Human evolution theory utilizing concepts of neoteny & female sexual selection
An etiology of neuropsychological disorders such as autism and dyslexia, and the origin of left handedness.
We are presenting a theory that suggests that the same fundamental forces can be observed to operate across many different disciplines. A history of how those forces have evidenced themselves in the work of previous researchers and theoreticians will make it possible to understand that revolutionary nature of the theory which reveals hitherto unrecognized patterns that operate across different disciplines. As we describe patterns and relationships unfamiliar you, we follow the paths built by our predecessors that lead to our unconventional conclusions. In other words, this theory, shift theory, is not a revolution as much as it is a realignment. It is not unlike taking the notes, the harmonic patterns, and the musical instruments of symphonic forms and using them to create a new form such as jazz. The same, yet, very, very different.
Scores of authors have made previous connections that we claim and utilize in this work. Almost no portion of our work is wholly original. What we have to offer is a wholly new way of assembling and composing elements formerly unconnected. The music of our pages is filled with the melodies of other thinkers. For example, this concert would never have occurred but for works of Stephen J. Gould and Norman Geschwin. These two researchers created, for us, the bridge to evolutionary biology and neuropsychology, respectively. It is these two disciplines that have informed our (we believe) special understanding of species evolution, human evolution and the transition to culture.
In this first section, through chapter 7, we will follow the work of evolutionary biologists and researchers and theoreticians in related fields and the unfolding of evolutionary theory. In the next section specific theories of hominid evolution will be examined and explored as we describe how shift theory cooperates or contrasts with the established paradigm. Next we will explain how culture manifests the principals that we will have established in our first two sections. Next, we describe how the etiology - the structure and origin of several diseases and conditions are understandable using these new theoretical tools, and how these diseases might be prevented and symptoms decreased. Section V summarizes this work.
While discussing a history of evolutionary biological theory we will be teasing out our four interconnected principal themes from the works of our predecessors. These four strands are: 1) environmental influences 2) selective processes 3) hormonal intermediaries and 4) the revision of rates and timing of maturation rates. We will explore four additional areas as we work our way forward through the decades. First, we will linger upon those theories hypothesizing the trans-disciplinary manifestation of evolutionary processes, theories predating our own. We are not the first to see an evolutionary theory manifest itself in several seemingly unrelated areas. Second, we feel compelled to pay closer attention to those individuals for whom the devising of a theory was accompanied by anomalous experience. Anomalous theorizing (theory creation accompanied by unconventional experiences) seems as compelling, to us, as those specific anomalies that lead us toward this new paradigm. It was by following a trail of anomalies that wends its way through different disciplines that we were lead to the theory that you now read. Third, we will examine the varying selective processes as they appear in the history of evolutionary theory for their relationship to each other. Emphasis over the last seventy years on natural selection has overlooked not just alternative forms of selection, such as sexual selection, but how one selective process may have selected for - given birth to - another. Fourth, the work of Charles Darwin will be scrutinized as a source for almost every important theoretical innovation that this work offers. In section IV we will use Darwin's innovations to form a foundation for an understanding of disease.
A deep paradox lies at the foundation of evolutionary theory. Somebody (I can't remember who it was though it was probably Gregory Bateson) said behind every paradox is an unexamined presupposition. Descartes' revelation -- it was nothing less than a revelation, he believed that the vision and then the dream that told him the revelation came directly from God -- was that the human body and the human mind were separable. Descartes believed God had communicated to him that the material world could be broken down, reduced, into observable components whose natures could be understood by observing their relationships with their neighbors. Descartes had an experience, an experience that was not communicable to another person -- he could not prove it-- that told him that only communicable and/or reproducible experiences were to be designated as information usable in the new paradigm. Descartes' God told him to only believe what his senses told him except in this case of God's telling him that this is, in truth, the case.
Science rests firmly on this paradox. Revelations at the root of scientific discovery occur repeatedly through the ages. Somehow we forget the relativistic foundation of our modern beliefs. We take ourselves very seriously, forgetting that an experience of feeling part-of-something-larger-than-the-self has accompanied modern researchers for hundreds of years. In other words, the forces of intuition are alive and well. The Muse speaks though she is called by other names. The reductionist, materialistic foundations of modern science have deeper roots, and those roots go back before the days when people believed that only what could be measured, needed to be understood.
