On these pages we shall work towards a fully computational understanding of how a system may reproduce the meaningful and guided behaviour that the human mind exhibits, and how it may become sentient. To reach that end, we shall need understanding of the principles of that system, to be found in biology and philosophy, and as such we begin with the concept of evolution. The following history of the evolution of Dasein, the mind, has been kept as concise as possible and contains many background concepts necessary to support subsequent theory. In this first section we shall look at the physical developments of evolution, the nerves, senses and the brain, which are a prerequisite for the functional-cognitive adaptations that follow in the next two sections. Evolution The human brain is a product of evolution, and came into being in its current form, as part of our species, about 200,000 years ago; life on earth arose approximately 3.5 billion years ago. Life started with chemical compounds that could copy themselves automatically given the required materials were present in their environment. This copying is called replication, and these first compounds were the ancestors of what we call DNA. If a replicator was successful, it would flourish and produce many more copies. If another replicator, with perhaps an inefficient copy-mechanism, had difficulty reproducing itself then it might die out. This is the start of natural selection, where the replicator best suited to its environment is logically and practically more likely to survive; we say it is more fit. Now, these replicators would change; their code would be altered by mistakes in copying, or stresses suffered by the environment, this is mutation. These changes would then be subject to the natural selection just mentioned, and over generations these accumulated changes are called evolution. The replicators then grew larger, held more information, acquired fatty coats and became what we call cells. To be sure, smaller replicators are more efficient, they require less resources to copy themselves and so can sustain themselves in an environment of limited resources for a longer time. But, a larger replicator with more information is able to respond to a greater variety of external challenges and so is better suited to existence in a wider range of environments. Thus, the replicators diversified and adapted to different environments on the planet, and grew in size and cell number to cross the "boundaries" of these environments so that a larger number of resources would be at their disposal. The origin of the nervous system Within a multi-cellular replicator adjacent cells can communicate by chemical transfer; what is scientifically known as the active or passive transfer or diffusion or compounds between, and within, cells. The genetic code produces proteins, some that act as receptors and some, amongst other compounds, that act as messenger molecules, and in this way may detect and react to the environment in which they live. In a small replicator of, say, a few cells, this mode of communication is sufficient, efficient and timely enough for its purposes of survival to replication. But once a replicator consists of millions, billions or trillions of cells, such communication becomes, literally, fatally slow. Thus, some cells within such larger replicators, by the process of evolution, became messenger cells; long cells stretching within the body of the replicator that by transmitting a potential difference (electrical impulse) faster than the possible transport of the messenger compounds, could enable rapid reaction at far parts of the replicator in response to a stimulus or threat detected elsewhere. These cells are what we call neurons (within the brain) or nerves. The origin of the senses The senses began when replicators first acquired lipid membranes to make cells. Receptors on the surface of the cell would first function to regulate the concentrations of compounds and minerals within the cell, by transporting the relevant materials in or out, and so optimizing the lifespan and replicative potential of the cell. Once replicators acquired motility, some receptors would now function to guide, in a very rough way, the replicator towards areas of high concentration of the compounds required for its metabolism. This is the sense of smell. Then, perhaps, crude photo-receptors that could detect coarse differences in light developed to allow the replicator to find light and heat, or shade and cool, as required. This is the sense of sight. And so, gradually and in response to the diversity in and differences between environments, replicators evolved different ways to gather information on their surroundings, so that they might respond to their surroundings and thus maximise their replication efficiency; their chances of survival. The origin of the brain The brain is a very pragmatic response to the increase in neural complexity of the replicators brought about by their increased data collection; they needed a place to coordinate responses to the senses. Invariably, the brain is adjacent to the eyes, these sensors evolved to produce a relatively large amount of data, since there is more visual information to be gleaned from the environment, especially near the surface of the planet, and this data has advantages over the other senses; it is virtually instantaneous from a long distance, and tells the replicator more about the environment physically and practically than any other sense. Coupled with the increasing number of senses; hearing, touch, temperature, proprioception etc., the brain is the evolutionary response for the need to compare all data, "build an image" of the surroundings, and so coordinate a physical response that takes all these senses into account to ensure the best possible (re)action. This is the fundamental selective pressure of the brain. Summary
Created 27th June 2008 Revised 29th June 2009 |