Introduction
Charles Darwin’s Theory of Evolution may have been controversial, but it has survived to the present. His ideas on how living things have evolved through generations is still being subscribed to by modern scientists to explain how things came to be and how these will continue to exist centuries from now. The following paragraphs will describe several key terms in evolution and discuss how these concepts relate with each other.
Concepts and Processes
Species is “the smallest working units in biological classification; reproductively isolated populations or groups of populations capable of interbreeding to produce fertile offspring” ( Haviland, et al. 33). The number of individuals within the species or group is called the population. There are four forces that contribute to how species evolved. These are natural selection, mutation, random genetic drift and gene flow. In natural selection, different environmental factors come into play to produce the best offspring; one species may thrive better in a certain environment making it able to sustain its number over the next generations. In mutation, there are changes that happen in the living thing’s DNA. These changes affect all aspect of that organism including its offspring, thus there is a new variation in the species. Genetic drift happens when there are “chance fluctuations of allele frequencies in the gene pool” (42). When the genes migrate from one population and goes to another population, then that is called gene flow. Within populations, variations may occur and this may be any of the three kinds: phenotypic variation, fitness variation or inheritance.
Populations may also be isolated from one another. Isolating mechanisms may be geographical, ecological or behavioural. For example members of the species may not be able to meet because there is a geographical barrier such as living in different islands, then there would be no breeding between them. The ecological isolation may happen among similar species but those occupying different habitats. The last isolating mechanism may be behavioural wherein members of the same species are attracted to certain characteristics exhibited by a select few members of the population. The result of any of these isolating mechanisms is speciation, a very long process that creates new species because the populations have remained in isolation.
Conclusion
The concepts in evolution is not limited to the explanation of how man came to exist in the world. The enumerated terminologies are being used to define processes that take place everyday. These concepts are particularly important in the study of different organisms, particularly those that affect the human race, such as tropical diseases and finding a cure.
Works Cited
Haviland , William A., Prins , Harald E.L., Walrath, Dana, and Mcbride, Bunny. The Essence of Anthropology, Third Edition. USA:Cengage Learning, 2012.