Descartes created the foundation for modern science. He established that we could have confidence that the world was understandable, that it had structure, and that this structure could be understood in the form of the patterns of cause and effect relationships.
Before Linnaeus, John Ray ( years) established that there was evidence in the earth, through fossils remains, that suggested the existence of extinct species. In addition, Ray identified that there were patterns ranging though the flora and fauna of contemporary times that suggested connections that could be identified and categorized. Yet it was Carolus Linnaeus (1707-1778), a Swedish botanist that nourished the roots of evolutionary theory and invented the conceptual instruments that made possible the work of the composers of concepts that would follow.
Linnaeus observed that there was specific pattern inherent in the structure of biological life. Linnaeus and his followers proceeded to discern the order or interrelationships of those patterns. He began to understand that there might be a relationship between species developed over time (Eiseley, 1958). Though publicly unwilling to consider the possibility of species metamorphosizing into others species over time, by the end of his career it becomes clear, by the passages he began deleting from his writings, that these were ideas he was entertaining.
Charles Bonnet (1720-1793), with an artist's heart, forged a scientific theory that managed to bring together the religious demands of the 18th century with a materialist's belief that there be congruency in explanation and sensory experience. Stephen J. Gould (1977) makes evident the near impossible conditions that forged the logic of Bonnet's theory of life, the platform that all theories of evolution that followed were to build upon.
Two of Bonnet's theories are key to the concerns of this short history, because they informed the work of the theorists that we, in our time, can more easily relate to. The first of these, Bonnet's theory of preformation, states that all life springs from miniature versions of adult selves (though not easily discernable in its clumpy, still not fully formed, embryonic state) that were once inside a parent, inside a grandparent, back to the creation week and Adam and Eve. Bonnet's vision estimated that no space was too small to hold all ancestors going back those few thousand years. He closely observed embryo ontogeny to conjure his hypothesis.
Closely tied to preformation was Bonnet's theory of the chain of being or universal chain in which every creature on the globe had its place in a hierarchical ladder from asbestos to human beings. As in the preformationist life within life within life, in the theory of the chain of being all life was created at the same time, some 6000 years ago. For over 100 years into the growth of evolutionary theory these two theories were the template upon which evolutionary principles were formed.
The story of evolutionary theory truly begins with the Comte de Buffon (1701-1788). Eiseley (1958) outlines several patterns that Buffon was able to isolate; patterns integral to a syntheses that presupposes the existence of biological evolution, whether by natural selection, the inheritance of acquired characteristics, or another solution. The patterns are 1) life is generated in greater profusion that can be supported over time (what Darwin and Wallace drew from Malthus's work) 2) life is produced in great variety, variety inheritable by an organism's descendants. 3) there is relationship between similar structures in different species. 4) dramatically increased time is a variable offering solutions to the anomalies unexplainable by the 6,000 year old history suggested by the Bible. 5) species have become extinct. 6) relationships between species might be able to be discerned by conducting breeding experiments.
Buffon's ideas come across like the melodies and riffs an orchestra might generate in the space of time before the conductor raises his or her baton. An order had not yet been established, but the patterns were in play. Evolution as a theory was now a consideration. It was being discussed, in the late 18th century, among those familiar with the patterns that Buffon and others had observed. What would later develop into the fields of evolutionary biology, embryology (Haeckel, 1897) and geology (Eisley, 1958) were, in the 18th and early 19th century, the observation of different levels of experience noted to have patterns in common, specifically patterns that supported the suggestion of the passing of a great deal of time.
Buffon put forth a specific definition of species which, once established, made it easier to conceptualize the relationship between one species and another.
