Synthetic Theory Research Articles

Human evolution.

HUMAN EVOLUTION S. L. WASHBURN* Over the last 25 years there has been remarkable progress in a wide variety of sciences. The impact of the new methods and understandings has brought major changes to the study of human evolution. In a very few years the whole framework of space, time, and the fossil record has been modified. Even the synthetic theory, which seemed so secure a few years ago, is challenged by the neutral theory, and Dobzhansky, Ayala, Stebbins, et al. state that the relative importance of natural selection and stochastic factors "remains the most important unsolved problem in our understanding of the mechanisms that bring about biological evolution" [1, P- 164]. The purpose of this paper is to sketch these developments and to stress that, in my opinion, they are not minor. In one sense the new inevitably builds on the old, and those who do not know history are bound to repeat the errors of the past. But, in a different sense, those who rely too heavily on the past are bound to make the old mistakes. It has not been easy for students of human evolution to escape from the history of their subject. Even today people look to anatomy to settle the problems of evolution. Molecular biology offers far more powerful methods and shows why anatomy could not solve the problem of man's place in nature. The early theories of human evolution were based on comparative anatomy and embryology. Pilbeam has described these theories as "fossil free" [2, p. 7]. There were either no relevant fossils or so few that they exerted little influence on the theories. For example, scientists could not decide whether the original Neanderthal skeleton was a fossil or the remains of a pathological modern human. Major scientists were on both sides of the debate, and it was not until a number of skeletons were found around the turn of the century that most scientists accepted the The author thanks Alice Davis for editorial assistance and the Wenner-Gren Foundation for Anthropological Research for support. *Department of Anthropology, University of California, Berkeley, California 94720.© 1982 by The University of Chicago. AU rights reserved. 003 1 -5982/82/2504-0308$0 1 .00 Perspectives in Biology and Medicine, 25, 4 ¦ Summer 1982 583 Neanderthal as a kind of human being. Even then Neanderthals were described as "uncouth," "repellent," "unattractive," and incapable of fine coordination of the fingers: certainly belonging to a separate species [3]. Elliot Smith and Boule, who shared these views, were leaders in the scientific study of human evolution, and it was many years before Cave and Straus [4] showed that the basic descriptions of the bones had been grossly distorted by the opinions of those describing them. The image of Neanderthal presented to the general public and repeated in book after book was far removed from the actual study of the bones, and it was the image of a primitive, unattractive, and undesirable creature that created the interest in Neanderthal. Hrdlicka's [5] calm description of "the Neanderthal phase of man" could not compete with Boule's dramatic reconstruction. The "fossils" of the 1920s were an odd lot. They included (and I am only considering specimens accepted by major scientists) genuine fossils, mistakes, fragments, fakes, and gross misconstructions. If the early studies had been "fossil free," they were followed by studies which were "nonsense rich." The most careful scientists could not tell which fossils were genuine and well enough preserved to be useful and which were simply misleading. The nonsense-rich era produced futile and often acrimonious debate. In our culture it is customary, when looking back, to consider who was right and who was wrong. Both the fossil-free and the nonsense-rich eras produced theories which were stoutly defended and can only be understood in terms of opinions of times long past. For example, how could anyone accept Piltdown, a modern braincase with an ape'sjaw? This seems impossible today, but wise scientists (Keith and Hooton) accepted it, and other wise scientists (Hrdlicka and Weidenreich) did not. Personal wisdom and scientific training were not enough to lead to useful debate, and the opinions of others were usually dismissed...

The importance of prediction testing in evolutionary biology

It is clear from the above discussion that if I had wished to do so I could have truthfully presented every paper as either testing a prediction, presenting evidence needed in the test of a prediction, or presentin a D-N explanation. (I would not have been able to do this if I had not been sufficiently familiar with the evolutionary literature to recognize what hypotheses were at stake in several of the papers; even when the authors mention the hypotheses they frequently do so only in enough detail to put their paper in context for the knowledgeable biologist.) Since these biologists are working in a period of normal science under the paradigm of the modern synthetic theory of evolution, none of these papers is presented as a test of the modern synthetic theory; but since this theory was used in the derivation of each prediction, each one is a test of it as well as of the hypothesis mentioned. Thus, once we learn to recognize the predictions beneath their cloaks of invisibility, we discover that prediction testing is not, as philosophers have claimed, at best peripheral to evolutionary biology; it is central to evolutionary biology.

