preview

Characteristics Of Functional Variability Among Organisms

Decent Essays

The essential sources of functional variability among organisms are the changes that arise from mutations in their genes. Charles Darwin introduced the concept of evolution as a driving force for life through natural selection in his book On the Origin of Species in 1859. Sharing a common ancestor, all life on earth experienced natural selection as a “gradual process by which heritable biological traits become either more or less common in a population [2]”. About a century later, the cumulative work of biologists led to the understanding of the responsible chemical compounds of these hereditary traits. Deoxyribonucleic acid or DNA carries almost all the genetic information of living things on Earth and is the molecular blue print for all known life (note: some viruses uses Ribonucleic acid RNA instead). The DNA is a linear sequence that exists in a complex structure that comprises two long stretches of nucleotides, which are twisted into a double helix. Each nucleotide could be one of four different chemical bases: guanine (G), adenine (A), thymine (T), or cytosine (C). To produce any protein within a cell, each of three consecutive chemical bases, which represent a codon, are transcribed to RNA molecules and then translated into amino acid, the building blocks of any protein. Zucrenrkandl and Pauling [3] classified DNA as semantide molecules or information carriers, while RNA and amino acids were classified as secondary semantides, as a result of both the transcription and

Get Access