Introduction
Evolutionary processes in nature involve constant mutational changes in the genetic makeup and the fixation of those traits that provide a survival advantage. Since the first organism appeared on the planet, evolution has continued, leading to development and speciation — as a result, all organisms that exist today can be considered descendants of the first living being. The differences at the phenotypic and genotypic level are due to different conditions of survival, interaction with the environment and differentiated nutrition. In this paper the evolutionary process will be considered in detail.
Evolution and Natural Selection
Evolution should be understood as the natural process of life’s development that leads to the fixation of traits that are advantageous for survival. Populations constantly undergo mutational changes, which can be negative or beneficial. However, mutations themselves are not the engine that drives the evolutionary process. On the contrary, mutations should be seen as the basis for natural selection. Natural selection is the reason for the fixation of beneficial mutations for the population, which leads to the development of species and speciation. Darwin’s postulated selection states that of two organisms, the one that is more adaptable to a given environment will survive: it follows that mutations that promote adaptability determine the possibility of survival (Darwin, 1987). Subsequently, if such a mutation is beneficial to the population, this trait will be perpetuated through reproduction and inheritance.
The Four Factors of Natural Selection
Natural selection is a complex tool for fixing beneficial mutations during the evolutionary process, which can be divided into four factors. The first is variability, which determines the presence of genetic mutations in an organism and in the gene pool of a population. Such mutations can have different genesis, from biogenic natural to those that occur due to external causes, including radiation exposure. Regardless of the cause, mutations affect the genetic integrity of the organism and can be inherited. Heredity is the second factor of natural selection, which characterizes the transfer of genes and changes between generations. For example, random DNA breaks in a parent’s body can be passed on to a child, just as a human child inherits genes from its parents. Third, differential reproduction ensures that some individuals have a greater chance of reproducing than others. The difference between these individuals is that those with traits that contribute to survival have a greater chance of reproductive success. Finally, the final factor of natural selection is adaptation, which ensures that certain traits become more common in the population over time, leading to adaptation to the local environment. For example, if a random trait of a butterfly that hides in trees allowed individuals to survive because birds could not see them, and that trait was inherited, then it is very likely that after some time the entire population will have that trait.
Male Competition
Evolutionary processes do not necessarily involve sexual reproduction: they apply to all forms of life, including microorganisms and plants that reproduce asexually. Sexual reproduction should be understood as a special form of natural selection, the variability and inheritance of which is determined by the mixing of male and female gametes, and thus their fusion, the combination of traits, and the potential for the emergence of new ones. Sexual reproduction, in contrast to asexual reproduction, is more closely associated with variability because it determines the processes of gene fusion and combination. At moments of such combinations, of which crossing over is an example, breaks or shifts in nucleotide sequences can occur, leading to the formation of new traits, helpful or harmful. Natural selection will preserve only those traits in a population that can contribute to survival.
Large Trunk Increases Reproductive Chances
It is important to emphasize that not all organisms in a population have an equal chance of reproductive success. The phenomenon of intraspecific — or more correctly, intrapopulation — competition results in some individuals being more attractive for mating. Unless one considers people, whose mating is associated with many social and cultural factors, and rarely based solely on biological reasons, organisms may choose some individuals over others. An example from Conboy’s (2013) video is Elephant seals (M. angustirostris), large seals with trunk-like noses that inhabit North American and Antarctic waters. It is noteworthy that the massive trunk is a feature of male Elephant seals; it is absent in females and immature males. The trunk can be considered an instrument of male competition in seals during the mating season (Taylor, 2017). The trunk is bled and swollen: the female will choose the male with the larger trunk. It is not uncommon for males to engage in bloody fights for females, and the surviving winner has the best chance of mating.
Conclusion
In summary, the evolutionary process never ends and is the natural progression of life. Mutation and inheritance, which are the basis for the accumulation of traits, allow individuals to differ within a population. Natural selection postulates that in the struggle caused by such differences, the organism with the greater adaptability, including mating conditions, will survive. Sexual reproduction is a particular example of natural selection, and for most living organisms it is characterized by the fact that there is a mating season. During such a period, females tend to choose males that are more attractive to them, which is determined by male competition.
References
Conboy, R. (2013). Evolution — why sex? — part 2 [Video]. YouTube. Web.
Darwin, C. (1987). Charles Darwin’s natural selection: Being the second part of his big species book written from 1856 to 1858. Cambridge University Press.
Taylor, B. (2017). Californian elephant seals: Models of sexual selection. NERC. Web.