Let’s look at a couple of ideas yet, not so much to debunk specialness, but to continue the exercise of evolutionary logic, which really, now that Darwin has bequeathed it to us, is quite special, and natural selection has brought us the brain to work it!
Once the adaptive potential of auditory communication was broached – possibly by some of the first land animals (think of the well developed and varied calling of frogs), sound became a widespread method of communication in much of the terrestrial animal world. Reptiles are not noted for being voluble, but virtually all warm-blooded animals use sound extensively. In any case, the progression from simple signalling through basic communication, to language seems easily imaginable.
52 The argument would be the same as that for other evolved organs, such as the eye. The eye is an outstanding example of complexity, which many ‘intelligent design’ people seize upon because they could not see beyond the apparently intuitive, either you need a fully functioning eye or it is no use. But when you stop and think about it, every incremental step, every gain in visual acuity, (or in communication), however small, would be likely to confer survival advantages. There are continuums for both of these evolved capacities, with evolutionary advantage at each step of the way.
Yet another angle that is a real factor in evolutionary development: there are good reasons to believe that positive feedback mechanisms can contribute to relatively rapid and accelerating change. The very exercise of intelligence, like the use of many capacities, strengthens and promotes its further development. There is neuro-scientific evidence that the brain changes structurally in response to its use. This is, of course, not heritable since it is an acquired characteristic.43 But over generations it may factor into a positive feedback process whereby the more we use and benefit from our intelligence, the more selection pressure there is for high intelligence, which leads to higher intelligence, which leads to more opportunity to depend on intelligence, and so on in an accelerating spiral. Dawkins gives this sort of explanation some credibility. He calls it “self feeding co-evolution.” (1998, p 289) – or “the more you have the more you get.” His idea involves an arms race like relationship with competitors relating in ways that encourage certain developments in the other. In the case of the human brain development, the competitors may well have been other hominids. What happened to erectus and neanderthalensis? They were all exploiting this relatively new survival strategy called ‘intelligence.’ Were some more sapiens than others…?
Taking it just one more surprising, but plausible, step further, once language is
written, and the intelligences of individuals are thus joined, new and ever more rapid development of organisational and cultural complexity is made possible. It’s not hard to imagine that the evolutionary success of a species that reached these ‘mindmarks’ would accelerate dramatically – which is just what we have seen in Homo sapiens.
43
Refer to the ‘Baldwin Effect’ for a theory on how acquired characteristics and learning can affect evolution. (see Dennett 1995, pp 77–80)
I may not be right in many of the half-worked-out particulars I have here entertained, but unless I am drastically wrong, it appears almost certain, and much more plausible than a non-natural explanation, that natural processes have made us what we are.
As mentioned, the foregoing hypothetical reconstruction of the past is sometimes called a ‘just-so story.’ I suggest these attempts at explanation are better thought of as ‘thought experiments.’ They are based on some evidence, and follow a course consistent with evolutionary logic, employing ‘cranes,’ not ‘skyhooks.’ (Dennett 1995) In the ‘experiments’ I have constructed, I feel they help to imagine why we
appear so much more ‘advanced’ than our living relatives. In the end, if I am even close to right, it gives us many reasons to doubt that we are special in any significant way. The aim has not been to give the correct account of how we got to be more advanced than our living relatives, but rather, to show that it is possible to give a naturalistic explanation grounded in evolutionary thinking. While such explanations may occasionally seem wild and extraordinary (think of Miller’s hypothesis that basically the brain is like a peacock’s tail!), they have a kind of coherence and relevance that makes them very interesting indeed, and arguably helpful to a full understanding of Homo crdulus. Let’s give Daniel Dennett and humility the last word in this section:
There is simply no denying the breathtaking brilliance of the designs to be found in nature. Time and again, biologists baffled by some apparently futile or maladroit bit of bad design in nature have eventually come to see that they have underestimated the ingenuity, the sheer brilliance, the depth of insight to be discovered in one of Mother Nature’s creations. Francis Crick has mischievously baptized this trend in the name of his colleague Leslie Orgel, speaking of what he calls, “Orgel’s Second Rule: Evolution is
cleverer than you are.” (1995, p 74)