The most recent and refined version of the evolutionary worldview that was first presented in Evolutionís Arrow can be found in the 34 page document The Evolutionary Manifesto which is here
Chapter 18. Humanity V. Bacteria
A major reason why most evolutionary biologists think that evolution is not progressive is bacteria. Bacteria seem to be at least as successful as humanity in purely evolutionary terms. They have survived on this planet for over 3,500 million years, they are still surviving, and they seem certain of continued survival, at least in the easily foreseeable future. But against the criteria that humans use to judge each other, bacteria are not very impressive. They are not smart, good looking, rich, or good at basketball. And they are not conscious of either their external environment or of themselves. But the importance to us of these criteria does not justify their use to judge the evolutionary success of all organisms. The ultimate criterion for judging evolutionary success must be survival, and on this, bacteria are doing at least as well as humanity.
In fact, many more bacteria are alive on earth now than humans, with about 10 trillion inhabiting a single spoonful of high quality soil. A strong case can be made out that bacteria always have been the dominant form of life on this planet, in terms of both numbers and total mass. Stephen J Gould suggests that we are living in the age of bacteria, and that since life began on earth, it has always been the age of bacteria.
But will it always be the age of bacteria in the future? Will bacteria in their current form be flourishing on this planet and elsewhere in the universe in a million years? In a billion years? Will they be the dominant form of life in the solar system, in the galaxy, or in the universe? Or will they be overtaken by other forms of life that will make them insignificant in the future evolution of life in the universe? Is evolution up to now on this planet just the first metre of a 10-kilometre run? Will the forms of life that are winning the race now be overtaken long before the business end of the race?
The fact that many species of bacteria have survived largely unchanged for over 3,500 million years fails to prove that evolution as a whole is not progressive. As I argued in Chapter 2, evolution is fundamentally progressive if there are sequences of potential improvements in living processes that evolution can exploit. The fact that some living processes have not yet exploited the sequences does not mean that the sequences do not exist. It may be that potentials for improvement exist, but the evolutionary mechanisms that have operated until now have not been creative enough to find ways for bacteria to exploit the potentials. This possibility cannot be dismissed without proving that there are no such sequences of potential improvements.
Nevertheless, bacteria do present a considerable challenge to the case for evolutionary progress. It is impossible to argue convincingly that evolution is fundamentally directional and progressive without satisfactorily explaining the success of bacteria. Progressionists must show that the lack of progress in many species of bacteria is not a result of the absence of potentials for improvement. They must point to sequences of potential improvements that will eventually drive progressive evolution once evolution has discovered how to exploit the potentials. Progressionists must demonstrate that bacteria in their current form will eventually be overtaken by new forms of life that are better able to exploit the potentials.
We are now in a position to answer this challenge. Since Chapter 2, we have seen that the benefits of cooperation provide general potentials for on-going improvement that can drive progressive evolution. Whatever evolutionary challenges they face, living processes will be able to respond more effectively through cooperation. As we have seen, the potential benefits of cooperation can be exploited by the formation of managed organisations. The larger the scale of the cooperative organisation, and the higher its evolvability, the more of the benefits of cooperation it will be able to exploit in its pursuit of evolutionary success.
We have seen what sort of living processes are likely to achieve future evolutionary success, and they are not bacteria. Each individual bacterium is a managed cooperative organisation of molecular processes. But individuals of most species of bacteria do not cooperate with each other, or with other organisms. They are not members of large-scale, managed cooperative organisations. The inability of most bacteria to adapt collectively means that they cannot respond effectively to wider-scale events, and cannot have large-scale impacts on their environment. They cannot team up to manage matter, energy, or other living processes on the scale of a centimetre, let alone on the scale of a city, country, nation, planet, solar system or galaxy.
In the long term, bacteria are likely to participate successfully in future evolution only to the extent that they are incorporated into larger-scale cooperative organisations. A few species have already become members of cooperative organisations. Earlier we looked at an example. The mitochondria within the eukaryote cells that form our bodies are the descendants of ancient bacteria. Mitochondria contribute cooperatively to the effective functioning of our cells, and through this to the success of ourselves and our social organisations. They are critically important members of the teams of cells and of the teams of teams of cells that have built the pyramids, invented agriculture, dammed rivers, built cities, and developed genetic engineering and other technologies.
