Pareto optimality and brain-evolution in Late Pleistocene Hominins

paretoA guest opinion by R. Chandrasoma, that understanding the world and adapting to it are not quite the same

It seems right and proper to suppose that the whole is maximally good if each of its parts is fashioned to be the best in its own right. Much of biological thinking on matters of evolution and adaptation is underwritten by this assumption. Thus, the wing of a bird must be aerodynamically the ‘fittest’ if the bird as a whole excels as a survival machine. If we treat the living body as a system of interrelated agencies each with its own foibles and limitations is it not an error to suppose that what is best for each part is necessarily the best for the whole?

In this connection the notion of a Pareto Improvement (much discussed in the social sciences) is very illuminating. Given an initial allocation of goods among a set of individuals, a change to a different allocation that makes at least one individual better off without making any other individual worse off is called a Pareto improvement. An allocation is defined as Pareto efficient or Pareto optimal when no further Pareto improvements can be made. This thinking can be directly extended to engineering gystems and it is this extension that impacts directly on our concepts related to the evolution of biological complexity. Suppose that an engineering system is Pareto efficient – this does not mean that parts cannot be improved – it means that the parts hang together in such an integrated fashion that any improvement in a part in a Pareto-efficient machine imperils the whole in terms of overall efficiency or goodness.

Before we discus our hypothesis about Brain-Evolution in the late Pleistocene and the seeming ‘Pareto compulsion’ in the dynamics of change in that challenging age, it is useful state some generalizations framing the classical understanding of the mechanisms of organic evolution. This classical theory – that which is understandably called Darwinian Evolution – is based on the genetic dynamics of parts. The evolutionary challenge takes the form of a question ‘is this part in its mutant form better in the struggle for life in a specified environment? While not contesting the usefulness of this explanatory paradigm in our understanding the history of life, it appears that significant aspects of organic evolution are ignored or misinterpreted if it is too rigidly relied on. As an example of such limited thinking is the conventional analysis of mutational advantage in a given species – the question asked standardly is ‘ does it (the mutation) confer benefits in terms of survival and reproductive advantage to its bearer? While this is, undoubtedly, an impotant facet of investigation, it appears that two highly relevant issues are buried or obfuscated by those who fancy a doctrinaire approach in such matters. (An approach sometimes pilloried as Darwinian Fundamentalism.)

The first troublesome issue – mostly ignored in traditional Darwinian explanations – is that organic evolution is not an ‘open’ process of the kind fancied by diehard exponents of a ‘pure’ or ‘classical’ Darwinism. This purist line of thinking is epitomized in “Dawkin’s Law’’ expounded by the renowned author Richard Dawkins. According to this ‘Law’ reproducing entities, simple hereditary processes and mutation in a punishing environment are all that are required to ignite a process that leads to the wondrous complexity of organic life we see in such places as Planet Earth. Does not this astonishingly lean approach to organic evolution miss something very important – that the process-dynamics of material systems have an ‘intelligence’ of their own that sharply limits morphogenesis? Organic ‘complexification’ of the kind seen in the history of life on our Planet has a stamp that strongly reflects an inner morpho-dynamic of material systems – unrelated to the Darwinian logistic – that is barely understood today. The prescient biologist JBS Haldane asked a very pertinent question – why are there more species of beetle – by far – than of any other Metazoan group? (With the Nematode worms not far behind in this number game.) The answer to this question must go beyond Darwinism since it is rooted in an understanding of the eigentransforms of epigenetic systems that current science has barely touched on. The early naturalists were struck by the persistence of organic archetypes and saw the hand of the Creator in the strange regularities in morphogenesis. We will not pursue this matter further except to note that organic forms are often exuberantly beautiful – surely a paradoxical feature for those accustomed to mean and lean explanations of the doings of nature. Beauty cannot be ‘reached’ by the accumulation of beautiful parts.

We examine next a lesser problem in many ways – but pivotal so far as our own evolution is concerned. A pareto-efficient system – as explained in our opening paragraphs – is such that parts cannot be modified without ‘degrading’ tha whole. Why are animal archetypes so resistant to change? Consider a Frog – its bizarre design has persisted for millions of years – so have the crazily constructed Tortoises and Turtles. In understanding such morphological paradoxes it is surely silly to spin yarns about a history of selective shaping and a morphological excellence that defies all winds of subsequent change. The truth is that both frogs and turtles (like the the beetles referred to above) are primarily expressions of an ontogenetic intelligence that is ‘quantized’ – that is, driven by ill-understood morphie forces to produce archetypes. Why are prawn-like forms so abundant in nature – that which naturalists call the caridioid facies? Is it because the prawn-like form is a marvelous match to conditions of life in oceans, rivers and puddles? The answer is the same as with the Beetles – what we see is the expression of an eigentransform of organic nature that battles with the world (the struggle for life in the Spencerian sense) to survive and reproduce.

