<p>Back on topic, everyone.</p>
<p>
</p>
<p>Evolution is an empirically and objectively established phenomenon. Again, natural selection facilitates the process of evolution through the gradual accumulation of traits favorable to survival. This is predominantly accomplished through mutation, sexual reproduction, horizontal gene structure, and population dynamics. </p>
<p>Mutations (which creationists teach other to dispute in such conversations) are frequently rogue, which is frequently understood. But deleterious mutations are not selectively accumulated since, by their very nature, they are not conducive to survival/fitness or, more precisely, reproductive success, which is the most salient determinant of ecological vigor. In studies on Drosophila melanogaster, induced mutation has an undesirable effect approximately seventy percent of the time (since it fundamentally alters the product of a gene usually in adverse fashion), while such provides a neutral or weakly beneficial effect the remaining thirty percent of the time ([Source](<a href=“Inaugural Article: Prevalence of positive selection among nearly neutral amino acid replacements in Drosophila - PMC”>Inaugural Article: Prevalence of positive selection among nearly neutral amino acid replacements in Drosophila - PMC)</a>). Organisms with genetic material that rapidly facilitates evolution, such as viruses or any genetic structure with an RNA basis, will evolve constantly and rapidly. In the case of viruses, the rapid rate of mutation (and hence evolution) enables for evasion of the immune system. So why is it necessary to obtain a separate annual flu shot and why is it that the common cold plagues each individual on several many occasions throughout the course of a normal lifetime? Indeed, because of evolution that occurs on a level temporally identifiable relative to the lifespan of the typical human.</p>
<p>[Mutation</a> rates among RNA viruses ? PNAS](<a href=“http://www.pnas.org/content/96/24/13910.long]Mutation”>http://www.pnas.org/content/96/24/13910.long)</p>
<p>[Rapid</a> evolution of RNA genomes – Holland et al. 215 (4540): 1577 – Science](<a href=“http://www.sciencemag.org/cgi/content/abstract/215/4540/1577]Rapid”>http://www.sciencemag.org/cgi/content/abstract/215/4540/1577)</p>
<p>Mutations often consist of large sections of chromosomes becoming duplicated via genetic recombination, which inserts secondary copies of a gene into a genome. Additional gene copies are a significant source of the raw material requisite for new genes to evolve. In truth, most new genes evolve from a set of pre-existing biochemically similar genes that are orthologous to those held by common ancestors.</p>
<p>[Mechanisms</a> of change in gene copy number](<a href=“Mechanisms of change in gene copy number - PMC”>Mechanisms of change in gene copy number - PMC)</p>
<p>[ScienceDirect</a> - Journal of Molecular Biology : Studying Genomes Through the Aeons: Protein Families, Pseudogenes and Proteome Evolution](<a href=“http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WK7-462F332-2&_user=10&_coverDate=05%2F17%2F2002&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=da81eabcc96a597094e99ae91249d1d2]ScienceDirect”>http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WK7-462F332-2&_user=10&_coverDate=05%2F17%2F2002&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=da81eabcc96a597094e99ae91249d1d2)</p>
<p>Chromosomal mutation is precisely what facilitated the initial divergence of modern-day Homo sapiens from our chimpanzee predecessors, when segments of DNA broke and rearranged. The cumulative result was a fusion of chromosome 2, which manifested, over a period of time, the palpable genotypic discrepancies that disunited the two species. Chromosomal mutations serve to accelerate the divergence of populations by rendering populations less likely to interbreed, and hence preserve the genetic differences held between populations. </p>
<p>[Testing</a> the Chromosomal Speciation Hypothesis for Humans and Chimpanzees](<a href=“Testing the Chromosomal Speciation Hypothesis for Humans and Chimpanzees - PMC”>Testing the Chromosomal Speciation Hypothesis for Humans and Chimpanzees - PMC)</p>
<p>[Chromosome</a> speciation: Humans, Drosophila, and mosquitoes ? PNAS](<a href=“http://www.pnas.org/content/102/suppl.1/6535.full]Chromosome”>http://www.pnas.org/content/102/suppl.1/6535.full)</p>
<p>However, often many cannot grasp evolution simply because of the failure to understand the power of accumulation. I will permit myself a brief analogy to illustrate the fundamentals of evolution as if occurring over the course of a human lifespan. Chances are, anyone skimming through this post doesn’t fundamentally appear too much differently than he or she did yesterday. In fact, most of us have not had a profound alteration in physical appearance within the past year. However, if you compare your present appearance to your appearance sixty or seventy years from today, you are bound to appear a bit differently due to the cumulative effects of cellular oxidation, telomere shortening, metabolic accrual, and whatever else. It is virtually inconceivable to strictly pinpoint with a firmly evident degree of resolution when this aging precisely occurred. Similarly, it is difficult to specifically identify when one species originated or “officially” diverged from another. Likewise, one isn’t necessarily a completely transformed person when the clock strikes midnight on his or her eighteenth birthday (marking the “official” minor to adult change in many legal aspects) and has not exactly gleaned a greater degree of maturity to drive a car when one turns sixteen than one didn’t have at the age of fifteen and 364 days. So even if one day in the human lifespan is akin to 100 generations of biological existence, there should not be a drastic evolutionary difference in such a period (excluding momentous occurrences) – but there inevitably will be when distended over a significant period of time for the proper effects of accumulation to initiate and influence change.</p>