Evolution: The Mindless Mechanism Life began on earth 3.5 billion years ago with the presence of primitive single-celled organisms. It is from these organisms that all life evolved. Species diverge from one another through mechanisms of change such as mutation, migration, genetic drift, and natural selection. Though a mechanism of change, natural selection does not strive for perfection. Rather, it is a process resulting from variation in heritable traits. A mindless mechanism with no objective, natural selection does not provide organisms with what they need, but instead selects for traits that allow an organism to produce the most viable offspring in a given environment. (Reece) All species arise from a pre-existing species. Cladogenesis
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These criteria can be influenced by factors such as migration or genetic drift. Migration of individuals into a population can convey a large impact. As new gene frequencies are introduced into a population, new gene combinations may either benefit a species or “break up ‘good’ combinations of genes” (Than). Genetic drift, random variation in the number of allele frequencies in a population, is another mechanism of evolution. Most significant in small populations, genetic drift can lead to the loss of genetic variation as well as cause harmful alleles to become fixed within a population …show more content…
In reality, natural selection results from “variation, differential reproduction, and heredity – it is mindless and mechanistic. It has no goals; it is not striving to produce “progress” or a balanced ecosystem,” (Than). Natural selection is not goal oriented, but it is also not random; variations that aid the viability of a species tend to be selected for more than variants that do not (Than). As selection occurs among variations that are present in a population, the resulting evolution can cause speciation (Reece). Speciation refers to the differentiations within species, caused by the mechanisms of evolution, which cause branching to occur and new species to arise when they can no longer interbreed in nature (Reece). Speciation occurs due to geographical isolation, gene flow, and pre-zygotic and post-zygotic
These criteria can be influenced by factors such as migration or genetic drift. Migration of individuals into a population can convey a large impact. As new gene frequencies are introduced into a population, new gene combinations may either benefit a species or “break up ‘good’ combinations of genes” (Than). Genetic drift, random variation in the number of allele frequencies in a population, is another mechanism of evolution. Most significant in small populations, genetic drift can lead to the loss of genetic variation as well as cause harmful alleles to become fixed within a population …show more content…
In reality, natural selection results from “variation, differential reproduction, and heredity – it is mindless and mechanistic. It has no goals; it is not striving to produce “progress” or a balanced ecosystem,” (Than). Natural selection is not goal oriented, but it is also not random; variations that aid the viability of a species tend to be selected for more than variants that do not (Than). As selection occurs among variations that are present in a population, the resulting evolution can cause speciation (Reece). Speciation refers to the differentiations within species, caused by the mechanisms of evolution, which cause branching to occur and new species to arise when they can no longer interbreed in nature (Reece). Speciation occurs due to geographical isolation, gene flow, and pre-zygotic and post-zygotic