Evolution is described by some as a non-directional process.
The path living systems take is described as being contingent upon local environmental conditions.
While it is true that the events that take place as a consequence of evolution depend critically on the environment in which they occur, the conclusion that the resulting process does not have a directional character neglects the possibility that there may be systemactic regularities in the environment which effectively provide such a direction.
In fact in the natural world the environment is full of regularities. The spatial and temporal structure of the universe is characterised by large scale structure and regularity. This means that systematic progress is still a possibility - despite the possibility of disasters and setbacks.
A brief examination of the history of life shows that it
is characterised by an accumulation of adaptive knowledge.
In particular, the biosphere is accumulating "know how" that
helps it more rapidly identify sources of potential energy -
and degrade them in the process of constructing offspring.
The accumulation is progressive, cumulative - and inexorable
in character - and the resulting ratchet mechanism provides
evolution with a powerful directional character.
The Great Chain of Being
Of course, the sense of an evolutionary direction in living systems has been recognised for a long time.
Some buddist scholars partition living systems into heaven, humans, fighting spirits, animals, ghosts and hell - on a kind of karmic ladder of rebirth.
Medieval scholars visualised the natural order in terms of the degree of
perfection of organisms.
See the diagram of The Great Chain of Being on the right
hand side. This illustrates a ladder from dirt, up through plants and
animals, through people, on to angels and then up to god.
This picture sometimes gets criticised for failing to represent a
cladistic tree - but that rather misses the point of what the
picture is supposed to represent.
Though one can quibble about which organisms belong where, it turns
out that the picture is just about right - when it comes to looking
at evolution's directionality.
One thing it gets right is that it puts humans in a prominent
position. From the point of view of the development of technological
know-how, this is absoultely correct - it turns out that our own
species is of pivotal importance.
Other thinkers have visualised much the same idea in other ways - e.g. the:
Geosphere -> Biosphere -> Infosphere -> Noosphere -> Omega point
...terminology - derived from the work of Teilhard de Chardin.
More recently, life's directional character has been recognised by:
Technological setbacks are possible in principle. However the environment represented by the universe seems to be sufficiently life-friendly to mean that the probability of major setbacks is low.
Possible setbacks would include mass extinction events - perhaps caused by metorite impacts, seismic activity, sun storms, etc.
During such events whole classes of species may be obliterated - and their technology lost.
However much of life's most important technology has managed to survive such events. Often it has done so by finding its way into bacteria and single-celled organisms which can sometimes be relatively robust when it comes to mass-extinction events.
Certainly - in the history of life on this planet so far - the setbacks have been a relatively minor force in comparison with the progress that has been made - and many discoveries about "ways of making a living" have been successfully preserved for billions of years.
It appears that the universe is sufficiently benign towards living systems that they are able to flourish and expand within it.
Gould and Dawkins
Dawkins and Gould had opposite views on the issue of whether life
could be said to have a direction.
In a book on the subject, Gould claimed evolution lacked a progressive character - while Dawkins wrote in [a review of that book]:
Notwithstanding Gould's just scepticism over the tendency to label each era by its newest arrivals, there really is a good possibility that major innovations in embryological technique open up new vistas of evolutionary possibility and that these constitute genuinely progressive improvements (Dawkins 1989; Maynard Smith & Szathmary 1995). The origin of the chromosome, of the bounded cell, of organized meiosis, diploidy and sex, of the eucaryotic cell, of multicellularity, of gastrulation, of molluscan torsion, of segmentation - each of these may have constituted a watershed event in the history of life. Not just in the normal Darwinian sense of assisting individuals to survive and reproduce, but watershed in the sense of boosting evolution itself in ways that seem entitled to the label progressive. It may well be that after, say, the invention of multicellularity, or the invention of metamerism, evolution was never the same again. In this sense there may be a one-way ratchet of progressive innovation in evolution.
For this reason over the long term, and because of the cumulative character of coevolutionary arms races over the shorter term, Gould's attempt to reduce all progress to a trivial, baseball-style artefact constitutes a surprising impoverishment, an uncharacteristic slight, an unwonted demeaning of the richness of evolutionary processes.
The view given here is very similar to the one Dawkins expresses.
A drunkard's walk is a very poor and misleading metaphor for evolutionary progress. If you wanted to emphasise the random component of evolution, a far superior model is that of a gas expanding into a vacuum. However, such simple models are fundamentally impoverished: they miss out much of the interesting and important dynamics present in evolutionary processes. A much better model describes evolution as an optimisation process which seeks the fittest organisms and ecosystems.
The living explosion
Life looks a lot like a explosive process - where we
are witnessing the process shortly after ignition.
Currently most of the niches that will be occupied in the
future by large and complex organisms are all lying empty.