Allow us to hypothesize further on these lines. The ‘natural archetypes’ are largely pareto–efficient because of inner morphic constraints about which we know very little. This means that evolution is largely about the mysterious appearance of archetypes and their subsequent ‘fine-tuning’. It is naïve error – albeit widespread in the community of the learned – that archetypes are the result of the ‘stitching together’ of ‘useful’ mutants. The ‘explosive’ appearance of Metazoan complexity at the very dawn of multicellular life is a great conundrum to evolutionary gradualists of the classical school of Darwinism if this ‘accretion’ theory is supposed to be correct. Since such remote events (the Cambrain drama) cannot be unambiguously assessed for meaning and significance, let us deal with events closer home – the evolution of monkeys and apes in the Miocene and later ages.

Let us – first – ask a question. Is the Simian facies (monkey-like body-form) an evolved adaptation of a generalized kind engineered by stitching together over time of individually useful mutations? If this, indeed, is the case, why has this Simian facies appeared independently in the Old World and the New? Why is the New World Horse (now extinct) a near exact copy of its unrelated Old-World counterpart? Why is the Marsupial Mole so close to true mole in overall morphology ? To the ‘classicist’ in such evolutionary matters there is no enigma – the environment shapes its counterpart organic form and where environments are similar and their niche-structure parallel, the forms evolved will ‘converge’ to a morphic type dictated by the ‘opportunity-structure’ of the environment.

This is a kind of Zoological Platonism in which forms of life exist before their evolutionary realization and are expressed materially through mutation and selection. Having digested these generalities, let us turn to the natural history of Man to see things against a background constituted by what we have said above on Archetypes, Pareto-efficiency and Zoological Platonism. These ideas are, arguably, a foundation for a new approach to the understanding of our history as an organic species – an evolutionary saga that mixes tha classical Darwinian ‘plodding’ with extraordinary turns of events that makes us what we are today. It is reasonable to suppose – in the light of what we have said earlier – that the simian facies (Monkey-like form) is not an evolved adaptation in the sense that its overall design was not piece-wise engineered by the smart choice of chance mutants in forms struggling to survive.

Evolution – here we refer to the grand sweep of this awesome transformation of life – proceeds through developmental innovations that arise by an unsettling of ontogenesis in survival machines pressed to the limit. Instability – the precariousness of the fine balance of metabolic agencies in the germ – results in a sudden and novel program of organic unfolding leading to new ‘appearances’ that are subject to the stern test of survivability across time. Thus the simian facies is a proffering – a deus ex machina – of a primed developmental system as a possible answer to the great challenges encountered in that day and age. Monkey–like vertebrate forms appeared across the world not in answer to a specific environmental opportunity but because ontogenetic systems in the vertebrate category were everywhere primed for such a shift. The environmental challenge provided by trees and forests concretized a potential that had little to do with point mutations and Darwinian selection. Thus monkey-like forms appeared in near synchrony in the tropical and subtropical parts of the world as if ‘The Maker’ had suddenly (and lately) favoured the Monkey form just as he had a great fancy for Beetles in an earlier age.

If some critic finds this explanation fanciful, let them recall the paleontological history of the early mammals for which the osteological evidence is plentiful. At least a dozen independent lines of Synapsid evolution moved relentlessly in the direction of mammalian organization. This is most astonishing because mammalian features were not selected for but educed independently in parallel in the history of this group. The relevance of this extraordinary history to our musings about archetypes and Simian evolution is very clear. Let us return to our primate ancestors. We said the advent of the simian facies is a unique and historic ‘presentation’ in the unfolding of what can be called the ‘potential of the germ’ – not to be confused with the ‘potential of the gene’ through variation and selection. The latter is in a true sense a peripheral affair incapable of creating archetypes. The hominin facies – if we are permitted to use this neologism – is a sub-archetype within the larger schema (the simian facies) and appeared repeatedly in diverse parts of the world by the kind of parallel evolutionary eduction that some of the synapsid mammals grandly displayed at an earlier age

Let us throw further light on the murkier issues. In consonance with the thinking adumbrated earlier, the hominin archetype refers to a simian form that is erect, freely bipedal, large-brained with emancipated forelimbs and hands capable of more than simple grasping. Speech and social consciousness reach a pitch that sets this group apart from all other living organisms. We are speaking of men and women, new and old. There is an entrenched belief that the earlier ‘men’ were truly ‘archaic’ in that they lacked brain-power and the finer feelings that led to the fantastic artifacts and ‘mentifacts’ that characterize our age. This is a popular but totally false picture of human evolution. If we are to speak of the perfection of the hominin archetype – not to be confused with artifact-wizardry and high living – this was achieved in the late Pleistocene by such splendid Hominin forms as Neanderthal Man and the Cro-Magnon Man. These large and impressive hominins had heftier bodies and much greater brains that any contemporary human type. (The brains of these ‘ancients’ were around 300 cc larger than their counterparts found in hominin variants living today and their bodies robust to a degree unheard of in modern populations of Homo sapiens.)