"We should regard two animals as belonging to the same species if, by means of copulation, they can perpetuate themselves and preserve the likeness of the species; and we should regard them as belonging to different species if they are incapable of producing progeny by the same means. Thus the fox will be known to be a different species from the dog, if it proves to be the fact that from the mating of a male and a female of these two kinds of animals no offspring is born; and even if there should result a hybrid offspring, a sort of mule, this would suffice to prove that fox and dog are not the same species -- inasmuch as this mule would be sterile." (Boorstin, 1983)
By applying the tools of Descarte to the earth, its history, biology, geology, and the relationship between these different areas, Buffon would invent explanations based upon processes evidently operating in present time. Relying upon the information brought to him through his own senses, Buffon could imagine how these same events could effect the unfolding of the earth and its inhabitants over time. Buffon helped invent geological time. He estimated that the earth may have been exposed to the natural forces for anywhere between 78,000 and 3 million years. He considered that a single species might evolutionarily diverge into a number of species (Bowler, 1984). But his primary conjectures focussed on spontaneous generation and a fixity of species.
With Buffon begins an attention to the environment as having an influence on species over time, responsible in some way for evolution. Other theorists, such as Maupertuis publishing the Venus physique in 1745, suggested that species were not fixed, and that the environment may, in some way, be compelling species to change over time (Bowler, 1984). But it was Lamarck who devised a theory that, he believed, explained the origin of species.
Jean Baptiste Lamarck (1744-1829) is believed to be the author of the first published account of a theory of evolution, though there is some controversy over whether his ideas were first propounded by Charles Darwin's grandfather, Erasmus Darwin (Butler, 1882; Eisley, 1958). In 1809, he detailed his ideas in his, Zoological Philosophy though these ideas first appeared in lectures in 1801 and 1802 (Corsi, 1988). Lamarck's theory marks the appearance of the first clear suggestion that environmental influences might be responsible for individual adaptations and that it might be possible to pass on those adaptations to progeny resulting in an evolution of species. The environment forces individual members of species to behave in ways contrary to their established habits. By repeatedly engaging in those new specific activities, through the use or disuse of organs, those individuals create a predisposition for their progeny to succeed in those actions, whether behavioral or morphological. Individuals and their progeny, by adjusting to changing environmental demands (Gottlieb, 1992: Eisley, 1958), by the use or disuse of organs cause the species to evolve. Lamarck was clear that the passage of a great deal of time was necessary for the unfolding of evolution in response to environmental influences (Eisley, 1958). This idea that joins Buffon's and Hutton's beliefs that confidence in a vast scale of time is necessary to explain anomalies of the earth, structures unexplainable by the religious creationist interpretations of the natural world.
The idea that evolution might progress according to the ability of species to acquire features based on use and disuse, compelled by environmental change, was not original to Lamarck. While not a widespread belief, it was common among his colleagues. Yet Lamarck was the first to cogently communicate how this process could unfold.
"It seems, as I have already said, the time and favourable circumstances are the two principal means which nature uses in creating all its products. We know that time has no end for it, and is consequently always at its disposal. ... As to the circumstances of which it has need, and which it still uses all the time to change its productions, one can say that they are in effect inexhaustible. The main circumstances are derived from the influence of climate; changes in the temperature of the atmosphere and of all the environment; from the variety of places, of habits, movements, actions; and lastly form the variety of modes of life, conservation, defence, multiplication, etc. etc. Now consequent upon these different influences the faculties are widened and strengthened by use, they are changed by new habits maintained for a long time; and gradually the conformation, consistence, the nature and state of the parts of organs, affected by the results of all these influences, are conserved and are spread by reproduction."(Lamarck, JB, 1809)
The example most often quoted from his work is that of the giraffe. He also uses shore birds to explain his theory.
"It is interesting to observe the result of habit in the peculiar shape and size of the giraffe (Camelo-paradalis): this animal, the largest of the mammals, is known to live in the interior of Africa in places where the soil is nearly always arid and barren, so that it is obliged to browse on the leaves of trees to make constant efforts to reach them. From this habit long maintained in all its race, it has resulted that the animal's fore-legs have become longer than its hind legs, and that its neck is lengthened to such a degree that the giraffe, without standing up on its hind legs, attains a height of sex metres (nearly 20 feet). " (Lamarck, JB (1984 (1809)) Zoological Philosophy: An Exposition with Regard to the Natural History of Animals. Univ. of Chicago Press, Chicago p. 122)
"We find in the same way that the bird of the water-side which does not like swimming and yet is in need of going to the water's edge to secure its prey, is continually liable to sink in the mud. Now this bird tries to act in such a way that its body should not be immersed in the liquid, and hence makes its best efforts to stretch and lengthen its legs. The long-established habit acquired by this bird and all its race of continually stretching and lengthening its legs, results in the individuals of this race becoming raised as though on stilts, and gradually obtaining long, bare legs, denuded of feathers up to the thighs and often higher still." (Lamarck, JB (1984 (1809)) Zoological Philosophy: An Exposition with Regard to the Natural History of Animals. Univ. of Chicago Press, Chicago pp. 119-120)
By depicting the process whereby the habits generated by environmental change can lead to physiological changes inherited by the next generation, Lamarck would have suggested that variation is not random. His laws one and two (Lamarck, 1909), make clear that it is the passing on of acquired features that propels the evolutionary process. In addition, Gottlieb (1992) makes clear Lamarck's strong allegiance to behavior as an intermediary between environmental influence and hereditary adoption of the behavioral becoming physiological features, that is the engine behind evolutionary change. Last, Lamarck (1909) emphasizes, as did Buffon, that a great deal of time is required for this process to unfold.
