Part 7: Evolution
As we said in the last part, the best way to make choices among the repertoire of human behavior is to use the methods of science. We don't have to invent science from scratch: archeologists have been digging where people lived for thousands of years, and feel they understand the way we behaved. As far as we can tell there were three general periods which were characterized by different styles of behavior:
the paleolithic, in which we survived by gathering and hunting, and which lasted 50,- to 100,000 years;
the post-Neolithic, in which we practiced agriculture, and which lasted 8- to 10,000 years, and
the Industrial, which has lasted the last 500 years or so and in which we made extensive use of technological devices.
In the paleolithic we organized ourselves into small, conformist groups; in the post-Neolithic we created urban structures with a hierarchical organization. The industrial era may only have been a transition that might yet return us to the egalitarian organization of the paleolithic but on a global, rather than tribal, basis; but we can't be exactly sure how we will get past the present period of regression. It may be that the whole time since the Neolithic Revolution was a transition period between two stable periods, the paleolithic and post-Industrial, but we won't be sure of that, either, for a while.
In any case the most stable period we know of, and the one least influenced by the accidents of technological development, is the paleolithic; so we can use that to provide the key to the systematics of human behavior.
Unfortunately, we can't observe ourselves in a paleolithic state. Peoples that still live in a hunter-gatherer economy are to some degree in contact with modern technology, even if that is only through the use of metal implements. What we can do is find a theory of evolution that will describe human development from the most primitive cultures to the present, and see if that will give us some indication of what the fundamentals of behavior are like.
There are three models of evolution that can be applied to human behavior. All claim to be scientific, but only one is accepted by academic students of evolution: the Spencerian model based on "Survival of the Fittest".
In the New York Times of January 13, 2007, Dr. Michael Tomasello, the co-director of the Max Planck Institute for Evolutionary Anthropology wrote: "Evolutionary theory tells us that, in general, the only individuals who are around today are those whose ancestors did things that were beneficial to their own survival and reproduction". This is a weak form of Spencer's "Survival of the Fittest".
He also wrote:"We are still a long way from figuring out why humans evolved to do so many complicated things together: from building houses to creating universities to fighting wars."
There is a distinct difference between science and ideology and it is demonstrated by these quotes. We can be grateful that Dr. Tomasello was naive enough to see nothing wrong in what he said. If the Spencerian model was actually judged by scientific criteria it would have been junked because it doesn't explain cooperation, the primary basis of human survival. It is accepted because it allows academics to believe that they are superior to (i.e., "fitter" than) their students and the student's parents. Unfortunately, what they are "fitter" at is surviving in the academic bureaucracy.
Non-academics who don't feel inferior to academic bureaucrats have no way of responding except through religion. The model based on the creation of all present living forms by an "intelligent designer" who also created artificial fossils to be a practical joke on paleontologists is primarily a religious model, but it makes an argument that sounds scientific when it says that complex forms will not evolve without special creation. It does have the advantage that it doesn't say academics are fitter than non-academics.
Those are the two models that have the benefit of any noticeable public relations effort.
The third model is based on Darwin's initial concept: "Non-survival of the unfit". It isn't popular with academics or fundamentalists.
This phrasing makes it seem like it states the same principle as Spencer's model, but we will see that there is a significant difference. If we put it in the same form as Spencer's model it is: "Survival of the Just-Barely-Fit and Fitter". That shows the difference: Spencer's model says that the only individual that survives is "The Fittest"; whereas Darwin's model speaks to the survival of a substantial fraction of the breeding population. Since this is what normally happens, it is clear that Darwin's model is more descriptive of experience than Spencer's.
We can represent the way evolution works by considering Fig. 1.
A prey animal will be less likely to be found if it is colored like the environment: if it is too light or too dark it will be seen too easily.
But even if it is seen it may survive if it can run faster, but if it is structured to run too fast it will need more calories to survive so it will have to expose itself more often.
