The consequences of this new insight can be seen in the modern developments of anthropology, behavioral biology, cognitive psychology, and sociobiology.

What was perhaps the most shocking finding was how incredibly similar the human genome is to that of the chimpanzee (Diamond 1992). But precisely the comparison with the chimpanzee has led to a better understanding of humans. For instance, it could no longer be denied that many humans have an inborn tendency for strongly aggressive behavior after one discovered that chimpanzees may also show similar aggressive behavior. Yet, altruism also occurs widely among primates (de Waal 1997) and this ancestry facilitates an understanding of human altruism. Com- parisons with primates have revealed that it is entirely justified to inves- tigate humans with the same methods used with animals. Part of the philosophy of humans can therefore by merged with biophilosophy.

ACKNOWLEDGMENT
The text of this article will appear, with slight modifications, in Ernst Mayr (2004), What Makes Biology Unique? New York and Cambridge: Cambridge University Press, pp. 21-38.

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NOTE
1 For a review of some of the controversies between supporters and opponents of the autonomy of biology, see Mayr (1996).
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Δευτέρα, 30 Ιουλίου 2012

Walter Arndt Lecture: The Autonomy of Biology Ernst Mayr





Science as we know it is the product of developments in the 17th and 18th centuries. What was conceived as science is indicated by the names Galileo, Kepler, Newton, Descartes, and Leibniz. It was the glorious rise of the physical sciences advancing from triumph to triumph. It was physics what people meant when they talked about science, biology was never included. The science of biology was a creation of the l9th century. Of course, there were branches of medicine such as anatomy, physiology, and embryology that we now include in biology but they were concerned with healing and were not considered to be the part of a separate science of biology. At the same time there was also a flourishing pursuit of natural history under the label of Natural Theology. A genuine biology remained dormant until the 19th century.

It took more than two hundred years and the occurrence of three different sets of events before a genuine science of biology originated. One can assign these events to three different sets: (A) the refutation of certain erroneous principles, (B) the demonstration that certain basic principles of physics cannot be applied to biology, and (C) the realization of the uniqueness of certain basic principles of biology that are not found in the inanimate world. Let us now review these three sets of events.
A: The refutation of certain erroneous basic assumptions.

Under this heading I deal with the support for certain basic ontological principles which later were shown to be erroneous. Biology could not be recognized as a science of the same rank as physics as long as most biologists accepted certain basic explanatory principles not supported by the laws of the physical sciences and eventually found to be invalid. The two major principles here involved are vitalism and a belief in cosmic teleology. As soon as it had been demonstrated that these two principles are invalid and, more broadly, that none of the phenomena of the living world are in conflict with the natural laws of the physicalists, there was no longer any reason for not recognizing biology as a legitimate autonomous science, equivalent to physics.

Vitalism

The nature of life, the property of being living, has always been a puzzle for the philosophers. Descartes tried to solve it by simply ignoring it. An organism is really nothing but a machine, he said. And other philosophers, particularly such with a background in mathematics, logic, physics, and chemistry, tended to follow him and operated as if there was no difference between living and inanimate matter. But this did not satisfy most naturalists. They were convinced that in a living organism certain forces are active which do not exist in inanimate nature. They concluded that just as the motion of planets, suns, and stars, is controlled by an occult, invisible force called by Newton gravitation, analogously the movements and other manifestations of life in organisms is controlled by an invisible force, Lebenskraft orvis vitalis. Those who believed in such a force were called vitalists.
Vitalism was popular from the early 17th century to the early 20th century. It was a natural reaction to the crass mechanism of Descartes. Henri Bergson and Hans Driesch were prominent vitalists in the early 20th century. The end of vitalism came when it could no longer find any supporters. Two causes were largely responsible for this, first the failure of literally thousands of failed experiments conducted to prove the existence of a Lebenskraft, and secondly, the realization that the new biology, with the methods of genetics and molecular biology, was able to solve all the problems for which one traditionally had invoked the Lebenskraft. In other words the proposal of a Lebenskraft had simply become unnecessary.

It would be ahistorical to ridicule vitalists. When one reads the writings of one of the leading vitalists like Driesch one is forced to agree with him that many of the basic problems of biology simply cannot be solved by a philosophy as that of Descartes, in which the organism is simply considered a machine. The developmental biologists in particular asked some very challenging questions. For exarnple, how can a machine regenerate lost parts, as many kinds of organisms are able to do? How can a machine replicate itself ? How can two machines fuse into a single one like the fusion of two gametes when producing a zygote ?

The logic of the critique of the vitalists was impeccable. But all their efforts to find a scientific answer to all the so-called vitalistic phenomena were failures. Generations of vitalists labored in vain to find a scientific explanation for the Lebenskraft until it finally became quite clear that such a force simply does not exist.

Teleology.

Teleology is the second invalid principle which had to be eliminated from biology before it qualified as a science equivalent to physics. Teleology deals with the explanation of natural processes which automatically seem to lead to a definite end or goal. To explain the development of the fertilized egg to the adult of a given species Aristotle invoked a fourth cause, the causa finalis. Eventually one invoked this cause for all phenomena in the cosmos which led to an end or goal. Kant in his Critique of Judgment had tried to explain the biological world in terms of Newtonian natural laws but had been completely unsuccessful in this endeavor. Frustrated he ascribed all Zweckmässigkeit as being due to teleology. This was, of course, no solution. A widely-supported school of evolutionists, for instance the so-called orthogenesists, invoked teleology to explain all progressive evolutionary phenomena. They believed that in living nature there is an intrinsic strive toward perfection. Here belongs also Lamarck's theory of evolution and orthogenesis had many followers prior to the evolutionary synthesis. Alas, no evidence for the existence of such a teleological principle could ever be found and the discoveries of genetics and paleontology eventually totally discredited cosmic teleology. The distinguished philosopher Quine told me once that he considered it as Darwin's greatest achievement to have refuted Aristotle's fourth cause by showing that the attainment of a definite goal in evolution could be explained by natural selection. There are numerous seemingly goal-directed processes in nature, particularly in biology, which one now no longer explains by occult teleological forces but by scientifically supported chemical-physical factors. I distinguish four groups of such factors which formerly had been referred to as teleological (Mayr 1992, 1998). The fifth group of factors, attributed to an intrinsic potential of the cosrnos to cause goal direction, could never be substantiated. Such cosmic teleology is now considered not to exist.

What is biology ?

When we investigate this we find that biology actually consists of two rather different fields, functional biology and historical biology. Functional biology deals with the physiology of all activities of living organisms, particularly with all cellular processes, including those of the genome. These functional processes can be explained by chemistry and physics.
The other branch of biology is historical biology. A knowledge of history is not needed for the explanation of a purely functional process. It is however all-important for the explanation of all aspects of the living world that involve the dimension of historical time, in other words, as we now know, all aspects dealing with evolution.

The two fields of biology also differ in the nature of the most frequently asked questions. To be sure in both fields one asks what? questions, in order to get the facts needed for further analysis. The most frequently asked question in functional biology, however, is how?, while in evolutionary biology it is why? This difference is not complete because in evolutionary biology one also asks occasionally how? questions, for instance how do species multiply ? However, as we will see, evolutionary biology has developed its own methodology, that of historical narratives, to obtain its answers, particularly in cases where experiments are inappropriate.

In order to truly appreciate the autonomy of biology one must know the remarkable difference between these two branches of biology. Indeed some of the most decisive differences between the physical sciences and biology are true for only one of these branches, for evolutionary biology.
The emergence of modern biology.

