Differing Rates of Evolutionary Change and Common Misconceptions

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Evolutionary Time Scales EVOLUTIONARY time scales are difficult to comprehend from a human perspective; resultantly, anthropocentric conceptions of time have perverted evolutionary theory. Evolution is seen by laymen as a generational process - a process pondering the question: if the offspring of sexual organisms are always different from their parents, why does speciation only take place over many thousands of generations? Speciation - even adaptation for that matter - cannot be viewed in this microcosmic scope. For the purpose of this paper, speciation will be defined as the elimination of any "potentiality for interbreeding among members" of non-conspecific groups (Daly & Wilson, p70). Adaptation arises by the "trial and…show more content…
Thus, only minor genotypic novelties are likely to become adaptations; hence, adaptation can only occur with minor changes in an environment (Kawecki, p2-4).<p> One significant concession, however, must be interjected here: minor genotypic changes sometimes result in major phenotypic changes. The issue here concerns "regulatory genes:" genes controlling the specific intervals of, and duration of, maturation periods in an organism. An organism that matures differently can undergo tremendous phenotypic alteration. For example, since human and chimpanzee genomes are 99% alike, it has been hypothesised that the mere 1% difference contains a regulatory gene. Regulatory genes are, perhaps, the greatest accelerator for the evolutionary pace; however, these genes, like all other genes, are subject to an organism's environment: they are just as likely to be overwhelmed by the genetic tyranny of the majority. In short, since the potential for any genetic novelty occurring and radiating is low, the likelihood for a specific genetic novelty (an altered regulatory gene) occurring and radiating is lower.<p> Adaptation, further slowing evolutionary velocity, functions by trial and error (Wright, p25), not, as Lamarck would argue, by intentional adaptation to an environment (Wright, pp232-234). A deer straining its neck to eat berries on high branches, for example, will be no more

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