Integrationism

How Evolution Evolves

“It is not the strongest of the species that survives, nor the most intelligent.  It is the one most adaptable to change.”
– Pseudo-Darwin

When Charles Darwin was conducting his researches during the Beagle voyage and upon returning home and settling in the picturesque village of Downe, England south of London, the broadest and deepest questions overarching and underlying the scientific inquiry of his age were ones of provenance.  The desire animating works from Linnaeus’s taxonomic classification of the biological world into hierarchies of species and genera (not coincidentally, it turned out, resembling a vast family tree encompassing all of creation) to Lyell’s incrementalist geology that helped push back the hypothesized age of the Earth (from thousands of years to millions, and eventually billions), upon both of which Darwin would heavily draw, was to illuminate where we are by understanding where we came from.  The science of the nineteenth century was essentially backward-looking.

These developments sparked a sort of crisis of belief, what Thomas Kuhn would later call a paradigm shift, as those with more traditional worldviews but also an awareness of the growing body of scientific knowledge, such as Darwin’s friend the Harvard botanist Asa Gray, attempted to reconcile them—for example by accepting the accumulating evidence supporting Darwin’s theory of biological evolution by means of natural selection but insisting that there was some higher purpose behind it and directing it, that these were the means by which God brought about His Creation.  The Linnean taxonomy resembled not only, after all, a family tree, but also in broad outline the traditional Great Chain of Being, with lowlier forms of life at the bottom and Man on top (and the angels and God of course above the natural realm, and governing its progress).  Evolution, it seemed, was a real phenomenon, but it had a direction, and a purpose: it was all leading to us—for the greater glory of God, of course.

As the nineteenth century progressed into the twentieth, however, the closer scientists looked at evolutionary processes, the less purpose they were able to see in them.  The development of living organisms over the geologic ages began to resemble less the Great Chain of Being, or even a family tree with a clear hierarchy and sense of direction visible among the growth of its trunks and branches, and more a densely-packed bush with twigs branching in practically every direction seemingly at random to fill every available environmental niche.  Not only was there no single direction of evolutionary progress, there was no direction or purpose to it at all—or rather, it seemingly moved in practically every direction at once, which amounted to the same thing, with no higher-order patterns clearly emerging from its random, drunkard’s walk.  The lesson of twentieth-century advances in specialized biology seemed to be that we are simply an accident, the meaningless, purposeless product of billions of chance genetic mutations and recombinations—that there is no direction to evolutionary processes and no real meaning to our existence.

As we move into the 21st century, many evolutionary theorists have begun to question this dogma.  Evolution does have an overall direction, they believe—though typically stated as some vague movement toward greater complexity or order, without much elaboration on how or why this should occur, or even what exactly that means.  This is the purpose of the present book.

I propose that evolution does have a direction, that evolutionary progress does exist—or to be precise, that it has two directions, one emerging from the other and then interacting with it, competing and collaborating with it, to give rise to definite patterns in long-term evolutionary trends.  My basic thesis is that at the most fundamental level evolution moves toward increased differentiation or specialization, becoming more narrowly adapted to a particular environmental niche—but a higher-order process emerges out of this creating a second evolutionary direction toward greater integration or generalization, synthesizing a broader range of functions and enabling a population of organisms to become more adaptable to a broader range of niches.  Call these two distinct directional evolutionary processes “involution” and “exvolution”, respectively.  And over longer time scales, these two processes themselves compete with each other in a higher-order level of selection, and the integrative, exvolutionary processes generally win out (the history of life is full of examples of this), so a pattern emerges that can be clearly defined at a qualitative level and perhaps even quantified.

Take human beings, for instance. We have evolved to adapt. We are the most general-purpose, and thus most adaptable, species that has ever existed on this planet. The range of environments to which human beings have been able to adapt themselves is truly awe-inspiring, from the Antarctic to outer space. Just as our ancestors spread from the cradle of humanity in Africa to populate the entire globe some hundreds of thousands of years ago, and their (much earlier) ancestors left the cradle of life in the oceans to colonize land hundreds of millions of years ago, it is our destiny to extend our habitat from this cradle called Earth, to inhabit other worlds—and relative to evolutionary timescales, we will do it soon (on the order of hundreds of years, if not sooner). As it moves toward greater generality, evolution accelerates.

Of course, many evolutionary theorists from Darwin to today have recognized, at least implicitly (and occasionally explicitly), this distinction between being better adapted to a specific niche and more generally adaptable to a broader range of niches, and the greater long-term advantage in the latter over the former.  However, none that I am aware of have ever recognized the fundamentality of this fact as the basic organizing principle governing the overall directionality of evolutionary trends or applied it to developing a worked out theory of such.  That is the task which I am undertaking: to define exactly how, and why, evolution necessarily tends to progress in the long-term toward greater complexity and order, and to examine the implications of this in terms of the overall organization of the universe over time and for meaning and purpose in our lives. Darwin largely answered the big questions about where we came from and how we got here—I want to complete his work by answering questions about where we’re heading and how we’ll get there.