The two hundred year period, from ca. 1730 to 1930, witnessed a radical change in the conceptual framework of biology. It included the period from 1828 to 1866 during which both branches of modern biology, functional and evolutionary biology, were established, which resulted in the eventual refutation of vitalism and cosmic teleology. Yet biology was still largely ignored by the philosophers of science from Carnap, Hempel, Nagel, Popper, to Kuhn. The biologists, even though they now rejected vitalism and cosmic teleology, were unhappy with a purely mechanistic philosophy of biology. But all endeavors to escape from this dilemma, such as for example the writings of Jonas, Portmann, Uexküll, and several others, invariably invoked some non-mechanical forces. It was not until almost the middle of the 20th century until it became evident that a solution could not be found by a philosopher who did not have a background in biology. At the same time it became equally clear that, however the solution would be, it had to be completely compatible with the natural laws. No solution was acceptable that would invoke any occult forces. But how could such a solution be found ?

It turned out that in order to develop an autonomous science of biology one had to do two further things. First, undertake a critical analysis of the conceptual framework of the physical sciences. This revealed that some of the basic principles of the physical sciences are simply not applicable to biology. They had to be eliminated and replaced by principles pertinent to biology. And secondly, it was necessary to investigate whether biology is based among others on certain additional principles that are inapplicable to inanimate matter. This required a restructuring of the conceptual world of science that was far more fundamental than anyone had imagined at that time. lt became apparent that the publication in 1859 of Darwin's Origin of Species was really the beginning of an intellectual revolution that ultimately resulted in the establishment of the autonomy of biology.

B. Physicalist ideas not applicable to biology.

Darwin's ideas were particularly important in the discovery that a number of basic concepts of the physical sciences, which up to the middle of the 19th century were also widely held by most biologists, are not applicable to biology. I will now discuss four of these basic physicalist concepts for which it had to be demonstrated that they are not applicable to biology, before it was realized how different biology is from the physical sciences.

1. Essentialism.

From the Pythagoreans and Plato on the traditional concept of the diversity of the world was that it consisted of a limited number of sharply delimited and unchanging eide or essences. This viewpoint was called typology or essentialism. The seemingly endless variety of phenomena, it was said, actually consisted of a limited number of natural kinds (essences or types) each forming a class. The members of each class were thought to be identical, constant, and sharply separated from the members of any other essence. Therefore, variation was nonessential and accidental. The essentialists illustrated this concept by the example of the triangle. All triangles have the same fundamental characteristics and are sharply delimited against quadrangles or any other geometric figure. An intermediate between a triangle and a quadrangle is inconceivable.

Typological thinking, therefore, is unable to accommodate variation and has given rise to a misleading conception of human races. Caucasians, Africans, Asians, or Inuits are types for a typologist that conspicuously differ from other human ethnic groups and are sharply separated from them. This mode of thinking leads to racism. Darwin completely rejected typological thinking and used instead an entirely different concept, now called population thinking (see below).

2. Determinism.

One of the consequences of the acceptance of deterministic Newtonian laws was that it left no room for variation or chance events. The famous French mathematician and physicist Laplade boasted that a complete knowledge of the current world and all its processes would enable him to predict the future to infinity. Even the physicists soon discovered the occurrence of enough randomness and contingencies to refute the validity of Laplace's boast. The refutation of strict determinism and of the possibility of absolute prediction freed the way for the study of variation and of chance phenomena, so important in biology.

3. Reductionism.

Most physicalists were reductionists. They claimed that the problem of the explanation of a system was resolved in principle as soon as the system had been reduced to its smallest components. As soon as one had completed the inventory of these components and had determined thc function of each one of them, they claimed it would be an easy task to explain also everything observed at the higher levels of organization. This claim was vigorously objected to by biologists already more than one hundred years ago. Darwin's friend T. H. Huxley asked the reductionists why the reduction of water (H2O) to hydrogen gas and oxygen gas did not explain the nature of water ? What the reductionists confused was reduction and analysis. Of course we learn a great deal about any complex system by analyzing it. Indeed analysis is a most important and heuristic method in all branches of science, including biology. But first of all, in many cases of analysis, one does not have to go anywhere near the smallest parts (electrons, protons, etc...). Furthermore, and this is what the reductionists usually overlooked, in order to understand a system one needs to know not only the properties of its components but also the nature of the interactions among these components. And it is precisely these interactions that are so important in living systems. Their study is the objective of the holists (see below).

4. Laws.

All theories in the physical sciences are based on natural laws. Normally they have no exceptions which led Popper to the claim that any exception to a theory amounted to its falsification. Indeed, on the whole, properly articulated laws are the basis of the theory structure of the physical sciences. But is this also true for biology ? This has been seriously questioned by a number of philosophers (Smart 1963, Beatty 1995) and only few biological theories are based on laws. They are usually rather based on concepts, as we shall presently see.

The inapplicability of these four principles that are so basic in the physical sciences, has contributed a great deal to the insight that biology is not the same as physics. To get rid of these erroneous ideas was the first but perhaps hardest step in developing a sound philosophy of biology.

C. Autonomous characteristics of biology.

The last step in the development of the autonomy of biology was the discovery of a number of biology-specific concepts or principles. One is the concept of evolution. To be sure even before Darwin geologists knew about changes on the Earth's surface and cosmologists were aware of the probability of changes in the universe, particularly in the solar system. However, the world was seen as something quite constant, something that had not changed since the day of Creation. This view totally changed after the middle of the 19th century when science became aware of the comprehensiveness of the evolution ofthe living world.

The adoption of the concept of the biopopulation is responsible for what now seems probably the most fundamental difference between the inanimate and the living world. The inanimate world consists of Platonian classes, essences, types, with the members of each class being identical, and with the seeming variation being "accidental" and therefore irrelevant. In a biopopulation, by contrast, every individual is unique, while the statistical mean value of a population is an abstraction. No two of the six billion humans are the same. Populations as a whole do not differ by their essences but only by mean statistical values. The properties of populations change from generation to generation in a gradual manner. To think of the living world as a set of forever variable populations grading into each other from generation to generation, results in a concept of the world that is totally different from that of a typologist. The Newtonian framework of unalterable laws predisposes a physicist to be a typologist, seemingly almost as if by necessity. Darwin introduced population thinking into biology rather casually, and it took a long time before it was being realized that this is an entirely different concept from the typological thinking traditional in the physical sciences (Mayr 1959).

Population thinking and populations are not laws but concepts. It is one of the most fundamental differences between biology and the so-called exact sciences that in biology theories are usually based on concepts while in the physical sciences they are based on natural laws. Examples of concepts that became important bases of theories in various branches of biology are territory, female choice, sexual selection, resource, and geographic isolation. And even though, through appropriate rewording, some of these concepts can be phrased as laws, they are something entirely different from the Newtonian natural laws.

All biological processes differ in one respect fundamentally from all processes in the inanimate world; they are subject to dual causation. In contrast to purely physical processes these biological ones are controlled not only by natural laws but also by genctic programs. This duality fully provides a clear demarcation between inanimate and living processes.

The dual causality, however, which is perhaps the most important characteristic of biology by which it differs indubitably from the physical sciences, is a property of both areas of biology. When I speak of dual causality I am of course not referring to Descartes' distinction of body and soul but rather to the remarkable fact that all living processes obey two causalities. One of them are the natural laws which, together with chance, control completely everything that happens in the world of the exact sciences. The other causality consists of the genetic programs which characterize the living world so uniquely. There is not a single phenomenon or a single process in the living world which is not controlled by a genetic program contained in the genome. There is not a single activity of any organism that is not controlled by such a program. There is nothing comparable in the inanimate world. Dual causation, however, is not the only unique property of biology to support the thesis of the autonomy of biology. Indeed it is reinforced by some six or seven additional concepts. I will now discuss some of these.

