Baerian biology:
evolution by means of organisms' interpretation

Kalevi Kull


Published in:

Kull K. 1998. Baerian biology: evolution by means of organisms' interpretation. - In: Farré George L., Oksala Tarkko (eds.). Emergence, Complexity, Hierarchy, Organization. Espoo, 197-200.


Abstract

In the place of the traditional opposition Darwin-Lamarck, a seemingly more interesting and profound one, Darwin-Baer, is briefly analyzed. This includes a reinterpretation of the Baldwin effect, which is based on directional interpretation shifts and stochastic forgetting of the unused. As a consequence, differences in fitness are not obligatory for evolution, the activity of subject becomes a factor of evolution, whereas Crick's central dogma is not violated. If the Baerian approach is usually considered to address macroevolution, then this shows that it may also have a great importance for understanding microevolution.

Keywords: Interpretation change, Baldwin effect, Baer, microevolution, inheritance systems, semiotic biology.



Darwin versus Baer

In the rich history of biology, two great lines of thinking can be distinguished - the Baerian, and the Darwinian. Defining only two categories in the classification is, of course, a great simplification. However, Romanticist and Victorian cultural trends, continental and Anglo-American schools in scientific discourse, structuralism and functionalism, or holism and reductionism in the backgrounds of the explanations, symbiosis versus competition serving as the primary interaction in living systems - these can be seen as parallels (which, apparently not so seldom, correspondingly coincide) with the same distinction.

J. v. Uexküll, a forerunner of semiotic biology, expressed the same opposition, when he noted the preference toward Merkseite versus Wirkseite, for instance by Kepler or Newton. "Kepler suchte nach dem Plan - Newton nach der Ursache der gleichen Erscheinung. /../ Seit Darwin waren die Biologen eifrig bemüht, die Merkseite der Lebewesen zu unterschlagen und nur ihre Wirkseite zu beachten" (Uexküll, 1937, 188-189).

According to the historian of biology M. Remmel (1992, 43), "Baer's principles are a remarkable generalization of the theory of ontogeny. Unfortunately, some traditional evolutionary paradigms including early pure selectionist views of strict darwinism have served as a kind of informational filter restricting the application of the conceptual apparatus of Baer's principles in biology and paleontology. /../ Baer's principles stand on the crossroads of three disciplines: taxonomy, embryology and evolutionary biology, making possible certain interdisciplinary logical projections".

One of the basic differences between the two approaches concerns the stress on development versus evolution. "Development, not evolution, could be considered as the central theoretical framework for biology. In this case Baer and not Darwin would become the central historical figure in theoretical biology" (Salthe 1993, 247). According to the Darwinian view, adaptation to the environment as a result of a struggle for existence and differential reproduction of genotypes is the main issue and mechanism in evolution, whereas the organic form itself provides the main evolutionary trends and innovations according to the other approach. The latter has its roots in the views of Leibniz, and later K. E. von Baer (1864), G. Teichmüller, D'Arcy Thompson, R. Woltereck, and others. This view is close to the structuralist approaches in biology of this century (Goodwin, Sibatani and Webster, 1989, Brauckmann and Kull 1997). Lamarckian biology, however, seems to be situated somehow in between - its teleology puts it closer to the Baerian line of thought, whereas its emphasis on the adaptation to the environment is more similar to that of Darwinism.

The opposition between Darwinian and Baerian approaches has often been seen as concerning only the details of interpretation in relationships between ontogeny and phylogeny. However, as S. J. Gould (1977, 73) writes, "If the goal of evolutionary theory is only to set up a series of pragmatic guidelines for the construction of evolutionary trees, then it makes no difference. But this would be an impoverished notion of evolutionary theory indeed. The two views imply radically different concepts of variation, heredity, and adaptation - the fundamental components of any evolutionary mechanism".

In this paper, I give a short description of the approach to microevolution as seen from the standpoint of Baerian (and semiotic) biology.


Heredity

E. Jablonka et al. (1998) distinguish between four inheritance systems: epigenetic (EIS), genetic (GIS), behavioral (BIS), and linguistic (LIS). The means of information transmission include, correspondingly, regeneration of cell structures and metabolic circuits (EIS), DNA replication (GIS), and social learning (BIS, LIS).These inheritance systems transmit variations from generation to generation, whereby the variations include cellular morphology (EIS), DNA base sequences (GIS), patterns of behavior (BIS), and language structures (LIS).

