Wednesday, January 22, 2014

Molecular Clocks

Clocks are handy devices that have been around since the sixteenth century. They consist of two hands: the short hand dictates the minute of the day, and the long hand determines the minutes. Although the time of day may dissent from country to country, clocks are universal instruments that tick at a motleyless aim; time is consistent and does non speed up, nor does it slow down. The inconsistent range of the ticking of the clock, is angiotensin converting enzyme of the many reasons why the theory of Molecular Clocks is so contr all oversial. The molecular(a) clock theory, based on the neutral theory, uses the mutations that go across in proteins and DNA to determine when similar species diverged from individually varied in the evolutionary timeline (Cawley, 1998). In our debate, we will let off how the molecular clock theory is flawed and why it is not affectional as a universal tool to report evolutionary lineages. The molecular clock hypothesis assumes th at the rate of amino acidic or nucleotide substitutions is constant over evolutionary time. However, no gene or protein evolves at a constant rate because the function of a gene is likely to change over that time, particularly when the number of genes in the genome increases from simple organisms to colonial ones or when environmental conditions change (Nei, Kumar, 2000). DNA evolution rates too vary from species to species. For example, research done at the Massey University in cutting Zealand shows that the Tuatera and Arctic Penguins have the highest molecular evolutionary rate compared to opposite physicals such as bears and horses with a much drawn- surface molecular evolutionary rates (Mullen 2003). There are as well animal species where information on their DNA is very minimal. A modern research project in California, bar-coded bird DNA, canvas the differences in the sequences of Marsh jenny wrens to identify different subspecies. In this process, four new subspeci es of Marsh Wrens were discovered (Wade, 200! 4). This proves that thither are some species out there that have...If you want to get a full essay, sight it on our website: BestEssayCheap.com

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