"Everything then combines to prove my statement, namely: that it is not the shape either of the body or its parts which gives rise to the habits of animals and their mode of life; but that it is, on the contrary, the habits, mode of life and all the other influences of the environment which have in course of time built up the shape of the body and of the parts of animals. With new shapes, new faculties have been acquired, and little by little nature has succeeded in fashioning animals such as we actually see them." (Lamarck, (1809)
In one fascinating passage, Lamarck notes relationships he had observed between domesticated and wild animals of the same species. Fifty years later, Darwin would begin his explanation of the dynamics of natural selection by attending to these same issues. Where Darwin cogently describes how humans select from features randomly generated to get the desired features in their livestock, dogs and pigeons, Lamarck specifies how the environment generates features according to the habits, use or disuse of specific organs, of the animals domesticated.
Like Bonnet's universal chain, Lamarck believed that God had created a chain toward perfection (Spencer, 1898) with humans at the zenith, a belief shared by almost all his predecessors and most of his contemporaries. Eiseley (1958) describes Lamarck's view as an escalator rather than the traditional ladder in the established belief of a chain of being toward perfection. The environment could create detours away from this natural predisposition toward perfection, and the evidence of species variation were examples of this environmental influence. Continual spontaneous generation was how Lamarck explained the enormous diversity across the span of living creatures. He did not believe life evolved from a single ancient creature.
As noted, the invention of the chain of being theory is credited to Charles Bonnet (Gould, 1977). Bonnet also suggested that individuals acquired individual characteristics during their growth in the uterus where the preformed embryo was subject to the influences of the uterine environment (Bowler, 1984); a theme that would be later echoed by Mivart.
Alternatives and variations on Lamarck's views began to emerge after his theories developed a following among his associates in France (Corsi, 1988). One evocative alternative was from Geoffroy St-Hilaire (Blacher, 1982). St-Hilaire proposed that use and disuse or the habits of plants and animals did not influence evolution. Only the environment, acting directly on species, compelled species to evolve. St-Hilaire may have been the first to identify that human beings evidenced a certain developmental regression, later characterized as neoteny (by Kollmann in 1885). When first noticed by St-Hilaire, as arrested development (Gould, 1977), he focussed on the human brain as continuing to grow with a speed characteristic of the infants of species.
Lamarck made a number of visionary conjectures including his suggestion that humans may have developed language through the use of hand gestures bridging later into words (Corsi, 1988), and hypothesizing that humans evolved from ape-like progenitors, perhaps the orangutan (Bowler, 1984).
Lamarck established the environment as the major factor responsible for the evolution of species. He was more specific, for example, he suggested temperature was an influential variable, but he offered no clearly defined selective processes to explain how the environment actually generated change. His hypothesis of liquid channels creating change offered no experimental paths. Most studies conducted over the next century and a half (Batcher, 1982) offered few results that could support his hypothesis that use or disuse could drive evolution. Yet, within fifty years of Lamarck's death many "neo-Lamarckians" would support Lamarck's conjectures that the generation of individual features would be environmentally related and non random in nature (and believed that they had evidence of this process). Lack of a hypothesis that could be experimentally supported to explain the evidence eventually made Lamarckism an unpopular cause.