In turn, the mitochondria benefit by being members of organisations that have exploited the benefits of larger-scale cooperation to achieve evolutionary success. Mitochondria by themselves are not able to adapt successfully on the scale that we and our societies do. But as members of our bodies and our social organisations, they share in the benefits that flow from our greater adaptive capacity. Mitochondria are not very smart. They have no capacity for mental modelling. But as members of organisations managed by mental modelling, they evolve and adapt as if they used mental modelling to do so. The management of the organisation controls their adaptation and evolution. If we and our societies use our superior evolvability to pursue evolutionary objectives successfully, we take our mitochondria along with us. Mitochondria have been to the moon and back, and if human organisation ever colonises the galaxy, so to will mitochondria.
Other bacteria are already participating in small-scale cooperative organisations. For example, plants get their essential nitrogen through the cooperative activities of bacteria. Plants cannot use nitrogen directly from the atmosphere. But Rhizobium bacteria that live in bulbous growths on the roots of leguminous plants convert nitrogen from the atmosphere into a useable form. As a further example, some bacteria have formed close cooperative relationships with cattle and other grazing animals. These animals could not digest grass without the activities of the bacteria in their stomachs.
As we have seen, the next great step forward in the evolution of life on this planet will be the formation of a highly evolvable and cooperative planetary organisation. The bacteria that will be successful in evolutionary terms will be those that become part of this planetary organisation, and that continue their membership as the organisation expands over even wider scales of space and time. Mitochondria are likely to have a role in this organisation while ever it includes humans. But the descendants of other bacteria are also likely to be part of the planetary organisation, at least for a considerable period into the future. This is because bacteria will be critically important to the effective functioning of the planetary organisation, and are likely to be managed by the organisation to enhance their contribution to it. Humanity is currently highly dependent for its survival on the activities of bacteria. We depend for our food, water and oxygen on the effective functioning of the living systems of the planet, and bacteria have a critical role in the operation of these systems. By decomposing dead organic matter, they return to useable form the elements that are essential to lifeoxygen, nitrogen, phosphorous, sulphur and nitrogen. Increasingly these bacteria will be managed by humans to optimise their contribution to the success of our societies.
It is not only bacteria that will be incorporated into the planetary organisation in this way. All living processes on the planet that can contribute to the success and expansion of the planetary organisation are likely to be managed as part of the organisation. Of course, we humans already attempt to manage living organisms and living systems when this contributes to achieving our objectives. A typical farm is an organisation of many types of organisms that are managed and controlled by humans to produce food and other resources for our benefit. Farmers use fertilisers and other means to promote the growth of plants that are useful to humans, and eradicate those that are not. They selectively breed animals and crops that are better at satisfying human needs. And farmers take advantage of the ability of bacteria to decompose plant and animal matter to fertilise the soil, and organise their farming practices to promote these bacterial activities where it is advantageous.
Farmers also promote cooperative interactions between organisms where these enhance productivity. For example, dogs are bred and trained to round up sheep, bees and plants are managed in ways that promote fertilisation of plants by bees, and the pattern of cropping is designed to take advantage of the beneficial effects of some crops on others. Management of living systems by humans is not limited to the running of farms. Irrigation projects and pest management schemes are larger-scale attempts to manage living systems for our ends. And on a smaller scale we attempt to manage the bacteria in our bodies and in our local environment to prevent disease.
In many cases, our attempts to manage other living processes have had disastrous consequences. In part this has been because our economic and social systems have failed to ensure that individuals and corporations capture the harmful environmental effects on others of their actions. In part it is because we do not have the knowledge or skills to manage complex living systems successfully. As we improve our systems of governance and accumulate greater knowledge and skills, we should overcome these difficulties. We will be able to manage living processes as part of the planetary organisation so that they contribute to the successful pursuit of evolutionary objectives.
We will redesign the living systems on which we depend, making them more efficient and effective for our purposes. As in farm management, we will manage organisms by changing their genes as well as by controlling their reproduction, environment, and access to food and other resources. Genetic engineering will be used to produce new organisms that function more efficiently and are better able to contribute to the objectives of the planetary organisation. We will use our capacity for mental modelling to continually revise the genetic arrangements of organisms, producing improvements wherever possible. The superior evolvability of humans will be used to exploit potentials for improvement in bacteria and other organisms that the genetic evolutionary mechanism has failed to exploit because of its far more limited evolvability. Organisms that are members of the planetary organisation will be managed so that they adapt and evolve in pursuit of the evolutionary success of the organisation. They will evolve and adapt as if they had the superior evolvability of the organisation as a whole.