Living systems are expanding into these niches - very much
like a gas expanding into a vacuum.
As with most explosive events, there's a clear direction:
living systems are getting progressively better and better
at identifying sources of energy and dissipating them - in
the process of making copies of their genes.
Life is so much like an explosion that - while life still seems to have a single origin - our descendants will even be able to look back and see an identifiable epicenter, with life's signature spreading radially outwards from it.
The end of progress
Will living systems eventually lose their directional character - and reach a steady state?
Few explosions retain their explosive character indefinitely. Eventually, they exhaust their available resources and slow down, fade and die. It may well be that living systems will suffer the same fate.
However there's no sign that this is likely to happen any time soon - the living explosion shows every sign of continuing for many more billions of years - and building in intestity for a very long time to come.
When a system exhibits motion in a clearly-identifiable direction, it's human nature to look to see if it is heading towards something.
Some argue that - in the case of evolution, this is not
possible - since the mechanism of evolution works only on
the basis of past experience, and can neither see nor
predict the future.
However this is a feeble argument. All physics works on the
basis of past events causing future ones - but that does not
mean that systems which predict the future can't exist.
There are plenty of examples of prediction in
nature. Weather forecasters regularly predict the future -
despite the fact they all their knowledge stems from past
Since weather forecasters are part of nature, it seems
clear that nature contains elements capable of predicting
Organisms can not only predict the future, they can influence
it. They have plans and goals. The evolutionary process consists
of a number of such individuals - and it effectively inherits
the goals of the individuals that compose it.
So - the question can legitimately be asked - what is
evolution's "goal" - what is it heading towards?
The answer seems to be fairly clear - life is trying to
occupy all space, and to become master of the universe.
More recently, Gould's idea of undirectional evolution seems to have become more popular. Many point to the unilinear progress theories that inspired the historical social Darwinism movement - and claim the evolution is a bush - not a ladder.
I think Gould's promotion of the idea of evolutionary directionlessness is probably down to his Marxist leanings. If evolution is non-progressive that makes everyone equally "advanced" - an appealing politically-correct notion. A similar motivation was apparently behind Gould's farcical book about intelligence testing.
This kind of thinking led Gould to reject the links between cultural evolution and organic evolution - since they so evidently make a mockery of his whole idea.
Progress in organic and cultural evolution is much too obvious to deny. In fact, not even Gould managed to deny it entirely - though he clearly tried.
Progress denialism is scientific nonsense. Evolution can be accurately viewed as a giant optimisation process, set up to maximise entropy. As such it is incredibly directional. It is very strange to hear people denying evolutionary progress in modern times, when it is staring us so clearly in the face. To give an example of what modern progress denialism sounds like, here is
Progress is really a subjective term. I don't believe, except in some pretty trivial cases, I don't believe in an objective "progress" - there's only difference. I think one of the most misleading things that people who claim to be rational do to themselves is draw that chart of evolution that starts with a kind of squirrel and ends with a human and works its way through a kind-of smooth upward curve of people emerging from monkeys and apes and earlier slope-shouldered hominids all the way up to erect-walking man as though... it's a kind-of very anthropocentric way of thinking about our evolutionary course as though we were being perfected - instead of merely adapting to a set of circumstances that themselves were changing from time-to-time. I think that there's lots of reasons to believe that instead of the anthroposcene, we are living in the very late bacterioscene. You know, the era that started when single-celled organisms created the atmosphere and that everything else is really in the service of those single-celled organisms especially since 100X more cells in your body belong to single celled organisms than to your human genome so we are arguably just a kind-of vehicle for moving bacteria around and the fact that we are walking on two legs and keeping our shoulders back when we go is in large part irrelevant to the course of those bacteria - so I don't really believe in progress as much as I believe in change.
This sort of thing is nonsense. It is just a matter of fact that evolution has resulted in enormous progress over the last four billion years. I think scientists should unite in pointing out what ridiculous nonsense progress denialism really is.
What Technology Wants by Kevin Kelly (2010) Verbalizing visceral feelings about technology, whether attraction or repulsion, Kelly explores the 'technium,' his term for the globalized, interconnected stage of technological development. Arguing that the processes creating the technium are akin to those of biological evolution, Kelly devotes the opening sections of his exposition to that analogy, maintaining that the technium exhibits a similar tendency toward self-organizing complexity. Having defined the technium, Kelly addresses its discontents, as expressed by the Unabomber (although Kelly admits to trepidation in taking seriously the antitechnology screeds of a murderer) and then as lived by the allegedly technophobic Amish. From his observations and discussions with some Amish people, Kelly extracts some precepts of their attitudes toward gadgets, suggesting folk in the secular world can benefit from the Amish approach of treating tools as servants of self and society rather than as out-of-control masters. Exploring ramifications of technology on human welfare and achievement, Kelly arrives at an optimistic outlook that will interest many, coming, as it does, from the former editor of Wired magazine. View on Google Books the book page, the author page, or the book contents.