Victims of History--A Nonequilibrium Approach to Evolution

Wiley, E. O., and D. R. Brooks (Museum of Natural History, University of Kansas, Lawrence, Kansas 66045; Department of Zoology, University of British Columbia, Vancouver, British Columbia V6T 2A9, Canada.) 1982. Victims of history-a nonequilibrium approach to evolution. Syst. Zool., 31:1-24.-Evolution may be described as a nonequilibrium process involving the conversion of information from one form to another and the maintenance of old or forging of new reproductive networks. Species participate in nonequilibrium processes because they have properties of closure and because evolution is a historically irreversible phenomenon. Speciation is a process which consolidates available potential information into two or more stored information systems. Character change and the history of a clade are highly correlated because potential information is constrained by its own evolutionary history. Thus new and potential information may be converted into stored information only to the extent that this new and potential information is compatible with the ancestral information system or can find expression in an alternate ontogenetic pathway. All modes of speciation as well as anagenesis follow the second law of thermodynamics and may be described by a summary equation which charts the changes of entropy states of information and cohesion over time. We suggest that some empirical evidence corroborates our theory and that the research programs involved in further studying nonequilibrium evolution are largely in place now. [Evolution; nonequilibrium evolution; speciation; entropy; second law of thermodynamics; information theory.] In a previous paper (Brooks and Wiley, 1982), we suggested that evolution is best explained as an irreversible nonequilibrium phenomenon, and not, as present theories describe, as an equilibrium or punctuated equilibrium phenomenon. We suggested nonequilibrium thermodynamics, as developed by Ilya Prigogine and his colleagues (Prigogine, 1947, 1961, 1978, 1980; Glansdorff and Prigogine, 1971; for a readable summary see Prigogine et al., 1972 and Prigogine, 1980). We did so by considering three aspects of populations and species: information specifying successful growth and ontogeny, cohesion resulting from mating bonds between parts of species (i.e., individual organisms), and energy flow. Our application of information theory followed the conceptual developments of Gatlin (1972), Wicken (1979), Ho and Saunders (1979) and Saunders and Ho (1981). We concluded that speciation, the evolution of diversity in a clade, is accomplished by individual species acting as open-ended, closed, thermodynamic systems-open-ended in terms of energy and closed (or partly closed) in terms of information and cohesion. We suggested that our theory is sufficient to explain variation within species and how speciation is accomplished. We also suggested that extinction could be described using the same parameters. In this paper, we take the opportunity to more fully discuss our thesis. We shall not dwell on competing theories such as neo-Darwinism (the synthetic theory) or punctuated equilibrium except where these theories conflict with or illuminate our own. We will say that if the evolutionary process is, indeed, a nonequilibrium phenomenon and if species, like individual organisms, are dissipative energy structures far from equilibrium, then the assumptions of equilibrium inhibit these theories from fully explaining the phenomenon. In spite of this, we predict that neo-Darwinism and punctuated equilibrium (at least as an empirical observation) will come to rest comfortably within our theory.

Beyond Darwinism? The Challenge of Macroevolution to the Synthetic Theory of Evolution

The current theory of biological evolution (the “Synthetic Theory” or “Modern Synthesis”) may be traced to Theodosius Dobzhansky's Genetics and the Origin of Species, published in 1937: a synthesis of genetic knowledge and Darwin's theory of evolution by natural selection. The excitement provoked by Dobzhansky's book soon became reflected in many important contributions which incorporated into the Modern Synthesis relevant fields of biological knowledge. Notable landmarks are Ernst Mayr's Systematics and the Origin of Species (1942), Julian S. Huxley's Evolution: The Modern Synthesis (1942), George Gaylord Simpson's Tempo and Mode in Evolution (1944), and G. Ledyard Stebbins’ Variation and Evolution in Plants (1950). It seemed to many scientists that the theory of evolution was essentially complete and that all that was left was to fill in the details.