In addition to this, it is important to admit the role of the environment. For instance, the pattern of behavior of organisms can vary depending on the environment in which these organisms live, which means that particular behavioral forms are connected (or limited) to a particular environment. Thus, for instance, what can be inherited via BIS may be only the behavior used in concrete conditions, in cases where this environment holds. Therefore, the stability of environmental conditions is a necessary part of inheritance systems, being itself a carrier of a part of the information from generation to generation.

As opposed to the genocentric view of biological evolution, the distinction between several independent inheritance systems makes it clear that GIS cannot explain all that is going on in evolution. Also, we should consider that the change or stability of the environment (i.e., the environmental information) is itself an obligatory component of inheritance. Changes in any of these inheritance systems may have evolutionary consequences.


On the mechanism of adaptation: reinterpreting the Baldwin effect

According to what we know for certain today, genetic memory in cells is read-only. It can be copied, but it is not possible for a cell to store any new messages in it. From this, it is conventionally concluded that only genetic changes, and not phenotypic modifications, have an importance for evolution.

However, what the semiotic approach to organisms teaches us, is that the genome does not determine phenotype, but that the organism, in each stage of its development, interprets its genome when producing phenotype, and this interpretation can be shifted depending on the context of Umwelt. The genotype- phenotype interaction is not that of determination - it is interpretation.

In other words, the DNA sequence does not specify many features of organisms. For instance, organisms with identical DNA may vary in gene expression, in their morphology and physiology, in behavior and language. Also, these differences can be inherited over several generations, even in if no changes in genotype occur. Emergence of new features in organisms can, therefore, appear due to the changes in any inheritance system or in the environment.

Accepting this, it is still not clear what is the relative importance of different inheritance systems for biological evolution.

Thus, the problem remains, what can an organism as a subject do to influence its evolution, considering that it cannot write anything into its genetic memory (cf. Weingarten 1993).

An answer to this question can be formulated as follows: an organism can influence its evolution via changes in the usage of different parts or pieces of its genome, or shifts of their meaning (or function), which result in a certain ambiguity in the meaning of mutation, and via a possibility to fix this change in its genetic memory (due to stochastic genetic modifications which may make the changes irreversible), i.e. by forgetting the unused or unnecessary. This is possible, if the organism has a degree of freedom; and this it has, due to its communication with the outer world or other organisms, due to its engagement in triadic processes, or in functional circles.

Or, in short: an organism can change the interpretation of its genetic memory, even despite the constancy of the latter. The genome can thus be compared to an ordered read-only vocabulary, which can be used to produce various texts, i.e. organisms. A genome is like a pattern from which that which is compatible is used. However, since, in addition to the vocabulary, the initial reader (the whole cell) is also inherited (via EIS), the possible innovations or changes in the texts produced are limited.

This also means that, at least theoretically, evolutionary changes and the emergenge of new structures can take place without any differences in individuals' fecundity. (And according to the definition of natural selection, if there are no differences in fecundity, there is no natural selection.)

According to this view, the first things to happen are usually the new choices. A functional circle, searching to supply an organism's need, may stumble upon a new solution. If the interpretational shift can be retained for a long time, for generations, independently of the genome, then the stochastic genetic changes tend to make the shift irreversible. This happens due to the cumulation of mutations in unused parts of the genome. This also means that epigenetic changes precede genetic ones.

Here, we can remind ourselves of the 'Baldwin effect' (according to American psychologist James Mark Baldwin (1896), advocated also by another psychologist Conway Lloyd Morgan, an author of the concept of 'emergent evolution', and paleontologist Henry Fairfield Osborn, an author of the 'organic selection' concept). "The mechanism was based on the assumption that a deliberately chosen new behavior pattern could influence the evolution of a species, but not by means of the inheritance of acquired characters. The body of each animal would adapt itself to the new situation, but instead of this adaptation being directly inherited, it would give the species time during which random variation could come up with truly hereditable equivalents, which would then be favored by selection. Thus, selection need not be the purely mechanistic process condemned by most Lamarckians, but could include a role for the active participation of the organisms themselves" (Bowler, 1992, 81). "This presented habit as the guiding force of evolution - not via Lamarckism, but through its ability to define a trend in bodily structure that would be followed up by natural selection" (Bowler, 1992, 131-132). Recently, this mechanism has found a number of new advocates (Belew and Mitchell, 1996).

The described mechanism of the Baldwin effect provides the possibility for an organism's choice (or organism's search) to be a directing factor in evolution. This may considerably enhance the possible speed of evolution (since there is no need then to wait a whole generation to make the next trial), thus also proposing a solution to the known 'paradox of speed' of evolution.

