Competition, natural selection

The argument so far has been highly abstract and general, because it is intended to be valid fora number of selection mechanisms. It applies to the biological theory of natural selection, where it first arose, but also to the theory of economic competition, the theory of unconscious motivation and the theory of computer chess programs. Before I consider the first two in more deuil, I shall digress for a moment and say a few words about the relation between biology and the social sciences. 

Fig. 9 One of the vesicle models (as depicted by the SCM). Different templates (labelled by open and closed circles) contribute to the well being of the compartments (protocells) in that they catalyse steps of metabolism, for example. During protocell growth (-- ) templates replicate at differential expected rates, but stochastically. Upon division (- ) there is chance assortment of templates into offspring compartments. Stochastic replication and reassortment generate variation among protocells, on which natural selection at the compartment level can act and oppose to (correct) internal deterioration due to within-cell competition...

Historically, natural products have formed the oldest basis for new medicines, and natural selection during evolution and competition between the species has produced powerful, biologically active natural products. These can serve as chemical leads, to be refined by the chemist by creating analogues that will provide a more specifically acting drug, or perhaps avoid a delivery problem or an unwanted adverse side effect. 

EAs repeatedly carve up old members of the population to create fresh solutions. As in natural selection, competition within the population is essential, otherwise its evolution would be unpredictable and undirected, the algorithm would be as likely to retain poor solutions as promising ones and would make a lengthy and probably unproductive random walk over the search surface. Since individuals in the current population have evolved from those created in past generations, they reflect some of the lessons learned during previous attempts at solution. It is in this fashion that the algorithm learns about a problem. 

Two common processes - variation and selection - provide a powerful mechanism for self-replicating systems to evolve. For a system to evolve it must first display a range of variations. Natural systems display random variations through mutations, which are undirected changes in the chemical makeup of key biomolecules. Most variations are neutral or they harm the organism and are doomed to failure. Once in a while, however, a random mutation leads to an improved trait - a more efficient metabolism, better camouflage, swifter locomotion, or greater tolerance for extreme environmental conditions. Such beneficial variations are more likely to survive in the competitive natural world such variations fuel the process of natural selection. 

Competition drives the emergence of natural selection. Such behavior appears to be inevitable in any self-replicating chemical system in which resources are limited and some molecules have the ability to mutate. Over time, more efficient networks of autocatalytic molecules will increase in concentration at the expense of less efficient networks. In such a competitive milieu the emergence of increasing molecular complexity is inevitable new chemical pathways overlay the old. So it is that life has continued to evolve over the past four billion years of Earth history. 

HTid receptors. GR 127935 is somewhat selective for the S-HTinp over the 5-HTiua receptor [105] but the non-competitive nature of its antagonism of the dog isolated basilar artery preparation precludes a conclusion as to the exact subtype of 5-HTid receptor which subserves this effect. Nevertheless GR 127935 is now the best tool to define the presence of functional 5-HTiq receptors both in vitro and in vivo and will undoubtedly supersede the use of metitepine in this context. 

Perhaps now we can understand why intermediate forms of BU (the so-called missing links ) are not easy to find. If we suspect that two types of BU are related through natural selection, then the intermediate BU between these two forms would probably have been lost completely due to thdr competitive disadvantages. They would no longer exist, and their genetic material would survive only in changed form. 

Biodiversity is an essential element of a natural selection process in the face of continuous competition. Biodiversity is valuable for two reasons ... 

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