Brain Laterality In Signed, And Spoken Language: A Synthetic Theory Of Language Use*

(1982). Brain Laterality In Signed, And Spoken Language: A Synthetic Theory Of Language Use* Journal of Visual Verbal Languaging: Vol. 2, No. 2, pp. 17-36.

Brain Laterality in Signed and Spoken Language: A Synthetic Theory of Language Use

First, the hypothesis is examined that right hemispheric cognitive processes underlie human language in a fundamental way, and specifically, that the right hemisphere is implicated in the semantic processes underlying the establishment of meaning and in processing of linguistic “gestalts” generally. In this respect, several lines of evidence are examined, including the performance of aphasics, commisurotomy patients, native deaf signers, and users of Japanese and Chinese ideographs. A right hemispheric basis for various aspects of language use having been established, a second hypothesis is examined: that differences in societal complexity are related to differences in relative dependence upon cognitive processes controlled by the right and the left cerebral hemispheres. More specifically, we examine the hypothesis that growth in societal complexity has been accompanied by increased dependence upon left hemisphere processes. We present quantitative evidence from studies of differences in language structure to support the hypothesis. More broadly, what we are attempting here is to construct a synthetic theory of language use that incorporates information from the neurological and the social sciences.

Is a New Evolutionary Synthesis Necessary?

The current (synthetic) theory of evolution has been criticized on the grounds that it implies that macroevolutionary processes (speciation and morphological diversification) are gradual. The extent to which macroevolution is gradual or punctuational remains to be ascertained. Macroevolutionary processes are underlain by microevolutionary phenomena and are compatible with the synthetic theory of evolution. But microevolutionary principles are compatible with both gradualism and punctualism; therefore, logically they entail neither. Thus, macroevolution and microevolution are decoupled in the important sense that macroevolutionary patterns cannot be deduced from microevolutionary principles.

Evolution: A System Of Theories

EVOLUTION: A SYSTEM OF THEORIES* RALPH W. LEWISt The many theories in biological evolution are usually presented in a narrative form that fails to give adequate attention to the structure of the theories discussed and to the relations between them. This paper is a preliminary attempt to describe some aspects of theory structure and some kinds of relations between theories found in the study ofevolution. The paper does not attempt to give a complete or well-rounded view of evolution, but I do assume that the patterns discussed and the postulate lists given in the Appendix are an initial step in the presentation of the whole of evolution in a more concise, complete, and logical order. Knowledge in most disciplines is grouped into areas of thought called theories that are built on the pattern of Euclidean geometry. When theories are partially formalized to show some of this pattern explicitly, the intra- and interworkings of theories become more clearly visible, and the total structure of the discipline becomes more evident. When this view is applied to the study of evolution, we find hundreds of theories which have the typical geometric form, albeit the form is often obscured. And we find relations between theories that permit them to be characterized by one or more of these terms: major theory, subtheory , accessory theory, parallel theory, competing theory, and subsumed theory. In this paper only the first three will be discussed. The two major theories in evolution as developed by Darwin are the theory of descent with modification and the theory of natural selection. By the use of the gene theory as an accessory theory, modern biologists have refined and modified natural selection theory to produce what is called the synthetic theory. The postulates of the major theories and several subtheories are given to support the views of the author and to permit the reader to judge *The author thanks Rollin H. Baker, Paul H. Barrett, Alain F. Coreos, Anton E. Lawson, William S. Moore, and a reviewer for their many suggestions and corrections. t Professor, Department of Natural Science, Michigan State University, East Lansing, Michigan 48824.© 1980 by The University of Chicago. 0031-5982/80/2304-0149$01.00 Perspectives in Biology and Medicine · Summer 1980 | 55 1 them. The views of both author and reader are bound to remain tentative until the postulate lists are corroborated or corrected by the best scholars and until the lines of reasoning used by biologists to construct and test the theories have been studied in greater detail. But even in the present tentative state some readers may agree with me that partial formalization of theories can simplify and clarify our knowledge of evolution . The theses in this essay were initiated or supported by the views of many scholars. The words of three of them are a good introduction for some of the arguments that follow. "The progress made in recent decades in the development of unifying concepts has been so great, however, that the presentation of chemistry to students of the present generation can be made in a more simple, straightforward, and logical way than formerly" (Linus Pauling [1, p. viii]). "[Ancient Greece] for the first time created the intellectual miracle of a logical system, . . . , —Euclid's geometry. This marvelous accomplishment of reason gave the human spirit the confidence it needed for its future achievements" (Albert Einstein [2, p. 82]). "Our understanding ofevolution depends on a combination of clearly formulated theories and wide comparative knowledge" (John Maynard Smith [3, p. 241]). The pattern of the Euclidean logical system prevades every theory in every discipline, but only in mathematics and physics is the pattern often made explicit. With some exceptions, the other disciplines expand their theories discursively to such a degree that it is often difficult to identify the basic premises, the postulates, of each theory. And when these are not clearly stated, the reasoning that flows to and from the postulates is cloudy and the subject is needlessly obscure. Only when each discipline makes explicit its Euclidean logical systems, as far as this is practicable, will man be able to teach, learn, use, and enlarge his knowledge with maximum efficiency. Suppes [4] has argued convincingly for...