The most novel and most important concept introduced by Darwin was perhaps that of natural selection. Natural selection is a process that is both so simple and so convincing, that it is almost a puzzle why after 1858 it took almost 80 years before it was universally adopted by evolutionists. To be sure, the process has been somewhat modified in the course of years. It is rather a shock for some biologists to learn that natural selection, taken strictly, is not a selection process at all, but rather a process of elimination. It is the least well adapted individuals that are eliminated in every generation, and those that are better adapted have a greater chance to survive. Also, in recent years, there has been a great deal of argument, what was more important, variation or selection. For me, there is no argument. The production of variation and true selection are for me inseparable parts of a single process. At the first step variation is produced by mutation and recombination, and at the second step the variants are sorted by selection. Of course, during sexual selection real selection takes place. Natural selection is the driving force of organic evolution and represents a process quite unknown in inanimate nature. 

This process enabled Darwin to explain the "design" so important in the arguments of the natural theologians. The fact that all organisms are seemingly so perfectly adapted to each other and to their environment was attributed by the natural theologians to God's perfect design. Darwin however showed that it could be equally well, indeed even better, explained by natural selection. Before and even after the publication of the Origin, it was widely postulated that God had given Nature the capacity to move toward perfection. Indeed many natural processes seem to move toward a final goal such as the fertilized egg toward the adult stage. Aristotle had referred to this as the "final cause", later philosophers had called it teleology.

Evolutionary biology is a historical science. It is very different from the exact sciences in its conceptual framework and methodology. It deals, to a large extent, with unique phenomena, such as the extinction of the dinosaurs, the origin of man, the origin of evolutionary novelties, the explanation of evolutionary trends and rates, and the explanation of organic diversity. Evolutionary biology tries to find the answer to why questions. Experiments are usually inappropriate for obtaining answers to evolutionary questions. We cannot experiment about the extinction of the dinosaurs or the origin of mankind. There is, however, a remarkably heuristic method available, that of historical narratives. Just as in much of theory formation you start with a conjecture which you thoroughly test for its validity, so in evolutionary biology you construct a scenario, a historical narrative, which you test for its explanatory value. Let us take the case of the extinction of the dinosaurs. 

An early conjecture was that they had been the victims of a devastating viral or bacterial epidemic. For various reasons this narrative was not very credible. A second scenario suggested that a drastic climatic event had led to the mass extinction. Geologists however could find no evidence for a drastic, climatic change. Eventually the physicist Alvarez suggested that the Earth had been hit by an asteroid which had kicked up such a large amount of dust that for a short time it had made life on Earth very precarious. The dinosaurs became extinct but a few probably nocturnal and small mammals had been lucky to survive. The impact crater of the postulated asteroid was eventually found near the Yucatan peninsula in Mexico and all other recent findings since have confirmed the impact theory to such an extent that it is now quite generally accepted.

The methodology of historical narratives is clearly a methodology of historical science. Indeed evolutionary biology as a science, is in many respects more similar to the Geisteswissenschaften than to the exact sciences. When drawing the borderline between the exact sciences and the Geisteswissenschaften it would go right through biology and attach functional biology to the exact sciences while including evolutionary biology with the Geisteswissenschaften. This, incidentally, shows the weakness of the old classification of the sciences. That classification was made by philosophers familiar with the physical sciences and the humanities but completely ignorant of the existence of biology.

Chance.

The natural laws usually effect a rather deterministic outcome in the physical sciences. Neither natural nor sexual selection guarantee such determinism. Indeed the outcome of an evolutionary process is usually the result of an interaction of numerous incidental factors. Chance is also rampant in the production of variation. It governs both crossing-over and the movement of chromosomes in the reduction division. It was curiously this chance aspect of natural selection for which this theory was most often criticized. Some of Darwin's contemporaries, for instance the geologist Sedgwick, declared that invoking chance was unscientific. Actually, it is precisely the chanciness of variation that is so characteristic of Darwinian evolution. Even today there is much argument concerning the role of chance in the evolutionary process. Selection, of course, always has the last word.

Holistic thinking.

Reductionism was the declared philosophy of the physicalists. Reduce everything to the smallest parts, determine the properties of these parts, and you have explained the whole system. However, in a biological system there are so many interactions among the parts, for instance among genes of the genotype, that a complete knowledge of the properties of the smallest parts by necessity gives only a partial explanation. Nothing is as characteristic of biological processes as interactions at all levels, among genes of the genotype, between genes and tissues, between cells and other components of the organism, between the organism and its inanimate environment, and between different organisms. It is precisely this interaction of parts that gives nature as a whole, or the ecosystem, or the social group, or the organs of a single organisms, its most pronounced characteristics. To repeat what I said before, rejecting the philosophy of reductionism is not an attack on analysis. No complex system can be understood except through careful analysis. However the interactions of the components must be considered as much as the properties of the isolated components. And this is what the reductionists had neglected.

Conclusions.

We are now ready to summarize the results of our study of the autonomy of biology. Yes, we have concluded, that biology is a science, as much as chemistry and physics are sciences. However biology is in many respects a very different science from the so-called exact sciences. Perhaps the most pronounced difference is that biology, in part, is a historical science. In this part of biology, evolutionary biology, the method of historical narratives is the most heuristic approach. Furthermore, biology has as its subject matter living organisms which in several ways differ quite fundamentally from inanimate objects. They have, in particular, two characteristics for which there is no equivalent in the world of the physicist. One is that every process and every activity is controlled by a double set of causations; the natural laws and the genetic programs. The natural laws are the same that control the physical sciences. There is no room in biology for anything, as for instance vitalism, that would be in conflict with the natural laws. But every living organism and its parts is also controlled by a second source of causation, the genetic programs. The absence or presence of genetic programs denotes the sharp border between the inanimate and the living world. Typological (essentialistic) thinking is misleading when applied to organisms. What must be used instead is population thinking which realizes that in a biological population every individual is unique and differs from all others. The statistical mean value of a population is merely an abstraction. Dual causality as well as the uniqueness of every individual of a biopopulation characterize the world of living beings and are therefore characteristic for biology.

This explains why all endeavors prior to the last fifty years or so to construct a philosophy of biology within the conceptual framework of the physical sciences were such a failure. Biology, we now realize, is indeed largely an autonomous science and a philosophy of biology must be based on the peculiar characteristics of the living world, recognizing at the same time that this is not in conflict with a strictly physico-chemical explanation at the cellular-molecular level.

Literature

[l] E. Mayr: The idea of teleology. J. Hist. Ideas 53, 117 (1992). -
[2] E. Mayr: The multiple meanings of "Teleological". Hist. Phil. Life Sci. 20, 35 (1998).
[3] J. J. C. Smart: Philosophy and Scientific Realism. Routledge & Kegan Paul. London 1963.
[4] J. Beatty: The evolutionary contingency thesis. In G. Wolters, J. Lennox (Hrsg.): Concepts, Theories and Rationality in the Biological Sciences. University of Pittsburgh Press. Pittsburgh 1995.

adapted for the internet: Peter v. Sengbusch - b-online@botanik.uni-hamburg.de

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Κυριακή, 29 Ιουλίου 2012

Η ιδιοπροσωπία της Βιολογίας




Πρόσκληση  για Ανοικτό Διάλογο

Η ταυτότητα της Βιολογίας και η εξέλιξη των Βιοεπιστημών αποτελεί στην εποχή μας ένα πολυσυζητημένο θέμα που απασχολεί πλέον όχι μόνο τους Βιολόγους, αλλά το σύνολο σχεδόν των επιστημόνων και κοινωνικούς, πολιτικούς και οικονομικούς οργανισμούς.
Στο θέμα της ταυτότητας της Βιολογίας, η επιστημολογική της οντότητα και αυτονομία, αποτυπώνεται σε εκτεταμένη βιβλιογραφία όσο αφορά στα  ιδιοχαρακτηριστικά της (1,2,3)  και την ανταπόκρισή της στα επιστημολογικά κριτήρια του Moore (4).