Evolution's Arrow: the direction of evolution and the future of humanity by John Stewart (2000) Evolution's Arrow argues that evolution is directional and progressive, and that this has major consequences for humanity. Without resort to teleology, the book demonstrates that evolution moves in the direction of producing cooperative organisations of greater scale and evolvability - evolution has organised molecular processes into cells, cells into organisms, and organisms into societies. The book founds this position on a new theory of the evolution of cooperation. It shows that self-interest at the level of the genes does not prevent cooperation from increasing as evolution unfolds. Evolution progresses by discovering ways to build cooperative organisations out of self-interested individuals. The book also shows that evolution itself has evolved. Evolution has progressively improved the ability of evolutionary mechanisms to discover effective adaptations. And it has produced new and better mechanisms. Evolution's Arrow uses this understanding of the direction of evolution to identify the next great steps in the evolution of life on earth - the steps that humanity must take if we are to continue to be successful in evolutionary terms. A key step for humanity is to increase the scale and evolvability of our societies, eventually forming a unified and cooperative society on the scale of the planet. We must also transform ourselves psychologically to become self-evolving organisms - organisms that are able to escape their biological and cultural past by adapting in whatever directions are necessary to achieve future evolutionary success. Author web site. View on Google Books the book page, the author page, or the book contents.
The Phenomenon of Man by Pierre Teilhard De Chardin (2010) Visionary theologian and evolutionary theorist Pierre Teilhard de Chardin applied his whole life, his tremendous intellect, and his great spiritual faith to building a philosophy that would reconcile religion with the scientific theory of evolution. In this timeless book, which contains the quintessence of his thought, Teilhard argues that just as living organisms sprung from inorganic matter and evolved into ever more complex thinking beings, humans are evolving toward an "omega point"—defined by Teilhard as a convergence with the Divine. View on Google Books the book page, the author page, or the book contents.
The Evolution of Darwinism: Selection, Adaptation and Progress in Evolutionary Biology by Timothy Shanahan (2004) No other scientific theory has had as great an impact on our understanding of the world as Darwin's theory outlined in his Origin of Species. Yet the theory has been the subject of controversy from its very beginning. This book focuses on three issues of debate in Darwin's theory of evolution--the nature of selection, the nature and scope of adaptation, and the question of evolutionary progress. It traces the varying interpretations to which these issues were subjected historically through the fierce contemporary debates continuing to rage. View on Google Books the book page, the author page, or the book contents.
The synergism hypothesis: A theory of progressive evolution by Peter Corning (1983) This book represents a major theoretical synthesis between the life sciences and the social sciences. Peter Corning shows that the selective advantages arising from various kinds of cooperation-from single-celled creatures to wolf packs to modern nation-states-are the cause of the directional aspect of evolutionary history, that is, the progressive emergence of more complex, hierarchically organized systems in the biological, cultural, and political realms. View on Google Books the book page, the author page, or the book contents.
Nature's Magic: Synergy in Evolution and the Fate of Humankind by Peter Corning (2003) In Nature's Magic Peter Corning states that synergy--a vaguely familiar term to many of us--has been a wellspring of creativity in the natural world and has played a key role in the evolution of cooperation and complexity at all levels, from physics and chemistry to the latest human technologies. The 'Synergism Hypothesis' asserts that synergy is more than a class of interesting and ubiquitous effects. It has also been a major causal agency in evolution; it represents a unifying explanation for biological complexity and represents a different perspective on the evolutionary process. In contrast to gene-centered theories, or postulates of self-organization and emergent 'laws' of complexity, the Synergism Hypothesis represents, in essence, an 'economic' (or bio-economic) theory of complexity. View on Google Books the book page, the author page, or the book contents.
Holistic Darwinism: Synergy, Cybernetics, and the Bioeconomics of Evolution by Peter Corning (2005) In recent years, evolutionary theorists have come to recognize that the reductionist, individualist, gene-centered approach to evolution cannot sufficiently account for the emergence of complex biological systems over time. Peter A. Corning has been at the forefront of a new generation of complexity theorists who have been working to reshape the foundations of evolutionary theory. Well known for his Synergism Hypothesis—a theory of complexity in evolution that assigns a key causal role to various forms of functional synergy—Corning puts this theory into a much broader framework in Holistic Darwinism, addressing many of the issues and concepts associated with the evolution of complex systems. Corning's paradigm embraces and integrates many related theoretical developments of recent years, from multilevel selection theory to niche construction theory, gene-culture coevolution theory, and theories of self-organization. Offering new approaches to thermodynamics, information theory, and economic analysis, Corning suggests how all of these domains can be brought firmly within what he characterizes as a post–neo-Darwinian evolutionary synthesis. View on Google Books the book page, the author page, or the book contents.