Functional Morphology of the Vertebrate Visual System An Essay on the Evolution of Complex Systems

The existence of complex organ systems has always been a serious challenge to the synthetic theory of evolution. This essay considers two aspects of the problem in the case of the vertebrate visual system. The first is how to resolve the visual system into structural components which can be related to evolutionary processes. I use the visual system of the red-eared turtle Pseudemys scripta elegans to illustrate how a neural system can be decomposed into three nested levels of organization. The first level consists of individual neurons . Analysis at this level considers the types of neurons which are present and the interactions which occur between them. The second level consists of groups of neurons called modules . They form a unit structure which is repeated throughout some particular region of the system. The third level consists of a network which is composed of aggregations of neurons (nuclei) which are interrelated by bundles of axons. Several projections converge upon modules in many of the nuclei. The second aspect is the extent to which the vertebrate visuil system cin be accommodated into the synthetic theory. Analysis of genetic abnormalities provides evidence that some aspects of visual system structure are under genetic control. Analysis of variations in visual system structure indicates that interspecific variations occur frequently, particularly at the lower organizational levels. Serious difficulties arise however in attempts to establish causal relationships between visual system structure and the organisms behavioral adaptations. These difficulties stem from applications of the neurological concept of the localization of function. The available evidence is then, consistent with the hypothesis that the visual system evolved in accordance with the synthetic theory. It remains however, to establish more clearly the rehtionship between visual system structure and environmental demands.

An immunologically derived contribution to the “synthetic theory of evolution”

An immunologically derived contribution to the “synthetic theory of evolution”

Anthecology: Old Testament, New Testament, Apocrypha (Banquet Address, 8 February 1979)

Abstract The development of anthecology, with an emphasis on pollination ecology, is surveyed, using less-often cited literature. The Old Testament of anthecology was written at the end of the nineteenth century; the New Testament began to be assembled after the rise of the Synthetic Theory of Evolution (“Neo-darwinism”) in the 1940s. Differences between the Old and the New anthecology are discussed and particular attention is given to the new emphasis on tropical anthecology. Apocryphal writings are to be found in all the literature periods; some of them have led to important developments and others may do so. Particularly with the prospect of serious development of the anthecology of ecosystems, it is suggested that amateur botanists can make a contribution to the New anthecology comparable to their influence on the Old.

Symbionticism revisited: a discussion of the evolutionary impact of intracellular symbioses.