It must be remarked at this point that most living human types represent a regress from an earlier state of ‘exuberance’ in the overall moephology. This is true for most mammals and birds that had a megafaunal phase prior to the latest glaciation of our Planet. All this may soud heretical – indeed unbelieveable – given that we live in an age where the current version of Homo sapiens rules the world in a way that no prior version of this species could dream of matching. Are not the earlier forms mere savages in comparison with the masters of technology that have the very planet they inhabit in thrall? It is here that the notion of pareto optimality plays a decisive and illuminating role. Note first that great brains were formed – evolved in the hominin line – long before civilization and the mastery of the environment that characterizes our species became an expressed reality. Indeed, this ‘civilizing wave’ reached ‘early humans’ very late in the day and its ‘torchbearers’ were Semitic nondescripts of the Afro-European region that were far inferior to the pioneer Cro-Magnons and Neanderthals in brain-power and physique. This is the great paradox.

It is the universally held belief that great brains in beautiful bodies were sine qua non for thre rise of the kind of civilization that we celebrate as our hallmark. The reality is that brute ‘brain-power’ may have obstructed such processes as social action through division of labour – the instinctive capacity to serve so called ‘leaders’ in hierarchical social structures. The unassailable truth is that ordinary people led beastly lives of servitude to leaders in so-called civilized societies right up to modern times. For most, then, high reflective intelligence is a maladaptation and the extra-large brain he carries in his head is not all unalloyed goodness.

As as aside, let us note that in the Late Pleistocene a wondrous Megafauna developed across the World that encompassed mammalian species ranging from the Imperial Elephant to such ‘oddities’ asGiant Lemurs in Madagascar. (We shall not speak about the Giant Birds of this period.) The are twin mysteries wrapped in this megafaunal ‘explosion’ that surely bear on the episodes of late anthropogenesis we are discussing. Why did animals far superior in size and majesty come to be replaced by lesser forms? Why was the Imperial Elephant (a species of Elephas) ‘succeeded’ by the a clear inferior – the Indian Elephant? Why did great forms die out while inferiors carried on? Let us recall the principle of pareto-efficiency. A system can be improved significantly in parts and aspects while diminishing in long term survivability . Without more ado leat us try to answer that question wrapped in enigma – Why did very large-brained and superior hominins (exemplified by such types as the Neanderthal Man and the Cro-Magnon Man) suffer the ‘indignity’ of being replaced by lesser human kinds? The question ‘Why did the Imperial Elephant face doom while its lesser brother survive?’ enraps a parallel evolutionary enigma. An organism that is seemingly better in the ‘engineering sense’ can be defeated by a lesser competitor because the latter has the advantage in pareto-efficiency – the greater clout or goodness of the competitor in parts being more than offset by a decline in overall survivability. It is useful to pursue this argument with the aforementioned paradox of the lesser gaining on the greater in mind. Let us call the large-bodied and large-brained hominins of the past (Cro-Magnon, Neanderthal etc.) as Apex Humans. The great question is then best phrased as follows – why were these physically better men and women replaced by their clear inferiors in brain and body? This situation is by no means unique – as we had occasion to point out earlier.

The existent mammalian fauna is a poor version of a grandeur that prevailed before the recent Ice Ages. Large brains – or very large brains – may be ‘dysgenic’ in that too much cogitation – or deep reflection – may lower fertility while boosting meditative states that diminish social cohesiveness and the ‘sex drive’. It is no surprise, then, that men with smaller-bodies and less acute brains outpaced and, finally, exterminated their clear superiors in size and intelligence. There are many kinds of humans on Planet Earth in this day and age – which kind will be found a thousand years hence? Surely not the largest, the cleverest and the most beautiful? A great ‘superstition’ must be debunked here – that the greater the brain-power or intelligence, the greater the chance of adjustment and survival in a challenging world. It is this myth that makes us suppose that longe-lived aliens in other worlds will be far superior us in science and technology. The ill-fated SETI program foundered on this erroneous supposition. As Prof. John D Barrow has pointed out in his recent books, superlative feats of science and technology can recoil malevolently on its inventors and, far from helping mankind,  could be the cause of its premature demise.

That this dismal scenario is not fantasy is clear to unbiased observers of the world we currently live in – where unrest and a deepening social malaise seem to be the fruit of too much cleverness on the part of our over-dominant species – Homo sapiens. Understanding the world and adapting to it are not quite the same.

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