Does Evolution Have a Direction?

Two people in the last month have questioned me about my belief in a direction to evolution. One referred to a book that stressed that evolution was random. The other referred to writings of Steven Jay Gould about people’s desire for wanting to find direction in history and evolution but that there was no such direction. I do believe there is a direction to evolution (shaped by the Second Law of Thermodynamics). This sense of direction lies at the heart of HOPE’s mission: to turn the prow…back upstream. And yet I can also agree with people who say that evolution is random at its basic level. So I will use this issue of Cairns to practice articulating the way I resolve this paradox.

The key is “emergent behavior” at different levels . (The following quote from page 86 of Complexity describes “emergent behavior”. “Every topic of interest had at its heart a system composed of many, many “agents”. These agents might be molecules or neurons or species or consumers or even corporations. But whatever their nature, the agents were constantly organizing and reorganizing themselves into larger structures through the clash of mutual accommodation and mutual rivalry. Thus, molecules would form cells, neurons would form brains, species would form ecosystems, consumers and corporations would form economies, and so on. At each level, new emergent structures would form and engage in new emergent behaviors.”)

Evolutionists debate about what the fundamental level of natural selection and evolution is. Is it the organism, the gene…? I can easily agree that this basic level, wherever it lies, is characterized by randomness. What fascinates me is the properties that emerge at a “higher” (no moral value judgment applied with that word) level as a result of those random interactions at the fundamental level.

There seems a very obvious feedback loop at the level of a species interacting with its environment over hundreds of thousands of years. If a species interacts with its environment in such a way that continually depletes the resources that species needs for its survival, that species will eventually go extinct. On the other hand, if a species develops an interaction with its environment that nourishes cause and effect relations that eventually renew or even enhance aspects of the environment the species is dependent on, then the species can exist for a long time. Its position grows more secure. Therefore, over time, ecosystems will accumulate such species.

The most obvious examples of such species are plants that harvest sunlight and convert it into structures whose decay forms soils which alter the flow of water and nutrients in a way that allows the existence of even more plants. “Ecological Service” (the current phrase for the concept that species have influences that help create and maintain ecosystems) is easy to see in plants because they capture energy from outside the Earth and make it available on Earth. Ecological service is harder to see with animals because their influence can’t be a simple energy one. Their metabolism requires them to deplete energy within the ecosystem so any nourishing influence they exert must involve indirect effects or complex interactions of multiple causes and effects involving many other organisms.

The August 17, 1996 Science News had a fascinating article titled “Shrimp make intricate seabed labyrinth.” While scuba diving off Italy, a scientist noticed small volcano-like cones all over the bottom. When local people could give her no information about them, she began investigating. The mounds were made by 2 cm long mud shrimps. The “tunnels provide a chemical connection between sea and sediment….Without the shrimp and its tunnels,…oxygen would penetrate only about 4 millimeters into the ocean floor. With them, oxygen travels more than half a meter down, allowing even tinier oxygen-breathing animals to populate the holes….Ammonium from decaying organic matter buried in the sediment flows through the system to the water above, helping to nourish phytoplankton–and thus the entire oceanic food chain.”

“Ocean gophers,” I thought. When I learned ecology, the three concepts used to describe a species’ place in the world were range, habitat, and niche. I’m starting to think we need a fourth description: its gift. What gift does this species bring to the ecosystem that helps nourish (rather than consume) that species’ position within that ecosystem. This concept of gift intertwines with niche but it is different and more provocative. This “gift hypothesis” creates an interesting assumption for looking at the world. It does not imply that all species have such gifts; some species might be simply passing through in a short-term consumption of a non-renewable resource. It also does not imply universal cooperation and synergy. The ecological service of some species might compete with the ecological service of others. In very anthropocentric terms, different groups of organisms might be working towards different visions of what kind of ecosystem they want this particular piece of the world to be like. Nevertheless, at the ecosystem level, I can’t help but see a very strong selection against those species that simply consume resources with no compensating service to the ecosystem.
 