Wallin (1927) first published the notion that the fusion of bacteria with host cells was the principal source of genetic novelty for speciation. He suggested that mitochondria are transitional elements in this process. While the significance that he attributed to symbiosis now seem excessive, he was one of the first authors to be aware of the evolutionary potential of symbiotic events and his view of mitochondria may not seem strange to many cell biologist today. The most significant evolutionary development which has been attributed to intracellular symbiosis is the origin of eukaryotic cellular organization. The current status of the 'serial endosymbiosis hypothesis' is briefly review. The case for the symbiotic origin of the chloroplast, based principally on 16 S RNA oligonucleotide cataloguing, is very strong. Mitochondrial origins are more obscure but also appear to be symbiotic due to recent 18 S cataloguing from wheat embryos. The probablility of the multiple origin of some eukaryotic organelles is also examined, the processes in question being the acquisition of distinct stocks of chloroplasts from disparate photosynthetic prokaryotes and the secondary donation of organelles from degenerate eukaryotic endosymbionts to their hosts, with specific reference to the dinoflagellates Peridinium balticum, Kryptoperidinium foliaceum and the ciliate Mesodinium rubrum. It is concluded that the evolutionary potential of intracellular symbiosis ('cytobiosis': a term introduced in this paper) is great, with the best established influence being on the origin of eukaryotic chloroplasts. Together with the potential effects of viral vectors, symbiosis serves as a supplementary speciation mechanism capable of producing directed evolutionary changes. It is likely that these processes will explain some of the apparent anomalies in evolutionary rates and direction which are not readily explicable by the conventional synthetic theory of evolution.

The value of the new-born calf in evolutionary studies

Living organisms possess, as attributes, many and differing patterned, structural and behavioural systems. These systems are not self-sufficient and must be complemented by items from outside themselves in order that success in completion of life-history is achieved. Potentially complementing items are many and multifarious so the incipient species has, as it were, a wide choice. As examples of successful complementing, the alimentary system is complemented by food and water, the respiratory system is complemented by free oxygen, the locomotor system of land animals by the solid-earth surface, of aquatic animals by water and of aerial animals by the atmosphere. In the new-born calf we have a highly developed animal, which is transferred suddenly from an intrauterine environment to a free one. Its first action is to complement its respiratory system by breathing air. Its innate postural changes in reaching the standing posture from the recumbent are complemented by the earth’s firm surface, as is also the innate urination posture adopted by the calf on the occasion of its first urinating postnatally. By being innately attracted to a large moving object and showing thigmotaxic responses towards that object, it eventually finds the site of its dam’s udder and thereby a source of food which complements its alimentary system. Also, play and curiosity are complemented by items in the environment. In addition to these behavioural patterns are structural patterns, shown by the reticulum and the omasum, both of which are present in the new-born calf and thus present before being complemented. The above attributes and their complements are common to all calves, and so are specific and primary; variations are shown to be secondary. Darwin’s theory of natural selection of indefinite variations and the present-day synthetic theory, based on selection of genes, omit consideration of specific characters and their complements and so are grossly defective. THE QUESTION OF ANIMAL AWARENESS

In quest of “natural man”: Human behaviour and design

It is argued that the need for a truly synthetic theory of human sociospatial behaviour relevant to the design professions has been heightened by the rise of technology and rapid urbanization. Impediments to the development of such a synthetic include the widely differing perspectives and levels of maturity achieved by various branches of the behavioural sciences; specific problems and controversies are illustrated from the literature. Greenbie's recent attempt at a synthesis for “design for diversity” is critically reviewed and evaluated as a conceptual catalyst.

Testability, disreputability, and the structure of the modern synthetic theory of evolution

Testability, disreputability, and the structure of the modern synthetic theory of evolution

A Systems-Analytical Approach to Macro-Evolutionary Phenomena

Two sets of evolutionary phenomena find no explanation through current theory. For the static phenomena (such as homology, homonomy, systematic weight, and "Type") there is no causal base, although these principles are responsible for all phenomena of predictable order in the living world. The dynamic phenomena (such as homodynamy, coadaptation, parallel evolution, orthogenesis, Cartesian transformation, typostrophy, hetermorphosis, systemic mutation, and spontaneous atavism) have no causal explanation, although they are responsible for all directed phenomena in macroevolution. These phenomena share one unifying principle which can be explained by a system theory of evolution based on, but extending, the current synthetic theory. This system theory envisages feedback conditions between genotype and phenotype by which the chances of successful adaptation increase if the genetic units, by insertion of superimposed genes, copy the functional dependencies of those phene structures for which they code. This positive feedback of the adaptive speed (or probability) within a single adaptive direction is compensated by negative feedback in most of the alternative directions. The negative feedback operates as selection not be environmental but by systemic conditions developed by the organization of the organism. The consequences are an imitatively organized system of gene interractions, the rehabilitation of classical systematics, the reality of the "natural system," and, in general, the resolution of the contradiction between neodarwinists and their critics, between reductionists and holists, between "a priori" and "a posteriori" views, between idealism and materialism, and between the notions of freedom and of purpose in evolution.