Εν τούτοις λόγοι που πηγάζουν από:

α) την ιστορία  των επιστημών (και την μικρή συγκριτικά «ηλικία» της σύγχρονης Βιολογίας),
β) την διευρυνόμενη διασύνδεση της Βιολογίας με άλλα επιστημονικά πεδία (Φυσική, Χημεία, Μαθηματικά, Ηθική,…) και ιδιαίτερα τις ανθρωπιστικές επιστήμες,
γ) ετερόκλιτα συμφέροντα που αναπτύσσονται -ιδιαίτερα στην περίοδο κρίσης που βιώνουμε- λόγω της αλματώδους ανάπτυξης των ερευνητικών και γνωστικών πεδίων των Βιοεπιστημών και ειδικά των εφαρμογών τους στην διατροφή, στο περιβάλλον, στην υγεία, στην ενέργεια,
έχουν ως αποτέλεσμα να αναδύονται ερωτήματα που τείνουν να αμφισβητούν την οντότητα (5) και να …θολώνουν την επιστημολογική της «αυτάρκεια» ή ακόμη και την εννοιολογική της συνέχεια.

Στο πρόσφατο συνέδριο της ΠΕΒ «Η Βιολογία στην Εκπαίδευση» (Απρίλιος 2012) τέθηκαν ειδικότερα ερωτήματα όπως:
ü Πως συμβαίνει η Νέα Βιολογία να διασυνδέεται όλο και περισσότερο με γνωστικά πεδία της φυσικής, χημείας, μαθηματικών, πληροφορικής κ.α. και συνάμα να διατηρεί την αυτονομίας της;
ü Ενέχει ορθολογισμό η «κατάταξη» της Βιολογίας ως «βασική επιστήμη της ιατρικής», όταν η τελευταία οριοθετείται μόνο στα ζητήματα βιολογίας του ανθρώπου που αφορούν στην υγεία του και μάλιστα αρκείται (κατά βάση) στην εμπειρική αντιμετώπιση τους;
ü Είναι ορθολογικότερη η αντικατάσταση της κατάταξης  «επιστήμες της φύσης» (βλ Φυσικές επιστήμες) από την κατάταξη : «Επιστήμες ζωής και επιστήμες ανόργανης ύλης»;
ü Ακόμη και αν δεχθούμε την κριτική που ασκείται εκ μέρους των φιλοσόφων της Βιολογίας, ότι πολλοί Βιολόγοι δεν γνωρίζουν το πόσο απέχει η Βιολογία από τις φυσικές επιστήμες, ποια είναι η «χρησιμότητα» αυτής της παραδοχής; Μήπως έτσι τροχοδρομήσουμε …κλαδικές αλλαγές που δεν έχουν ωριμάσει;!

Με αυτές τις πλέον πρόσφατες …αφορμές, κρίναμε σκόπιμο να εγκαινιάσουμε καταρχήν αυτό τον  e-διάλογο, για το βασικό ζήτημα της Ιδιοπροσωπίας της Νέας Βιολογίας. Συνάμα πιστεύουμε ότι αυτή η συζήτηση θα ξεκαθαρίσει μια σημαντική παρανόηση, που σκοπίμως η όχι καλλιεργείται σήμερα και ειδικά στην χώρα μας: η όποια διασύνδεση με άλλες επιστήμες αποτελεί (μόνο ή απλά) μια επιμεριστική προσέγγιση ενός φαινομένου, που ωστόσο απέχει από το ενοποιητικό πνεύμα και την ολιστική προσέγγιση που απαιτεί κάθε βιολογικό φαινόμενο. (6)

Για την υποστήριξη της έναρξης του διαλόγου ζητήσαμε από τον καθηγητή κ. Στάμου -κύριο ομιλητή στο εν λόγω συνέδριο-  να καταγράψει τις απόψεις του για το θέμα. Η ανταπόκριση ήταν θετική και το σχετικό του κείμενο επισυνάπτεται. Παράλληλα παραθέτουμε δύο κείμενα του E. Mayr εστιασμένα στην ταυτότητα της Βιολογίας, ενώ συνιστούμε την ανάγνωση σχετικού κειμένου της ECBA Βιο2020 (www.ecba.com) , που αναφέρεται τόσο στα χαρακτηριστικά της  Νέας Βιολογίας, όσο και σε ζητήματα πολιτικής και εκπαίδευσης. Τέλος συνιστούμε το εμπεριστατωμένο ντοκουμέντο των Εθνικών Ακαδημιών των ΗΠΑ”A New Biology in the 21st Century” που αποτελεί σήμερα ίσως το ποιο ολοκληρωμένο πόνημα όσο αφορά στην «Νέα Βιολογία». (7)
Προσκαλούμε κάθε συνάδελφο που θέλει να τοποθετηθεί ή να διευκρινίσει κάποιο ζήτημα, να μας στείλει την άποψή του που μπορούμε –με την έγκρισή του- να την αναρτήσουμε στον ιστότοπο μας.

Βιβλιογραφία
(προφανώς ενδεικτική)

1.     Ε.MayrThe biological thoughtκεφ.2 εκδόσεις ΜΙΕΤ
2.     E Mayr, «Αυτή είναι η Βιολογία» σελ 38, εκδόσεις Κάτοπτρο.
3.     Steven Rose,  “Τα μονοπάτια της ζωής», εκδόσεις Κάτοπτρο.
4.     Moore  JA, “Science as a Way of Knowing” Cambridge, Harvard Univercity Press.
5.     Weinberg S, “Dreams of a Final Theory” (Όνειρα για μια τελική Θεωρία) Κάτοπτρο.
6.      Kafatos F, Eisner T, “Unification in the century of Biology” www.sciencemag.org SCIENCE VOL 303 27 FEBRUARY 2004
7.     A New Biology in the 21st Century : “Biological research is in the midst of a revolutionary change due to the integration of powerful technologies along with new concepts and methods derived from inclusion of physical sciences, mathematics, computational sciences, and engineering. As never before, advances in biological sciences hold tremendous…(απόσπασμα από τον πρόλογο-κείμενο 96 σελίδων) , 2011. http://www.nap.edu/catalog.php?record_id=12764  

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Σάββατο, 28 Ιουλίου 2012

Δαρβινική Βιολογία και Νευτώνια Φυσική: Αφηγήσεις έναντι νόμων Γ.Π. Στάμου Τμήμα Βιολογίας, Α.Π.Θ.




Αποφαίνονται ορισμένοι ότι συγκρινόμενη με τη νευτώνια φυσική η βιολογία δεν είναι ώριμη επιστήμη καθόσον στερείται νόμων, αυστηρής τυποποίησης και προβλεπτικής ισχύος. Υποστηρίζουν, αντίθετα, ότι αυτή βρίσκεται στα αρχικά στάδια της πορείας της προς την ωριμότητα. Οι αποφάνσεις αυτού του είδους εδράζονται στη θετικιστική αντίληψη περί επιστημονικής προόδου όπου μια επιστήμη θεωρείται ωριμότερη μιας άλλης ανάλογα με την έκταση κατά την οποία αυτή διαθέτει αυστηρούς τυπικούς νόμους και επομένως, πάντα κατά τους θετικιστές, ισχυρότερη εξηγητική και προβλεπτική δυνατότητα. Και πάλι κατά τους θετικιστές, η επιστήμη της φυσικής συνιστά πρότυπο ωριμότητας στο οποίο όλες οι άλλες πρέπει να μοιάσουν.

Το πρόβλημα με το θετικισμό, που σημειωτέον βρίσκεται σε παρακμή τα τελευταία χρόνια, έγκειται στο γεγονός ότι δεν αντιλαμβάνεται την ασυμβατότητα που υφίσταται ανάμεσα στις επιστήμες και άρα τη ματαιότητα των μεταξύ τους συγκρίσεων. Σε ό,τι ακολουθεί θα περιοριστώ σε συγκρίσεις της βιολογίας - στη δαρβινική της εκδοχή - με τη νευτώνια φυσική και θα προσπαθήσω να δείξω ότι ανάμεσα τους υφίστανται διαφορές και ασυμβατότητες που αναφέρονται τόσο στα δομικά τους στοιχεία, όσο και στις μεταφυσικές και ιδεολογικές τους παραδοχές, εντέλει στα κοσμοείδωλα που σκιαγραφεί η κάθε μια.   