The Rational Optimist: How Prosperity Evolves by Matt Ridley (2011) For two hundred years the pessimists have dominated public discourse, insisting that things will soon be getting much worse. But in fact, life is getting better—and at an accelerating rate. Food availability, income, and life span are up; disease, child mortality, and violence are down all across the globe. Africa is following Asia out of poverty; the Internet, the mobile phone, and container shipping are enriching people's lives as never before. In his bold and bracing exploration into how human culture evolves positively through exchange and specialization, bestselling author Matt Ridley does more than describe how things are getting better. He explains why. An astute, refreshing, and revelatory work that covers the entire sweep of human history—from the Stone Age to the Internet—The Rational Optimist will change your way of thinking about the world for the better. View on Google Books the book page, the author page, or the book contents.
Nonzero: The Logic of Human Destiny by Robert Wright (2000) Evolution meets game theory in this upbeat follow-up to Wright's much-praised The Moral Animal. Arguing against intellectual heavyweights such as Isaiah Berlin, Karl Popper and Franz Boas, Wright contends optimistically that history progresses in a predictable direction and points toward a certain end: a world of increasing human cooperation where greed and hatred have outlived their usefulness. This thesis is elaborated by way of something Wright calls 'non-zero-sumness', which in game theory means a kind of win-win situation. The non-zero-sum dynamic, Wright says, is the driving force that has shaped history from the very beginnings of life, giving rise to increasing social complexity, technological innovation and, eventually, the Internet. From Polynesian chiefdoms and North America's Shoshone culture to the depths of the Mongol Empire, Wright plunders world history for evidence to show that the so-called Information Age is simply part of a long-term trend. Globalization, he points out, has been around since Assyrian traders opened for business in the second millennium B.C. View on Google Books the book page, the author page, or the book contents.
Monad to Man: The Concept of Progress in Evolutionary Biology by Michael Ruse (2009) The idea of evolution: it fascinates some of us, disturbs others, and leaves only a very few people indifferent. In a major new interpretation of evolutionary theory, Michael Ruse pinpoints the common source of this attraction and discomfort. A renowned writer on evolutionary theory and its history, Ruse has long been sensitive to the fact that many people - and not simply religious enthusiasts - find something deeply troubling about much of what passes for science in evolutionary circles. What causes this tension, he finds in his search of evolutionism's 250-year history, is the intimate relationship between evolution and the secular ideology of progress. Ubiquitous in Darwin's time, the idea of an unceasing improvement in life insinuated its way into evolutionary theory from the first. In interviews with today's major figures in evolutionary biology - including Stephen Jay Gould, Edward O. Wilson, Ernst Mayr, and John Maynard Smith - and in an intimate look at the discoveries and advances in the history and philosophy of science, Ruse finds this belief just as prevalent today - however it might be denied or obscured. His book traces the delicate line between those who argue that science is and must be objective and those who deem science a "social construction" in the fashion of religion or the rest of culture. It offers an unparalleled account of evolutionary theory, from popular books to museums to the most complex theorizing, at a time when its status as science is under greater scrutiny than ever before. View on Google Books the book page, the author page, or the book contents.
The Evolution of God by Robert Wright (2010) Straddling popular science, ancient history, and theology, this ambitious work sets out to resolve not only the clash of civilizations between the Judeo-Christian West and the Muslim world but also the clash between science and religion. Tracking the continual transformation of faith from the Stone Age to the Information Age, Wright, a self-described materialist, best known for his work on evolutionary psychology, free trade, and game theory, postulates that religious world views are becoming more open, compassionate, and synthesized. Occasionally, his prescriptions can seem obvious—for instance, that members of the different Abrahamic faiths should think of their religions as “having been involved, all along, in the same undertaking.” But his core argument, that religion is getting “better” with each passing aeon, is enthralling. View on Google Books the book page, the author page, or the book contents.
The Better Angels of Our Nature: Why Violence Has Declined by Steven Pinker (2011) Faced with the ceaseless stream of news about war, crime, and terrorism, one could easily think we live in the most violent age ever seen. Yet as New York Times bestselling author Steven Pinker shows in this startling and engaging new work, just the opposite is true: violence has been diminishing for millennia and we may be living in the most peaceful time in our species's existence. For most of history, war, slavery, infanticide, child abuse, assassinations, pogroms, gruesome punishments, deadly quarrels, and genocide were ordinary features of life. But today, Pinker shows (with the help of more than a hundred graphs and maps) all these forms of violence have dwindled and are widely condemned. How has this happened? View on Google Books the book page, the author page, or the book contents.