This will produce a "survival zone" in the space whose dimensions are coloration and speed. Individuals from any part of the zone may meet and their offspring may fall within the zone and survive to have offspring of their own, or outside the zone and leave no offspring. In the long run this will let the whole survival zone be populated with individuals whose offspring have a chance to survive.
In real life the survival zone will be multidimensional, with as many dimensions as there are qualities that affect the probability of survival. However, we can only conveniently illustrate a two-dimensional zone. Fortunately that illustrates the principle well enough.
Figure 2 shows the case where the environment is intolerant of variation in one dimension: if the environment changes in that direction none of the then present generation will survive. This is what happens when a species goes extinct.
If the environment changes there is no provision exept extinction under the Spencerian model because the individual who is "fittest" in the original environment, i.e., the one who best fits that circumstance, is not likely to be the "fittest" in the changed environment. Therefore the only things that survive a change in the environment according to the Spencerian model are those whose environment does not change.
In other words, under Spencerian evolution, all the creatures that still exist are those whose environment never changed. Since even the creationists believe in the flood, it is unlikely that the environment all over the earth never changed.
Let us consider a species that is more tolerant of environmental changes. This is represented by Fig. 3.
In equilibrium, the survival zone will be filled with individuals who are just barely able to survive or fitter. If the environment changes, there will be some individuals who will not be able to survive, but there will be others who will survive more easily.
Eventually the relocated survival zone will fill. If the environment continues to change, as long as it changes less than the dimension of the survival zone in a generation, the survival zone will continue to be filled. It is thus possible to reach a changed population that is different enough from the original population as to constitute a new species.
In some cases the survival zone will expand, for instance when a flood connects two bodies of water or a land bridge opens up. In the period after that the new survival zone will fill up with as many variations on the original population that will just barely survive in the new zone, as shown in Fig. 4.
This provides an explanation for the variety of creatures in the Burgess shale, an explosion of varieties in a newly opened environment. That would not happen under the Spencerian model because none of the variants would be "the fittest" in the original environment.
This provides the difference between the Spencerian and Darwinian models with regard to variations and mutations. In the Spencerian Model a mutation cannot survive unless the mutant is is "the fittest" in its present environment; but in the Darwinian Model the mutation merely needs to be barely able to survive in either the original or the changed environment.
Let me emphasize:
A Spencerian mutant has to have an immediate advantage in order to survive;
a Darwinian mutant merely has to avoid being significantly damaged in order to survive.
Notice that a Darwinian mutation can be carried in a population for generations before it provides a survival advantage.
In fact this shows that complexity, by itself, has an evolutionary advantage, because a complex structure can tolerate many more variations that may not be immediately advantageous but do no particular harm.
In addition, this provides an explanation for the advantage of cooperative behavior. Cooperation increases the survival zone for the breeding population, even if it does not provide a competitive advantage for a particular individual. Cooperation, and even altruism, are survival qualities for a population. There are animals that survive as individuals, but there are also many animals that live in groups and derive a survival advantage from that behavior. This is consistent with the Darwinian Model but not with the Spencerian Model.
The Intelligent Design Model is unnecessary because the Darwinian Model provides for complexity of form without the assumption of a supernatural designer. The Spencerian Model is unscientific because it does not explain phenomena like the Burgess Shale and cooperation as well as the Darwinian Model. But why do these models retain their popularity?
The Spencerian Model is popular among academic, and other, bureaucrats because it provides a justification for hierarchical systems. That allows the bureaucrats to consider themselves superior (i.e., more "fit") than the people they are supposed to serve. It also provides a justification for racism and classism.
Similarly, Intelligent Design provides a basis for belief that the status quo was created by a divine fiat, and that therefore those in high status were placed there by divine decree.
The Darwinist Model explains that all the individuals in a breeding population contribute to its survival, so that democratic rather than feudal institutions are more "natural".
It will, therefore, be difficult to get people in authority in the present bureaucratic systems to adopt the Darwinist Model as "scientific". It does, however, provide an explanation for the evolution of human behavior.