Να αρχίσω με τα δομικά στοιχεία ανατρέχοντας στον Kuhn ο οποίος πριν αρκετά χρόνια, το 1970, χρησιμοποίησε τον όρο ‘επιστημονικό παράδειγμα’ για να περιγράψει ένα σύνολο από πεποιθήσεις, αξίες, νόμους, θεωρίες, αναπαραστάσεις, μεθόδους και τεχνικές, λεξιλόγιο κλπ που μοιράζονται οι επιστήμονες ενός κλάδου και οι οποίοι στο πλαίσιο μιας επιστημονικής περιοχής συγκροτούν διακριτή ομάδα -invisible college είναι ο όρος που χρησιμοποιεί-. Αργότερα, το 1977 οι Darden και Maull καθώς και ο Bechtel το 1986 χρησιμοποίησαν τον όρο ‘επιστημονικό πεδίο’ τη δομή του οποίου κωδικοποιήσαμε με τον Κορφιάτη τo 1994 ως εξής: το κάθε επιστημονικό πεδίο περιλαμβάνει α) ερευνητικό αντικείμενο (για τη βιολογία ο έμβιος κόσμος), β) θεωρητικό πυρήνα (εδώ η νεοδαρβινική κατασκευή), γ) περιφερειακές θεωρητικές κατασκευές, π.χ. η θεωρία αριστοποίησης της τροφοληψίας, δ) δική του μέθοδο διατύπωσης ερωτημάτων και απάντησης σε αυτά, ε) λεξιλόγιο και ερευνητικά εργαλεία που του προσιδιάζουν.

Με βάση τα παραπάνω θα προχωρήσω στην πρώτη μου διαπίστωση, ότι δηλαδή ανάμεσα στη νευτώνια φυσική και τη βιολογία υφίστανται θεμελιακές δομικές αποκλίσεις. Μια απ’ αυτές έχει να κάνει με το ερευνητικό αντικείμενο όπου η φυσική ασχολείται με το ανόργανο σύμπαν και η βιολογία με τον κόσμο της ζωής. Εδώ θα μπορούσε κανείς να παρατηρήσει ότι παρά τις διαφορές στο ερευνητικό αντικείμενο οι δύο επιστήμες μοιράζονται άλλα στοιχεία όπως για παράδειγμα την αναγωγική μεθοδολογία. Η απάντηση σχετικά με τη συγκεκριμένη μεθοδολογία είναι ότι στο χώρο της βιολογίας, τουλάχιστον στο χώρο της οικολογίας, η διαμάχη περί τον αναγωγισμό και τον ολισμό υπήρξε πάντοτε ψευδοπρόβλημα. Δε θα επιμείνω εδώ, θα πω μονάχα ότι, όπως έχει δειχτεί σε άλλες ευκαιρίες, στην επιστημονική πράξη επικρατούσε πάντοτε ο συμβιβασμός ανάμεσα σε ολιστικά κοσμοείδωλα και αναγωγικές μεθοδολογίες.

Ξεπερνώ στα γρήγορα την ψευδοδιαμάχη ανάμεσα στον αναγωγισμό και τον ολισμό για να εστιάσω στο σύνολο των δομικών στοιχείων που χτίζουν τα επιστημονικά πεδία και να υποστηρίξω ότι είναι αδύνατον δύο πεδία με διαφορετικά στοιχεία, π.χ. διαφορετικά αντικείμενα, να διαθέτουν κοινή μεθοδολογία και το αντίστροφο. Το στηρίζω αυτό στο ότι τα στοιχεία που συγκροτούν ένα επιστημονικό πεδίο, δηλαδή το αντικείμενο, ο θεωρητικός πυρήνας, οι περιφερειακές κατασκευές, τα εργαλεία, το λεξιλόγιο κλπ έχουν πίσω τους ιστορικό συνεξέλιξης. Συνεξελισσόμενα λοιπόν αυτά τα στοιχεία δένονται το ένα με το άλλο και συγκροτούν αδιάσπαστη διαλεκτική ενότητα. Τούτο σημαίνει ότι οι έννοιες και τα εργαλεία, οι μέθοδοι και το γλωσσάρι αλληλοεξαρτώνται και αποκτούν το δικό τους ιδιαίτερο περιεχόμενο στα διαφορετικά επιστημονικά πεδία. Για παράδειγμα, ο όρος ανταγωνισμός είναι κοινός στη βιολογία και την οικονομία, όμως πέρα από επιφανειακές αναλογίες το νόημα των δύο όρων είναι απολύτως διαφορετικό στα δύο διαφορετικά πεδία. Η έννοια ανταγωνισμός δεν έχει συγκεκριμένο βιολογικό περιεχόμενο πριν ανταμωθεί στο πλαίσιο του πεδίου της βιολογίας με συγκεκριμένο αντικείμενο - τη μελέτη των φαινομένων της ζωής -, το δαρβινικό κοσμοείδωλο, την ειδική μεθοδολογία για τη μελέτη των εξελικτικών φαινομένων, τα πειραματικά εργαλεία και το συγκεκριμένο λεξιλόγιο. 

Υποστηρίζω επιπρόσθετα ότι το κάθε επιστημονικό πεδίο βρίσκεται σε μια διαρκή κίνηση και αλλαγή και ότι μια οποιαδήποτε μεταβολή σε ένα στοιχείο της διαλεκτικής ενότητας π.χ ένας τεχνολογικός νεωτερισμός θα συμπαρασύρει υποχρεωτικά αλλαγές μεγαλύτερου ή μικρότερου εύρους και στα υπόλοιπα στοιχεία, δηλαδή στο θεωρητικό πυρήνα, τα εργαλεία, το λεξιλόγιο κλπ. Καταλήγω λοιπόν ότι στη βάση της διαλεκτικής των πραγμάτων είναι λογικά αδύνατον δύο διαφορετικά επιστημονικά πεδία να έχουν διαφορετικά αντικείμενα αλλά όμοια μεθοδολογία και το αντίστροφο και το ίδιο συμβαίνει με όλα τα δομικά στοιχεία. Και ακόμη ότι αυτές οι διαφορές συνεπάγονται δομικές ασυμβατότητες ανάμεσα στις επιστήμες, εδώ της νευτώνιας φυσικής από τη μια και της δαρβινικής βιολογίας από την άλλη.

Η προβληματική μου τώρα θα στραφεί στο γεγονός ότι, πέρα από τις επιστημονικές πεποιθήσεις, το κάθε επιστημονικό πεδίο χαρακτηρίζεται από πληθώρα φιλοσοφικών, μεταφυσικών και μεθοδολογικών, παραδοχών. Για παράδειγμα, η έρευνα στο χώρο της δυναμικής πληθυσμών προϋποθέτει ομοιογένεια χώρου έτσι ώστε να μην τίθενται φραγμοί στη συνεύρεση των αρσενικών με τα θηλυκά άτομα, στη διαθεσιμότητα τροφικών και λοιπών διαθεσίμων κλπ. Προϋποθέτει ακόμα ομοιογένεια  χρόνου ώστε οι ρυθμοί αναπαραγωγής, αύξησης και θανάτου να παραμένουν σταθεροί στη διάρκεια του χρόνου. Προϋποθέτει, τέλος, και ομοιογένεια του βιολογικού υλικού καθόσον τα άτομα της κάθε ηλικιακής κλάσης θεωρούνται μεταξύ τους όμοια και έτσι γίνεται δυνατός ο υπολογοσμός κατά κεφαλήν ρυθμών γεννητικότητας, οντογένεσης και θνησιμότητας. Μάλιστα, στην πρώτη τους έκδοση τα σχετικά μοντέλα προϋπέθεταν και αποκλειστικά εσωτερική αιτιότητα καθόσον το σύστημα είναι κλειστό οπότε και οι πληθυσμιακές μεταβολές εξηγούνται μονοσήμαντα από το επίπεδο στο οποίο βρίσκεται ο ενδοειδικός ανταγωνισμός.