Bacteria and other organisms will be engineered so that they are better at cooperating together and are managed more easily by the planetary organisation. Where these organisational organisms face damaging competition from free-living organisms that contribute less to the planetary organisation, the organisation will promote the cooperators at the expense of the free-livers. The planetary organisation will determine which living processes continue in existence and flourish, and which will not. Increasingly, free-living bacteria will be out-competed by managed bacteria that benefit from cooperation, or will be suppressed by the planetary organisation itself. It is also likely that human technology will eventually engineer machines that are better than some organisms at undertaking particular functions for the planetary organisation. This might involve the production of teams of microscopic machines that are able to reproduce themselves. These machines might out-compete or directly suppress free-living, unmanaged organisms.
In all these ways, the emergence of a planetary organisation will fundamentally change the living processes on this planet. As the planetary organisation evolves, and as it gets better at managing the living and non-living resources of the planet in its pursuit of evolutionary objectives, there will be vast changes in the types of living processes that inhabit the planet, and in the way they are organised. The evolution of life on earth has often been represented as a growing, branching bush. But as the planetary organisation emerges, this metaphor will no longer be appropriate. Increasingly, the diversity of organisms that has been produced by the branching process will be managed and unified into a single, cooperative organisation of living processes. The branches and twigs of the bush will no longer develop with relative independence. The bush and its growth will be organised and managed into a coherent whole that serves evolutionary objectives.
It is worth emphasising here that this unification of the living processes of the planet into a single organisation will not impose uniformity on them. It will not mean uniformity any more than it did for the groups of cells that were managed to produce multicellular organisms. To the contrary, the formation of managed organisations paves the way for a massive increase in diversity by allowing specialisation and a complex division of labour to emerge. This is what has occurred within cells, within multicellular organisms, and within societies of organisms. In the same way, the planetary organisation will produce unity within difference. The formation of a planetary organisation will facilitate a huge increase in the variety and diversity of living processes, including in human behaviour, and will unify this diversity into a coherent whole.
As the planetary organisation expands into the solar system and the galaxy, it will take with it those living processes that will contribute to its future success. It will leave behind those that will not. Whether or not an organism is retained as part of the expanding organisation will have a critical impact on its future evolutionary significance. Any bacteria and other organisms that are not part of the expanding cooperative organisation will be left to live out the rest of their existence on earth. Cosmologists predict that the sun will eventually expand into a red giant, engulfing most of the planets. When the solar system ends, the organisms that are left behind will also perish, if they survive that long.
In contrast, organisms that remain part of the expanding cooperative organisation will share in any future evolutionary success achieved by the organisation as a whole. They will benefit from the improved evolvability of the expanded organisation, and from its improving ability to manage matter, energy, and life over wider and wider scales of space and time. When the organisation moves from a particular solar system that is soon to collapse, it will take the organisms with it. When it harnesses the energy of a number of stars to enable it to remodel an area of the galaxy to produce a better environment for its purposes, its member organisms will also benefit.
Gould was wrong when he stated that it will always be the age of bacteria. To know what sort of living processes will be successful in future evolution, it is essential to know where evolution is headed. You must know if there are potential improvements in existing living processes that will drive progressive evolution, and, if so, what these improvements are. You must know what the evolutionary game is, and what its winners will look like. We have seen that the evolutionary future will belong to cooperative organisations of living processes that continue to increase in scale and evolvability. If humans change in the right direction both as individuals and socially, we may play a significant role in this future evolution. But we can say with certainty that free-living, unorganised, unmanaged bacteria will not. Non-cooperative, unorganised bacteria have done well in terms of survival up to now. But this is only because it has taken evolution this long to produce an organism that is capable of managing large-scale cooperative organisations of bacteria and other organisms. The future belongs to cooperative organisations, and bacteria will share in this future only to the extent that they participate in and contribute to these organisations. The same applies to us.
. Ayala, F. J. (1997) Ascent by natural selection. Science 275: 495-6.
. Gould, S. J. (1994) The Evolution of Life on Earth. Scientific American October: 63- 69.
. A number of examples of cooperation between bacteria and other organisms are examined in Margulis, L. and D. Sagan (1986) Microcosmos. New York: Summit.
. See, for example, Clapham, W. B. (1973) Natural Ecosystems. New York: Macmillan.
. Stewart, J. E. (1997) Evolutionary Progress. Journal of Social and Evolutionary Systems 20: 335-362.
. See Drexler, K. E. (1986) Engines of creation: the coming era of nanotechnology. New York: Doubleday Anchor.
. Adams, F. and Laughlin, G. (1999) The Five Ages of the Universe. New York: Free Press.
. Stewart: Evolutionary Progress. op. cit.