Karl Ernst Von Baer (1792-1876) was not only a seminal thinker in the origin of embryology. He formed conclusions at the very birth of this science that were decades, even a hundred years ahead of their time with insights applicable to embryology, evolutionary biology, and paleontology. Moreover, he made made important contributions to anthropology, ecology and geology (Gould, 1977).
Paving the way for Von Baer's work were the discoveries of Friedrich Wolff (1733-1794). Though not recognized when first published in 1759 (Haeckel, 1897), Wolff's studies of chick embryos eventually undermined the conventional wisdom that all life unfolds from miniature animals and plants already inside the parents at the time of their conception; miniatures received from their parents, and they from their parents, like Russian dolls, all the way back in time to the week of Adam and Eve's creation. Wolff did not find a miniature chicken in a chick embryo, but discerned a succession of stages, always in the same sequence, from an undifferentiated beginning to a clearly demarcated end (Gottlieb, 1992). From this beginning,Von Baer would go on to characterize the relationship of the stages of growth, that Wolff established, to species across the animal spectrum.
Von Baer established the context in which theoreticians in a dozen disciplines would set up their concepts. His ground breaking observations were not disputed, though his interpretations often were. Yet Von Baer's interpretations have stood the test of time (Gould, 1977) and are now the conventional wisdom of both neo-Darwinist and alternative evolutionary theories.
Ueber Entwickelungsgeschichte der Thiere was published in two volumes in 1828 and 1837 (Haeckel, 1897) In this work Von Baer followed the course of embryological development from conception to maturity in a number of different species (Gottlieb, 1992) both vertebrates and invertebrates (Haeckel, 1897). He formed conclusions summarized in the following four laws (Gould, 1977). 1) The earlier the ontogeny, the more general the features. 2) Specific features develop from the general over the course of ontogeny. 3) Each embryo, as it develops, increases its distance from other species becoming more specialized in its own idiosyncratic direction. 4) Any "higher" species is not, at any stage, like the adult of a "lower" animal, but may be like the lower animal's embryo. Gould (1977) summarizes Von Baer primary contribution as follows....
"Since evolutionary classification depends upon the identification of homologies linking diverse animals to common ancestors, von Baer's laws state a basic principle in phyletic reconstruction: "Community in embryonic structure reveals community of descent."
Von Baer fought a particular interpretation of his work, that ontogeny recapitulates phylogeny, promulgated most assiduously by Haeckel (Gould, 1977). Haeckel believed in recapitulation, that species evolved by the adding on of features as adults, features that were then carried backward though ontogeny as a species differentiated during evolution. Haeckel ignored exceptions to his dynamics such as the theories which espoused the potential power of evolutionary change coming from revisions of growth patterns generated at the zygote creation level, or during embryogenesis in the uterine environment. Von Baer focussed on the evidence of his observations, unsupportive of suppositions that hypothesized that evolution was totally dependent on selective processes influencing the adults of species.
Cuvier laid the foundation for theories of species transformation or evolution He soaked up the scientific and philosophical trends of his time (Eiseley, 1958), observing closely the structures of living forms, and applying his insights across disciplines while staying a strong proponent of fixity of species.
Cuvier maintained a severely non-hierarchical orientation when addressing the relationship between species. He emphasized that function dictates form at all levels; both within species and across species (Gould, 1977). He believed that there is a perfect balance suggested by the exact purpose of every animal feature. Each feature within an animal is separately complemented to its function, unrelated to any hierarchical positioning in its creation according to either creationist or transformational hypotheses. Cuvier's insisted upon a non-hierarchical relativistic view that in many ways predates how species are understood today (Bowler, 1984).
In addition to believing that each feature has its exact purpose, Cuvier established that every element in the physiology of an individual is closely linked to that individual as a whole, and that knowing in detail the function of parts creates the opportunity to intuit the whole from the part (Eiseley, 1958). In other words, by examining detail, the nature of the larger structure can be discerned.
Moreover, on an across species scale, Cuvier was able to link related species to one another and form larger patterns that suggested the branching relationships between species as opposed to a fixed hierarchy (Eiseley, 1958). Almost paradoxically, to our 21st century ears, Cuvier hypothesized a closely connected webbing of species based on relationship of form while rejecting evolution. Cuvier favored a fixed or stationery view that presupposed that there was no transformation from one species to another.
