Nature of Evolution Selection Inheritance and History (Essay Sample)

Nature of Evolution: Selection, Inheritance, and History
[Name of Student]
[Name of University]
Nature of Evolution: Selection, Inheritance, and History
According to Darwin’s ‘Panspermia’ perspective in the ‘Abiogenesis’ theory of the origins of species, all organisms descended from a common ancestral point before diversifying into billions of species (Rinaldi, 2011). Some of the original species have since become extinct while new ones have arisen with time. At the same time, others have continued to survive and develop better adaptive abilities to survive in their ecological habitats. All these processes get defined and explained by the theory of evolution. At all the levels of biological and morphological organization of organisms, changes in inheritable traits continuously lead to alterations of genetic and phenotypic characteristics (Casteren, 2011). Evolution defines an ongoing gradual process that leads to speciation, anagenesis, and extinction through mutation, gene flow, genetic drift, and natural selection.
Mutations occur when sequences of Deoxyribonucleic acids (DNA) undergo a spontaneous metamorphosis that alters their structural organization. Some mutations are harmless without any effects on involved organisms. However, others may boost or inhibit phenotypic abilities through various genetic influences. When mutations change protein-based chromosomal structures, the outcomes may be harmful and may result in various diseases (Sydow, 2012). However, other changes may enhance physical abilities, intelligence, and resistance to diseases. Subsequent mutations may lead to broadened limits of diversity to the extent new species may arise. They occur through the deletion, insertion, and substitution of sections of DNA structures. They can also occur as frameshifts that involve combinations of different base structures (Sorokhtin, 2011).
Evolution through natural selection depends on the existence of diversity within different populations. This process ensures that phenotypic and genotypic traits that aid continued existence within populations get enhanced while those that do not get reduced to the point of extinction. Because of variation, some organisms remain better adapted to survive compared to others. These organisms can obtain nutrition, protect themselves against predation, and resist diseases more effectively. Such abilities increase their chances of surviving to reproduction (Hall, 2011). On the other hand, the less able organisms stand lesser chances of getting to reproduction. In subsequent generations, such populations get to have more of the better-adapted organisms as opposed to the less adapted ones. Such organisms are then said to have been selected by nature (Casteren, 2011).
Both gene flow and genetic drift involve the introduction of new alleles that cause genetic modification and variation within populations. While the former occurs as a result of the migration of new members into and out of populations, the latter is typically an outcome of chance. Thus, if individuals migrating into a population introduce new alleles, the process gets referred to as gene flow (Rinaldi, 2011). On the other hand, there are occasions when some members of a population simply happen to leave more offspring than others. If no genetic process plays a role, the process gets referred to as genetic drift. Its effects remain more pronounce in small size populations. In both cases, subsequent populations present more effects of the altered tr...