 

Let me use a metaphor to illustrate how random actions at one level can contain a direction at another level. When a raindrop falls straight down and splashes against the ground, it splatters soil particles randomly in all directions. This might compact the soil but in terms of movement of soil particles in any one direction, the splattering is random. The movements caused by one drop cancels out the movements of others.

However, if the rain is falling on a slope, then a non-random factor comes into play even though the splattering of raindrops remains random. Those soil particles splattered downhill will travel further than those soil particles splattered in the uphill direction. So, at the raindrop level, the direction of splattering remains random but the influence of slope will “differentiate” between movements in certain directions from which emerges a net downhill movement from all the raindrops. So, in the same way, natural selection might be directionless at the gene or organism level but the influence of nutrient flows and such through ecosystems will differentiate between species that have different influences on their environment from which emerges a net movement towards the evolution of “gifts”.

The idea of gift relates to a thought I’ve had while taking school classes out on the Redding Arboretum. Kids aren’t very interested in learning just the names of species. They need a story, a plot within which the species fits, to hold the species in the mind. Discovering the gifts of different species helps us learn many of these stories. When bioregionalists talk of reinhabiting the land, I’m sure part of what they have in mind is coming to know the stories of these gifts.
 
 

One of the people disagreeing about direction declared that “evolution is random and we are just animals.” The more we learn about ecological service and all the miraculous creation brought into existence by life, the more I feel proud to take my place next to the other animals. There is nothing “just” about them. To say we are “just animals” is like saying we are “just angels”. One of the reasons I preach on this is because the assumptions with which we view our relationship with the world will shape our actions within the world which will shape the evolution of the world which will shape our assumptions with which we view our relationship with the world. In other words, there is a feedback loop between our beliefs and our actions that can work for creation or destruction. This conflict was dissonantly expressed by two clippings that came my way. The first was a summary of Aldous Huxley’s Perennial Philosophy. Huxley maintained that all of the great religions shared four central doctrines that he labelled the Perennial Philosophy. The four doctrines are:

1. The material world is a manifestation of the Divine Ground from which it derives its being.

2. Human beings are capable of a direct experience of that Divine Ground, in such a way that the knower unites with the known.

3. Human Beings have a double nature, a temporal ego and an eternal self. The eternal self is the divine spark within each of us which we can identify with at any time.

4. Human life on earth has but one true purpose: to identify with our eternal selves and seek out a unitive understanding of the Divine Ground.

Contrast this purpose (“to identify with our eternal selves and seek out a unitive understanding of the Divine Ground”) with the implied purpose in the following two quotes from “Too Many People? Not by a Long Shot”, an editorial in the Wall Street Journal by Steven Mosher, president of Population Research Institute. The author is lamenting declining birth rates.

“But this “birth dearth,” as Ben Wattenberg has called it, has now spread well beyond the developed world. There are now 27 “developing” countries where women are averaging fewer than 2.2 children. These include such unlikely candidates as Sri Lanka and Thailand. The human face of this population implosion is melancholy–villages bereft of children, schools closed for lack of students–and the economic consequences are grim: Labor shortages cramp production, the housing market grows moribund, and this in turn creates a drag on real estate and other sectors of the economy.”

And a little later on… “Humanity’s long-term problem is not going to be too many children, but too few: too few children to fill the schools and universities, too few young people entering the work force, too few couples buying homes and second cars. In short, too few consumers and producers to drive the economy forward.”

That last paragraph is saying that humanity’s long-term goal is to drive the economy forward. And yet the ecological implications of a constantly growing population are so well-documented–whether it be mice or deer or people. A constantly growing population is an ecological impossibility. It ravages the ecosystem until the declining ecosystem can’t support the population growth and the population is brought to check, usually through great misery. This seems so obvious that I am forced to conclude that the author is blinded by the short-term profits to be made from a spree of selling cars and homes for a few decades. And how could such profits outweigh the destruction of God’s creation? Only if one has no sense of the divine and so sees life only in terms of the sensual pleasures of consumption and status. How pathetic this vision is, especially when compared to Huxley’s summary: to identify with our eternal selves and seek out a unitive understanding of the Divine Ground.