When studying the process of evolution, it is important to understand the basic concepts and, what is very important, the way these concepts are interrelated. It helps not just to learn how the evolution was progressing, but this knowledge will also create a strong basis for understanding this important and interesting science. This paper will focus on explaining the concepts of species, population, the Four Forces, variation, isolating mechanisms, and speciation.
In evolution species means such a lineage of organisms, in which genes are shared, maintaining integrity in relation to other lineages in space and time. At some point of time members of such group can change something about them and evolve into subspecies. As a result of this process, a new species can be formed eventually.
Population is a concept that is directly related to species, as it means all organisms that are in the same species, living in one geographical area. In case of defining sexual population, area means such a place where inter-breeding becomes possible between any two organisms within the place and cross-breeding is less possible with organisms from other places.
The four forces of evolution are the following: genetic drift, natural selection, gene flow and mutation. The first, genetic drift, means a certain change in gene variant frequency in some population because of random sampling. Gene variant frequency of population is copies fraction of a gene shared by a particular form. As for the second force, that is natural selection, it is a key force of evolution that means non-random, gradual process, in the course of which biological traits get more or less common in population.
Gene flow is the process of genes exchange between species or populations. Absence or presence of this process influences the evolution process fundamentally. The last force of evolution is mutation. It is an accidental change in the DNA genomic sequence caused by transposons, radiation, mutagenic chemicals, viruses and errors in the course of DNA replication or meiosis.
The concept of variation refers to variation in genes alleles that can occur among populations or within them. It is important, as it is closely related to the natural selection process, providing raw material for it. Between populations geographic variation takes place, which means genes variation among such populations that live in different areas. In one population variation is recognized at different levels. First, phenotypic one, is observed either in discrete features (color in flowers, for instance) or in quantitative (length of legs in cats). At enzymes levels it is identified through protein electrophoresis. The last type is variation of bases order in genes nucleotides.
Isolating mechanisms are certain traits of morphology, behavior, genetics serving to prevent breeding between various species. There are two groups of these mechanisms: postzygotic and prezygotic. Among the postzygotic mechanisms there are: hybrid sterility, hybrid inviability, hybrid breakdown and zygotic mortality. Prezygotic mechanisms involve: temporal, mechanical, ecological, geographic and behavioral isolation and gametic incompatibility (Hall 2011).
The last concept to consider is speciation, which is a process of new biological species formation. There are four speciation modes defined on the basis of populations’ isolation: parapatric, peripatric, allopatric and sympatric.
Based on the concepts analysis, I can say that their connection is evident and it is impossible to fully understand the evolutionary processes without knowing the basic concepts. They help to see the fundamental processes of the science, which is very important and interesting.
Works Cited
Hall, Brian. Evolution: Principles and Processes. Sudbury: Jones & Bartlett Learning, 2011. Print.