Κατά κανόνα οι παραδοχές αυτές δεν εκφράζονται ρητά είναι όμως αυτές που μέρα με τη μέρα, ώρα με την ώρα επηρεάζουν τον τρόπο με τον οποίο τίθενται οι ερωτήσεις, στοιχειοθετούνται τα προβλήματα, διατυπώνονται οι υποθέσεις εργασίας, καταστρώνονται τα πειραματικά σχέδια, ενώ υπερκαθορίζουν και τις ερμηνείες. Για παράδειγμα, ανεξάρτητα με το κατά πόσον αυτό θα εκφραστεί ρητά ή όχι, αν παραδεχθούμε ότι η ισορροπία αποτελεί θεμελιακό χαρακτηριστικό (κατηγόρημα) του κόσμου εκεί έξω τότε μεταξύ άλλων η δυναμική πληθυσμών θα ενδιαφερθεί για το επίπεδο πληθυσμιακής εξισορρόπησης, το χρόνο που θα απαιτηθεί ώστε ο πληθυσμός να φτάσει στην ισορροπία και άλλα παρόμοια. Με βάση την παραπάνω ερωτηματοθεσία το πείραμα θα επιδιώξει, ανάμεσα στα άλλα, να περιγράψει τις συνέπειες της πυκνοεξάρτησης επί των δημογραφικών παραμέτρων, ενώ και οι ερμηνείες θα κινηθούν σε ανάλογο μήκος κύματος. Αν, αντίθετα, η προκείμενη ρητή ή υπόρρητη παραδοχή είναι ότι το πληθυσμιακό μέγεθος μεταβάλλεται συνεχώς υπό την πίεση περιβαλλοντικών διαταραχών τότε μερικές από τις ερωτήσεις θα αφορούν στη στοχαστικότητα που χαρακτηρίζει το μέγεθος, τη διάρκεια και τη συχνότητα των φυσικών διαταραχών, τις συνέπειές τους πάνω στη πληθυσμιακή δημογραφία και ανάλογοι θα είναι οι πειραματικοί σχεδιασμοί καθώς και οι ερμηνείες.

Στη συνηθισμένη περίπτωση όπου οι προκείμενες παραδοχές είτε δεν αναγνωρίζονται είτε δεν λαμβάνονται σοβαρά υπόψη οδηγούν την ερευνητική πρακτική σε αδιέξοδα. Αυτό συνέβει για παράδειγμα με το οικοσύστημα, και ειδικά με την ιδέα ότι τα όρια του ορίζονται την κάθε φορά ανάλογα με τις ανάγκες της έρευνας. Συγκεκριμένα, εδώ αγνοήθηκε ότι, ασχέτως του αν δηλώνονται ρητά ή όχι, στο θετικιστικό πλαίσιο διαπραγμάτευσης του βιολογικού ζητήματος ο βιολογικός ρεαλισμός έχει συγκεκριμένα χαρακτηριστικά που παράγονται εντός μιας ορισμένης μεταφυσικής. Πράγματι, τον καιρό που διατυπωνόταν η έννοια του οικοσυστήματος στο χώρο της βιολογία κυριαρχούσαν ρεαλιστικές αντιλήψεις που όριζαν ότι οι βιολογικές οντότητες υφίστανται αντικειμενικά εκεί έξω και είναι αποτέλεσμα εξέλιξης. Ένα δεύτερο χαρακτηριστικό αυτής της μεταφυσικής είναι ότι η εξέλιξη γίνεται αντιληπτή πάντα σε σχέση με το αβιοτικό και το βιοτικό περιβάλλον (asssoccionalism), αλλιώς τα φαινόμενα δεν έχουν νόημα. Λοιπόν, σχέσεις ανάμεσα σε βιολογικές και φυσικοχημικές οντότητες που υφίστανται πραγματικά εκεί έξω και νοούνται σε μια εξελικτική προοπτική και μάλιστα σε σχέση με ένα συγκεκριμένο περιβάλλον. 

Με άλλα λόγια ιστορικές διαδικασίες που διαδραματίζονται εντός συγκεκριμένου και αντικειμενικά οριζόμενου χωροχρόνου. Αυτό σημαίνει ότι όταν, για παράδειγμα, μιλάμε στο επίπεδο της γενετικής και της οικολογίας η βιολογική οντότητα ‘πληθυσμός’ οφείλει να οριοθετείται με σαφήνεια στον οικολογικό χώρο και τον οικολογικό χρόνο. Το ίδιο ισχύει και για την οντότητα ‘είδος’ που ορίζεται στο ευρύτερο επίπεδο του χώρου της γεωγραφίας και του χρόνο της μακροεξέλιξης, ή σύμφωνα με το σύγχρονο νεολογισμό στο χώρο και το χρόνο της μακροοικολογίας. Ε λοιπόν, η θετικιστική αναγκαιότητα που απαιτεί ιστορικά συγκεκριμένες οντότητες αγνοήθηκε στην περίπτωση του οικοσυστήματος. Το αποτέλεσμα ήταν η ασυνέπεια ανάμεσα στις μεταφυσικές παραδοχές και την καθημερινή πράξη και για το λόγο αυτό το πλαίσιο διαπραγμάτευσης των ζητημάτων έχασε τη συνοχή του. Στην πράξη, η αδυναμία οριοθέτησης του οικοσυστήματος επέσυρε οξύτατη κριτική και δημιούργησε άλυτες αντινομίες στο χώρο της συστημικής οικολογίας. Μάλιστα, λειτούργησαν τόσο στρεβλωτικά αυτές οι αντινομίες ώστε στη σημερινή ερευνητική πράξη η χρήση του όρου να έχει εγκαταλειφθεί σχεδόν ολοκληρωτικά.

Πέρα από την ανάδειξη της σημασίας που έχουν οι μεταφυσικές και ιδεολογικές προκείμενες για την επιστημονική πράξη, από όλα τα παραπάνω φτάνουμε και σε ένα δεύτερο συμπέρασμα, όπου προϋπόθεση της δαρβινικής βιολογίας είναι η ιστορικότητα των φαινομένων και κατά συνέπεια η ανάγκη για σαφήνεια στο χώρο και το χρόνο. Θα ισχυριστώ στη συνέχεια ότι το γεγονός αυτό καθιστά το ‘ρεαλισμό’ και το ‘συγκεκριμένο’ γνωρίσματα της βιολογικής σκέψης και μάλιστα γνωρίσματα που υπερ-προσδιορίζουν το δαρβινικό κοσμοείδωλο και το διαφοροποιούν από το νευτώνιο. Πράγματι, στο αν-ιστορικό πεδίο της φυσικής όπου κυριαρχούν η απουσία χώρου και η συγχρονία έναντι του βιολογικού χώρου και της διαχρονίας είναι θεμιτό η επιστημονική πρακτική να εμπλέκει φανταστικές οντότητες όπως είναι το ηλεκτρόνιο, το φωτόνιο, ή το νετρίνιο. Οι οντότητες αυτές αποτελούν ιδεατά τεχνουργήματα (artifacts) που δεν έχουν σχέση με τον πραγματικό κόσμο εκεί έξω και χρησιμοποιούνται ως εργαλεία επιστημονικής έρευνας. Χάρη σε αυτές τις οντότητες/εργαλεία οι επιστήμονες κατορθώνουν να διαχειριστούν την επιστημονική παρατήρηση και να μιλήσουν για την ενιαία υλική ουσία των πραγμάτων που υποτίθεται στέκει αναλλοίωτη πίσω από τα φαινόμενα. Εδώ έχουμε να κάνουμε με εργαλειακού τύπου οντολογία και ουσιοκρατία (essentialism).