Universal projective geometry via topos theory

The idea of this article is that linear algebra and projective geometry over a local commutative ring is equivalent to intuitionistic linear algebra and intuitionistic pure projective geometry over a field (at least in so far as caherenr sentences are concerned; this term will be explained). By pure projective geometry is meant a formulation of synthetic geometry in terms of the predicates “incidence” and “equality” alone, in contrast to formulations which include a special apartncss predicate. Heyting’s intuitionistic projective geometry, for instance, has such an apartness predicate o, and it is also necessary to have such w if one wants to formulate a reasonable synthetic theory for the projective geometry over a local ring. There are probably other and better reasons for looking for the “projective geometry over a local ring” than the one which gave rise to the present research: Study’s transfer principle. It says that whatever is true in plane projective geometry over the ring of dual numbers D = R[E] (with E’ = 0), can be reinterpreted as a theorem about the set of lines in euclidean 3-spL.:e. see e.g. [C;). This set (which is a 4-dimensional manifold) is thereby made into a Hjelmslev plune; Hjelmslev used this fact. Of course, the value of the transfer principle is that one gets, or hopes to get, theorems for the projective plane over D ;~y “analogy” with the well-known projective geometry over R. We are stud;% ig the meta-mathematics of that “analogy”.

Observed and expected variation in hominid evolution

All of the major groups of fossil hominids (australopithecines, pithecanthropines, Neandertals, and early sapiens) were discovered by 1925, and therefore prior to the formulation of the synthetic theory of evolution that revolutionized the concept of the species in systematics. While these fossil finds were being made the framework for their interpretation included several assumptions: (1) that the number of living hominoid species was great, and that intraspecific variation was slight (authoritative sources recognized as many as 14 separate species of chimpanzees and 15 species of gorillas); (2) that the timescale of human evolution was brief (measured in tens or hundreds of thousands of years). As a result of these premises the consensus that hominid evolution was characterized by a large number of sympatric and synchronic species was virtually inevitable. In contrast, recent molecular studies demonstrate that genetic diversity among recent hominoids is so slight that even humans and chimpanzees differ at only about 1% of the loci that have been sampled so far; evidently, very small genetic differences can produce rather great contrasts in morphology. At the same time, geological break-throughs have increased the timescale for human evolution to several million years. It is concluded that morphological differences among fossil hominids, even if very appreciable and complex, do not necessarily reflect a great degree of either genetic or taxonomic diversity. Potential effects of evolutionary change through time should be incorporated into models of hominid evolution as a means of assessing the minimum number of lineages required to account for observed variations among hominid specimens.

Hypersurfaces of Order Two

A hypersurface ${S^{n - 1}}$ of order two in the real projective n-space is met by every straight line in maximally two points; cf. [1, p. 391]. We develop a synthetic theory of these hypersurfaces inductively, basing it upon a concept of differentiability. We define the index and the degree of degeneracy of an ${S^{n - 1}}$ and classify the ${S^{n - 1}}$ in terms of these two quantities. Our main results are (i) the reduction of the theory of the ${S^{n - 1}}$ to the nondegenerate case; (ii) the Theorem (A.5.11) that a nondegenerate ${S^{n - 1}}$ of positive index must be a quadric and (iii) a comparison of our theory with Marchaud’s discussion of “linearly connected” sets; cf. [3].

Hypersurfaces of order two

A hypersurface ${S^{n - 1}}$ of order two in the real projective n-space is met by every straight line in maximally two points; cf. [1, p. 391]. We develop a synthetic theory of these hypersurfaces inductively, basing it upon a concept of differentiability. We define the index and the degree of degeneracy of an ${S^{n - 1}}$ and classify the ${S^{n - 1}}$ in terms of these two quantities. Our main results are (i) the reduction of the theory of the ${S^{n - 1}}$ to the nondegenerate case; (ii) the Theorem (A.5.11) that a nondegenerate ${S^{n - 1}}$ of positive index must be a quadric and (iii) a comparison of our theory with Marchaud’s discussion of “linearly connected” sets; cf. [3].