anthropologySample Essays

Sample Essay on Four Forces of Evolution

Four Forces of Evolution

The field of study attempting to explain evolution through genes and genotypes transformation within a population is known as evolutionary genetics. The field as well covers processes altering variations within a population into a less or more variation enduring among species. Species refers to a group of organisms with the capability of exchanging genes amongst themselves but they cannot exchange with other sets. Variation refers to traits difference between parents and off springs or individuals within the population. Evolution is transformation in inherited characteristics of a population which occurs through allelic frequencies changes or traits changes of any population through generations. In this respect, there are 4 evolutionary forces that act between and within population leading to microevolution. These 4 forces include genetic drift, natural selection, gene flow and mutation (Wade, Evolution Genetics).
Natural selection refers to ecological process through which organisms that are best adapted produce the highest number of offspring. The offspring possess genes give them upper edge. Nature has some forces that make it possible for some organisms to survive while making it difficult for others. Traits that can provide the advantage of survival are preserved by nature and passed to the next generation while organisms that have harmful traits die eventually. Genetic drift refers to a stochastic progress through which chance plays the role of making a decision on the gene variant that will survive. This often happens within smaller populations. For example, in meiotic reduction division where the alleles turn it into a germ is by random nature (Swaddle, Evolution).

Genetic flow (migration) occurs whenever genes interchange from one population to another. Organisms might migrate from one population to another. When migrants mate with natives, it leads to birth of a new gene in the already existing pool. For instance, when pollen grain gets blown to a region where it was not present, it introduces new genetic materials to that region/population. Mutation refers to the process through which transformation contributes to transition in equation changes. In genetics, it refers to the changes that result from DNA modification. This occurs as a result of substitution, deletion or replication of the base pairs.
Mutation refers to definitive source of some new genetic variation in a population. There are some mutations which are dangerous; others do not have any effect while still others tend to be favorable to fitness. Such variants are important for purposes of adaptive evolution. In a population that is predetermined, natural selection and genetic drift affect mutational variations. Selection also produces adaptability, the fit link organism and surroundings as well as conservation of genetic state for long periods on drift forces and mutation. Hereditary variations are also affected by variation converse to those that result from genetic drift. Population deviation is restricted by migration and this impedes speciation course.
Speciation is progression through which a parent species gets transformed into becoming a more descendant or one species. It happens when barriers segregate members of a population from each other. The Geographic or Allopatric speciation occurs as a result of physical population isolation. Sympatric speciation on the other hand occurs within the same area as a result of changes in genetics. Speciation might also be the result of reproductive segregation mechanisms. These are reproductive traits stopping species from fusing and being able to effectively breed. They are classified as post-mating isolation and pre-mating mechanisms. In cases of pre-mating isolation, species are prevented from forming reproductive and hybrid zygotes. These include temporal, ecological mechanical and behavioral isolations. Post mating organisms on the other hand ensure abnormal development, zygotes fails and they do not have the ability to interbreed. These include hybrid inviability, gametic incompatibility, hybrid breakdown and hybrid sterility (University of Michigan, process of Speciation).
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