Από όσο μπορώ να ξέρω όποτε επιχειρήθηκε να εγκαθιδρυθεί στο χώρο της βιολογίας εργαλειακή οντολογία αυτό οδήγησε σε σοβαρές επιστημονικές κρίσεις. Αντίθετα, η αγωνιώδης αναζήτηση από τους επιστήμονες του κλάδου συγκεκριμένης κάθε φορά υλικής βάσης για το γονίδιο, το είδος, τη βιοκοινότητα, το οικοσύστημα κλπ, που χαρακτηρίζουν τη βιολογική έρευνα, βρίσκεται στον αντίποδα της εργαλειακότητας.

Ισχυρίζομαι λοιπόν ότι σε αντίθεση με τη νευτώνια ουσιοκρατία, η δαρβινική βιολογία εδράζεται σε ρεαλιστική οντολογική βάση που προβάλλει όχι ουσιοκρατικά αλλά, όπως θα επιχειρήσω να δείξω στη συνέχεια, σχεσιακά (relationist) χαρακτηριστικά και εδώ θα αφιερώσω το υπόλοιπο αυτού του κειμένου. Σχετικά με το ρεαλισμό σημειώνω ότι για τη βιολογία οι οντότητες όπως το γονίδιο, ο οργανισμός, ο πληθυσμός, η βιοκοινότητα υφίστανται πραγματικά εκεί έξω ανεξάρτητα από τις αντιλήψεις που έχει ο βιολόγος, αλλά και τις έννοιες, τα μοντέλα και τα πειραματικά εργαλεία που χρησιμοποιεί. Με άλλα λόγια η ουσία και οι ιδιότητες αυτών των οντοτήτων είναι ανεξάρτητες από τις πρακτικές που χρησιμοποιεί ο επιστήμονας προκειμένου να τις γνωρίσει. Στην παρατήρηση, ότι και τα μοντέλα είναι υποκειμενικές διανοητικές κατασκευές, η απάντηση είναι ότι αυτά δεν υπέχουν θέση οντότητας αλλά απλού εργαλείου. Όπως δηλώνεται ρητά, οι οντότητες υφίστανται εκεί έξω αντικειμενικά και τα μοντέλα δεν είναι παρά διανοητικές κατασκευές που έλκουν μεν την έμπνευσή τους από την πραγματικότητα, αλλά με κανέναν τρόπο δεν είναι η πραγματικότητα, έστω και απλοποιημένη. Χρησιμοποιούνται απλά ως εργαλεία κατά τη διαδικασία παραγωγής γνώσης σχετικά με την πραγματικότητα.

Οι οντολογικές και οι μεθοδολογικές διαφορές που σημείωσα πιο πάνω έχουν συνέπειες και για τις ερωτήσεις που μπορούν να διατυπωθούν στα πλαίσια των δύο διαφορετικών επιστημονικών πεδίων. Έτσι, η εργαλειακότητα της νευτώνιας φυσικής, ακόμα και στις πιο ήπιες εκδοχές της, θέλει τις θεωρητικές κατασκευές που φιλοτεχνούν οι επιστήμονες για τον κόσμο εκεί έξω (αφηρημένες έννοιες, όπως η δύναμη, η θερμότητα, η βαρύτητα κ.ά, αλλά και θεωρητικές οντότητες, όπως το ηλεκτρόνιο) να αξιολογούνται ανάλογα με τη χρησιμότητά τους και όχι με όρους αλήθειας ή πλάνης. Έτσι, στο πλαίσιο του εργαλειακού λόγου οι θεωρητικές κατασκευές όπως π.χ. το τρισδιάστατο μοντέλο για το γονίδιο, οι τροχιές των ηλεκτρονίων, το νετρίνιο κ.ά δεν είναι τίποτα άλλο από αυθαίρετες επινοήσεις του νου που επιτρέπουν στον επιστήμονα να ερμηνεύσει τα δεδομένα της παρατήρησης, να συγκρίνει και να ομαδοποιήσει παρατηρήσεις και να φτάσει σε προβλέψεις. Σε αυτό το πλαίσιο το οικοσύστημα π.χ. θα πρέπει να θεωρηθεί ως απλό λογισμικό που επιτρέπει να υπολογιστεί, ανάμεσα στα άλλα, ο ρυθμός ανακύκλωσης της βιομάζας. Για τον ίδιο λόγο, ως θεωρητική κατασκευή, η βιοκοινότητα θα έπρεπε να θεωρηθεί απλή μαθηματική μήτρα που επιτρέπει την ενοποίηση των αποτελεσμάτων που δίνουν τα σχετικά μοντέλα δυναμικής πληθυσμών. Νομίζω ότι δε χρειάζεται να επιμείνω εδώ για να δείξω ότι δεν είναι αυτός ο τρόπος που σκεπτόμαστε στο πλαίσιο του βιολογικού ρεαλισμού. 

Φαντάζομαι ότι έγινε φανερό από τα παραπάνω ότι ο επιστημονικός ρεαλισμός για τον οποίο κάνω εδώ λόγο πηγάζει από την ιστορικότητα που ενέχει ο λόγος της βιολογίας και επομένως από τη σημασία που έχει ο χώρος και ο χρόνος για την ανέλιξη των φαινομένων της ζωής. Εδώ θα μπορούσε να σημειώσει κανείς ότι σε αντίθεση με την καθολικότητα  που χαρακτηρίζει τα σχετικά ώριμα επιστημονικά πεδία, όπως εκείνο της νευτώνιας φυσικής (οι φυσικοί νόμοι έχουν καθολική ισχύ ανεξαρτήτως χώρου και χρόνου) η ανάγκη ακριβούς προσδιορισμού χωροχρονικών ορίων αποτελεί γνώρισμα ανωριμότητας της δικής μας επιστήμης. Θα αντιτείνω από την πλευρά μου ότι στην πραγματικότητα αυτό που αντιπαρατίθεται εδώ είναι από τη μια μεριά η καθολικότητα και η αφαιρετικότητα της νευτώνιας φυσικής, με θεμελιακό αίτημα το ‘είναι’ (από τί είναι φτιαγμένος ο κόσμος εκεί έξω) και από την άλλη η ανάγκη εστίασης στο συγκεκριμένο που απαιτεί η βιολογία με θεμελιακό αίτημα το ‘υπάρχειν’ δηλαδή το πώς λειτουργεί ο έμβιος κόσμος που υπάρχει εκεί έξω. Αυτό όμως καθόλου δεν έχει να κάνει με ωριμότητες και ανωριμότητες. Έχει αντίθετα να κάνει με τα διαφορετικά σύμπαντα που μελετούν η φυσική και η βιολογία. Συγκεκριμένα, το σύμπαν που μελετά ο φυσικός υποτίθεται ότι έχει παντού ενιαία δομή και λειτουργία. Οι ίδιοι νόμοι ισχύουν παντού και πάντα, στη γη και το φεγγάρι, χτες, αύριο αλλά και πριν πενήντα ή μετά εκατό έτη. Για το λόγο αυτό η φυσική νομολογία διαπερνά ολόκληρο το νευτώνιο σύμπαν. Αντίθετα, το δαρβινικό σύμπαν θεωρείται ιεραρχημένο και λειτουργεί πάντα σε αναφορά με ένα συγκεκριμένο περιβάλλον. Έτσι, γίνεται αποδεκτό ότι το κύτταρο έχει διαφορετικές ιδιότητες από τον οργανισμό, αυτός από τον πληθυσμό και ο τελευταίος από τη βιοκοινότητα. Κοντολογίς, η βιολογία αποδέχεται την έννοια της ανάδυσης όπου σε κάθε επίπεδο αναδύονται δομές, σχέσεις και ιδιότητες που στερούνται νοήματος σε κατώτερα επίπεδα. Δέχεται ακόμα ότι αυτά τα νοήματα εμφανίζονται υπό διαφορετικές εκδοχές από τον ένα τόπο στον άλλον καθώς και από τη μια χρονική στιγμή στην άλλη. Επομένως, αντί επί του καθολικού, η βιολογία επικεντρώνεται επί του συγκεκριμένου και ιδίως επί των συγκεκριμένων σχέσεων των οργανισμών με τα βιοτικά και τα αβιοτικά στοιχεία του περιβάλλοντος.

