Environment for Evolution

For evolution to occur, there must be a convergence of many factors. There must first of all be an environment that is both diverse enough to allow natural experimentation, but homogeneous enough to keep conditions stable for huge periods of time. Earth’s environment, although it can be, relatively speaking, fairly harsh, is a magnificent balance of climatic elements.

Man’s understanding of his own evolution from the backdrop of life on his home planet has been generally a late blossom on the tree of knowledge. The idea in one form or another had been floating around for a few generations, but it first emerged with a vengeance in the middle of the 19th Century, with Darwin’s publication of The Origin of Species. Darwin knew nothing about genetics as we have since come to understand that system, but he knew traits were heritable, and he knew that slight drifts in the life stream could end up not too far downflow with considerable variation. He made the inference that the kicker in the process was a preferential handing on of traits which made it more likely for individuals to reproduce.

Human evolution has not been “proven” as a “scientific fact,” but the evidence for it is so overwhelming that there are few serious thinkers who uphold other theories. There are three major bases for the evolutionary conclusion: 1) the paleological evidence for man’s ancestry, 2) the continuity of man with the biological stream on earth, and 3) growing insight into the power of information bearing in the genetic system.

The fossil record goes back about 5 million years, when lines of ape and hominid descent diverged. Australopithecus,which was the first of the primates to walk on two f eet, was small brained and short of stature. Homo Habilis, at least 2 million years ago, showed marked expansion of the brain. The first hominid known to have migrated off the African continent was Homo Erecuts, about 1 1/2 million years ago. Neanderthal Man emerged ca. 250,000 years ago, to be edged off the scene by Cro-Magnon Man (our modern relative) some 30 to 50 thousand years before current time.

We are clearly variants of mammalian life forms, on so many levels that mere coincidence is an impossibility. The more we know about biology, the more this becomes apparent. Nowhere is this more critically apparent than in the central nervous system, where our brain, enclosed in our bony skull, is completely analogous with that of our animal relatives. Sensory and motor components are similarly located and similarly structured. The variation lies in the huge development in the human brain of associational areas required to support our higher intellectual function.

The more we know about genetics only deepens insight into the evolutionary process. The DNA double helix is beyond doubt the ladder used by life to climb upwards into greater bioflexibility and breadth of consciousness. Knowing little about the system, Darwin hypothesized chance variation as the prime mechanism for change within species. Generally, the idea of experience as such being able to influence inheritance, known as Lamarckism, has been discountenanced. Continuing work with genetics, as we learn more about possible feedback mechanisms, may show that rethinking in this area may be required by emerging fact.

The known feedback mechanisms identified at the present time show immense sensitivity. Biostructural gradients in developing organisms affect the expression of genetic instructions through messenger RNA. It is quite possible that analagous messages may be returned to germ plasm via serum proteins. At this point, this is hypothetical, but possible avenues for its occurrence have been well demonstrated. And, the more we learn, the more we wonder at the capacities of our internal bioinformation systems.

On a macro level, all life forms – including ourselves – have come into existence via gradual development. Biological process brings about variations in individuals and groups – those changes which are consistent with reproductive success tend to become part of the inheritance of the species. Over time, species change and new species develop. This is the essence of Darwin’s insight into Natural Selection.

We can only faintly imagine the implications of this for external information systems, which clearly are themselves developing at breakneck speed.

FEEDBACK – THE HEART OF IT

Feedback is a central component of biological systems. The essence of biological feedback (biofeedback) is that the rate or expression of a process is regulated by information reverberated back from its area of operation. Blood pressure is a prime example. If the blood pressure gets too high or too low, there are sensing organs which tell the body to up- or down-regulate its controlling activities. Similar systems work in most biological areas: blood sugar, muscular tension, sound recognition, and so on.