An important feature of the 'interpretation change' mechanism is that it can take place simultaneously and similarly in many individuals of a population. A usual example where this can occur may be a population's move to a new territory, or an irreversible change in climate or in a resource level, which concurrently influences many organisms. In the case of monophagous insects or fungi, this can be a change in the host species. To give an evolutionary consequence, these changes do not require the appearance of a genotype with higher fitness and the long-term process of out-competing less well fitted genotypes, or even any change in fecundity.

Epigenetic inheritance represents another mechanism which can provide time for stochastic genetic changes to appear and fix the otherwise phenotypic changes, e.g., through the forgetting of the unused. The phenomenon of epigenetic inheritance has, in recent years, progressed to a firmly established biological principle, known, for instance, as genomic imprinting. "Epigenesis, /../ in fact quite ancient in biology, has been underappreciated in the recent past for ideological reasons (specifically, anti-'vitalist' phobias), but it continues to be an indispensable notion" (Anderson, et al., 1990, 758).

It is also interesting to mention that new genetic material comes into the genome mainly from the duplication of pieces of the existing genome. There is a trend for these duplications to become unidentical. Also, the majority of genetic material in eukaryotic cells has more than one copy, which may not be exactly identical. Therefore, for a required function a cell often has the possibility to choose between several slightly different genes (or the products of genes), or to express new genes, which may give almost identical result, but which may also provide possible solutions for new, previously not experienced situations.

The possibility that the organism's interpretational activity plays a role in directing evolution, turns us back to some teleological views which played an important role in evolutionary criticism at the beginning of the century (e.g., Berg 1926), and also those of K. E. v. Baer (1864). However, the concrete mechanism behind this view is somewhat different, or at least understood in a much more detailed way now, as complemented with the current knowledge on the building of living systems and their inheritance systems.

E. Jablonka et al. (1998), whose views I largely share, however, when speaking about the Baldwin effect call this 'a Lamarckian mechanism in Darwinian evolution'. As explained above, this may not correspond to the interpretation of the Baldwin effect and the semiotic mechanism of evolution described here. Evolution can be neither Lamarckian nor Darwinian, but Baerian.

These arguments, hopefully, give some hints for explaining in which way organisms as subjects can influence evolution, including the emergence of new features or new structures, and how the Zielstrebigkeit of evolution may become possible.


References

Anderson, Myrdene (1990); Biology and semiotics; Semiotics in the Individual Sciences; VOL. 1 (ed. W. A. Koch), Universitätsverlag Dr. N. Brockmeyer (pp. 254-281)

Baer, Karl Ernst von (1864); Reden; VOL. 1; Schmitzdorff

Baldwin, James Mark (1896); A new factor in evolution; American Naturalist; VOL. 30 (pp. 441-451, 536-553)

Belew, R. K. and Mitchell, M. (eds.) (1996); Adaptive Individuals in Evolving Populations: Models and Algorithms; Addison-Wesley

Berg, L. S. (1926); Nomogenesis or Evolution Determined by Law; London

Bowler, Peter J. (1992); The Eclipse of Darwinism: Anti-Darwinian Evolution Theories in the Decades around 1900; The John Hopkins University Press

Brauckmann, S. and Kull, Kalevi (1997); Nomogenetic biology and its western counterparts; Lyubischevskie Chteniya 1997; R. V. Naumov, A. N. Marasov and V. A. Gurkin (eds.), Ul'yanovskij gosudarstvennyj pedagogicheskij universitet (pp. 72-77)

Goodwin, Brian C., Sibatani A. and Webster, G. C. (eds.) (1989); Dynamic Structures in Biology; Edinburgh University Press

Gould, Stephen Jay (1977); Ontogeny and Phylogeny; The Belknap Press of Harvard University Press

Jablonka, Eva, Lamb, Marion J. and Avital, Eytan (1998); 'Lamarckian' mechanisms in darwinian evolution; Trends in Ecology and Evolution; VOL. 13, No. 5 (pp. 206-210)

Remmel, Maie (1992); Baer's principles and developmental patterns; Baer and Modern Biology (ed. K. Kull), University of Tartu (pp. 42-44)

Salthe, Stanley N. (1993). Should prediction or historical uniqueness be the central focus of biology? Folia Baeriana; VOL 6 (pp. 247-260)

Uexküll, Jakob von (1937); Die neue Umweltlehre: Ein Bindeglied zwischen Natur- und Kulturwissenschaften; Die Erziehung; VOL. 13, No. 5 (pp. 185-199)

Weingarten, Michael (1993); Organismen - Objekte oder Subjekte der Evolution? Philosophische Studien zum Paradigmawechsel in der Evolutionsbiologie; Wissenschaftliche Buchgesellschaft


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