The principal that supported Cuvier's unique synthesis was his theory of cataclysms that proposed that life on earth occurred in the creations which followed a series of violent destructions (Haeckel, 1897) which were characterized by the total elimination of life on earth several times. Rather than evolution, there was a series of cataclysmic creations, each species formed to fit perfectly the function of its niche, each niche fitting perfectly into the whole.
Cuvier's unique perspective offered him insights on the relationship between the parts and wholes of individual species, and the relationship between species. His observations of the lifeforms of the present day provided him with the theoretical tools on which to found paleontology. Able to establish a fossil chronology based on his diggings in France (Eiseley, 1958), and to hypothesize the finished structures of the creatures from the pieces he could find (Bowler, 1984), Cuvier became both the past master of the past and the foremost expert on life in the present.
Both Darwin and Wallace, co-inventors of the theory of natural selection, were similarly influenced by the ideas of Charles Lyell (1797-1875), Thomas Robert Malthus (1766-1834), and Robert Chambers(---). At issue were three concepts, respectively: 1) applying the principles of the present to the past on a gradual basis though a vast scale of time 2) systems producing more individuals in number than could survive to procreate 3) evolution unfolding across a multi-disciplinary scale effecting geological processes and life formation and transformation.
Charles Lyell published Principles of Geology in 1830 (Eiseley, 1958). In this, and in his second volume, a number of issues were presented which made immanent sense to naturalists such as Charles Darwin, groping for a synthesis of the many ideas circulating at that time.
Though Lyell did not believe in a linear arrow of time preceding from a specific moment in the past through the present into the future (Gould, 1987), he surmised a scale of time vast enough to accommodate theories of species transformation hitherto impossible to conceive. Lyell extrapolated processes such as wave erosion and rain damage into the past as processes naturally occurring over a long period without a major destruction or world destroying cataclysmic event (Haeckel, 1897). This viewpoint was in sharp contrast to cataclysmic theories such as Cuvier's.
At the same time, Lyell believed that the environment influenced species formation and extinction (Boorstin, 1983). He did not, at first, believe that this necessarily implied species evolution. After Darwin's publication of the Origin of Species, Lyell showed signs of changing his position to concur with Darwin. It was Lyell who coined the phrase, 'struggle for existence' (Eiseley, 1958).
If Lyell tilled the ground that prepared Charles Darwin for the concepts to follow, Thomas Malthus planted the seed that made evident to Darwin that something special had occurred (Boorstin, 1983: Richards, 1992). In 1838, after his five year voyage on the Beagle, Darwin read Malthus's, An Essay on the Principle of Population published in 1798. Darwin viewed in Malthus's work the engine behind the operation of his theory of natural selection. If more of any species is generated than can possibly survive, only the survivors will be adapted for that environment. If Darwin experienced a single moment when the theory jumped up and hugged him, this was it, in September or October of 1838. Twenty years later,Wallace would experience the same insight while recalling the same author read twelve years before. Both Darwin and Wallace were intimate with Lyell's and Malthus's work. From a similar context both men pieced together a similar scenario.
Darwin was a voracious reader. He fed his intuition from many sources. Adam Smith's (1776), Wealth of Nations, has been suggested to be an important foundation source for Darwin. As a follower of Lyell's, Darwin was familiar with the theorists Lyell respected, such as Lamarck. And, of course, Darwin's own grandfather, Erasmus Darwin, introduced the idea of the inheritance of acquired characters to the British lay and professional audience.
By 1844 Charles Darwin had established some clarity as to the dynamics of his theory of natural selection. This was the year that Robert Chambers, a book publisher, anonymously published Vestiges of the Natural History of Creation. With no selective process specified, Chambers offered a series of parallel evolutions from multiple appearances of life, as an explanation for the unfolding of life on earth. Chambers suggested this occurred over a Lyell-like non cataclysmic vast scale of time within a Lamarckian linear evolutionary path. The book was a popular success, evolution had now become a reasonable conjecture, but the book was critically panned by the academic community. This was not lost on Darwin. The few colleagues that Darwin had approached were not enthusiastic about his theory. Approximately 20 years would lapse between Darwin's creation of the theory of natural selection and its appearance as a paper in 1858.