Μετά από όλα τα παραπάνω είμαι έτοιμος τώρα να προχωρήσω κι ένα βήμα περισσότερο και να αντιπαραθέσω στην ουσιοκρατία της φυσικής με τη σχεσιοκρατία της βιολογίας. Ας δούμε την εύλογη ερώτηση για το πού τελειώνουν τα όρια μιας τροφικής αλυσίδας στο πεδίο. Ε λοιπόν, η απάντηση δεν μπορεί παρά να δοθεί με όρους βιολογικών λειτουργιών δηλαδή με κριτήρια σχεσιακά. Τότε τα χωρικά όρια της τροφικής αλυσίδας εξισώνονται με το χώρο όπου αυτές οι διαδικασίες ολοκληρώνονται. Αν ορισθούν με αυτόν τον τρόπο, τα όρια αλλάζουν από τη μια περιοχή στην άλλη, αλλά και από τη μια χρονική στιγμή στην άλλη. Και να προσθέσω και κάτι ακόμα πιο ριζοσπαστικό: μιλώντας για απροσδιοριστία και σχετικότητα ορίων στο χώρο της βιολογίας αναφερόμαστε μάλλον στους αστάθμητους παράγοντες οι οποίοι έχουν μεγάλη βαρύτητα για τα φαινόμενα της ζωής και μάλιστα τόσο πολύ ώστε η αυξημένη στοχαστικότητα να αποτελεί κυρίαρχο γνώρισμα του βιολογικού χώρου και του βιολογικού χρόνου. Κοντολογίς, τα φαινόμενα αποκτούν ακέραιο το βιολογικό τους νόημα στις σχέσεις που αναπτύσσονται στο πλαίσιο της καθημερινής βιολογικής πράξης πράγμα που με κάνει να αποτολμήσω τον αφορισμό ότι πρώτα απ’ όλα και πάνω απ’ όλα η βιολογία είναι επιστήμη της πράξης και του συγκεκριμένου, σε αντίθεση με τη νευτώνια φυσική που είναι η επιστήμη του ιδεατού και του αφηρημένου. Δεν υφίστανται a priori καθολικά βιολογικά νοήματα, αυτά διαμορφώνονται κάθε φορά ανάλογα με τις σχέσεις που οικοδομούνται στο πλαίσιο των εκάστοτε οικολογικών σχηματισμών. Το DNA της βιολογίας δεν είναι ένα χημικό μόριο γενικώς. Σε αντίθεση με το χημικό, το βιολογικό DNA δε γίνεται αντιληπτό ως καθολική ουσία. Αυτό αποκτά το βιολογικό του νόημα με βάση το ρόλο που διαδραματίζει στην καθημερινή πράξη της ζωής και μάλιστα όχι στο εργαστήριο όπως συχνά θεωρούμε αφελώς, αλλά στον πραγματικό βιολογικό κόσμο εκεί έξω.

Με όλα τα παραπάνω θέλησα να στοιχειοθετήσω το δεύτερο ερώτημά μου το οποίο αναφέρεται στα διαφορετικά κοσμοείδωλα, δηλαδή τις διαφορετικές ιδέες και τις διαφορετικές μεταφυσικές παραδοχές μέσω των οποίων προσλαμβάνονται το φυσικό και το βιολογικό σύμπαν. Θα πάω και λίγο παραπέρα για να υποστηρίξω ότι σήμερα που ανθίζουν γύρω μας οι ιδέες του εποικοδομητισμού (constructionism) μπορούμε να περιγράψουμε την εικόνα που πάντα ίσχυε στο χώρο μας, αλλά λόγω της κυριαρχίας του θετικισμού έφτανε ως εμάς παραμορφωμένη. Πρόκειται για το γεγονός ότι, σε αντίθεση με τη νευτώνια φυσική, το κοσμοείδωλο της βιολογίας ιχνογραφήθηκε στη βάση σχεσιακών αντιλήψεων με το εστιακό σημείο να μην ανήκει στις οντότητες καθεαυτές αλλά στις σχέσεις που αναπτύσσουν οι οντότητες με τα στοιχεία του βιοτικού και του αβιοτικού περιβάλλοντος και μάλιστα υπό καθεστώς αυξημένης στοχαστικότητας. Έτσι οι οντότητες ορίζονται ως σχέσεις μάλλον παρά ως ουσία. Σήμερα μιλάμε πια για σχεσιακές και όχι ουσιοκρατικές λογικές που δέχονται ότι ο φυσικός χωροχρόνος δεν έχει καν βιολογικό νόημα αφού τα όρια του φτάνουν μέχρι εκεί που εξαντλούνται οι σχέσεις και παύουν να λειτουργούν οι μηχανισμοί. Θα το διατυπώσω ως κατακλείδα δεν θα επεκταθώ όμως: είμαι της γνώμης ότι ο κριτικός ρεαλισμός με την έμφαση να πέφτει στις σχέσεις και στους μηχανισμούς που υπόκεινται των φαινομένων αποτελεί μια καλή βάση ώστε να περιγραφεί το κοσμοείδωλο της σύγχρονης βιολογίας. 

Το τελικό μου συμπέρασμα είναι ότι η καθολικότητα και η ουσιοκρατία πραγματώνονται στο πεδίο της φυσικής μέσω νόμων. Αντίθετα, η ιστορικότητα και η σχεσιοκρατία πραγματώνονται στο πεδίο της βιολογίας μέσω ιστορικών αφηγήσεων. Νόμοι έναντι αφηγήσεων λοιπόν και εδώ ανακύπτει το ακροτελεύτιο ερώτημα αυτού του κειμένου: διαθέτει η βιολογία προβλεπτική ισχύ συγκρίσιμη με εκείνη της φυσικής που αποτελεί έναν ακόμα λόγο αναγόρευσής της σε επιστήμη πρότυπο; Και εδώ η απάντηση είναι ότι η νομολογία από τη μια μεριά και η αφηγηματικότητα από την άλλη επιβάλλουν διαφορετικούς τύπους προβλέψεων. Πράγματι, οι προβλέψεις που επιχειρεί η βιολογία είναι διαφορετικές και άρα μη συγκρίσιμες με εκείνες της φυσικής. Στην πράξη, με βάση το ιστορικό του βιολογικού συστήματος, τον εκτιμούμενο βαθμό στοχαστικότητας των φαινομένων καθώς και το ποιές παράμετροι υπολογίζεται ότι θα επηρεαστούν, η αφήγηση του βιολόγου θα περιγράψει ένα σύνολο από εναλλακτικά μεν πλην πεπερασμένα μονοπάτια που θα ακολουθήσει το σύστημα στο μέλλον. Το τελικό προϊόν της πρόβλεψης θα είναι ένας τόπος σημείων όπου θα απεικονίζονται οι πιθανές μια-δυο-τρεις καταστάσεις στις οποίες την κάθε στιγμή μπορεί να βρεθεί το σύστημα. Προδήλως, η μέθοδος της βιολογίας είναι ιστορικοερμηνευτική και αποσκοπεί στην εκ των υστέρων ερμηνεία και όχι στην εκ των προτέρων πρόβλεψη. Αυτός είναι ένας ακόμα λόγος μεθοδολογικής αυτή τη φορά ασυμβατότητας ανάμεσα στη δαρβινική βιολογία και τη νευτώνια φυσική. 


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