The Process of Natural Selection
To understand the process of natural selection, understanding the variation, competition and selection aspects will provide a better understanding of this process.
Variation:
Every individual within a population is different from each other in some way – the show variations. Some of these variations can provide an increased chance of survival or decreased chance of survival. In other words, some variations will provide either an advantage or disadvantage on an individual’s survival.
Individuals that possess a favourable variation/phenotype will have an increased chance of reproducing and passing on this variation/phenotype to their offspring. Inheritance of this trait will provide the offspring an increased chance of survival and hence reproduce passing on that variation/phenotype to the next generation. Over time and many generations, if this variation continues to provide an advantage for their survival. The individuals within the population showing the variation will increase chances of survival.
Individuals that have less favourable variations or that are not as well suited to their environment will not be able to compete as effectively. They are likely to die young and produce few or no offspring at all. They will have a limited contribution to the gene pool of the next generation resulting in a decrease in the number of individuals with that particular variation within the population.
Competition:
Individuals within a population are always competing each other for food, shelter and even their mating partner. In the end, those who have a selective advantage over other individuals will be able to compete for the resource.
In many situations, there are times in which individuals do not compete for resources, but are competing to not be eaten by a predator or killed by a particular disease. In this case, individuals with a particular variation that reduces their chance of being eaten or killed will have a higher chance of survival. Types of variations that would benefit these situations include colour variation – for camouflaging or variation in body behavior – Some animals, such as goats, freeze themselves to act as if they’re dead around predators.
Selection: Organisms live within ecosystems, which are made up of various biotic and abiotic factors. These factors contribute to selecting which variations provide the individual with an increased chance of surviving. It is for this reason that these factors may be referred to as selective pressures or selective agents – They are purposely chosen to reproduce based on their (favorable) traits. Biotic factors that may act as selective agents include predators, disease, competitors, prey and mating partners. Examples of abiotic factors include temperature, shelter, sunlight, water and nutrients.
Variation:
Every individual within a population is different from each other in some way – the show variations. Some of these variations can provide an increased chance of survival or decreased chance of survival. In other words, some variations will provide either an advantage or disadvantage on an individual’s survival.
Individuals that possess a favourable variation/phenotype will have an increased chance of reproducing and passing on this variation/phenotype to their offspring. Inheritance of this trait will provide the offspring an increased chance of survival and hence reproduce passing on that variation/phenotype to the next generation. Over time and many generations, if this variation continues to provide an advantage for their survival. The individuals within the population showing the variation will increase chances of survival.
Individuals that have less favourable variations or that are not as well suited to their environment will not be able to compete as effectively. They are likely to die young and produce few or no offspring at all. They will have a limited contribution to the gene pool of the next generation resulting in a decrease in the number of individuals with that particular variation within the population.
Competition:
Individuals within a population are always competing each other for food, shelter and even their mating partner. In the end, those who have a selective advantage over other individuals will be able to compete for the resource.
In many situations, there are times in which individuals do not compete for resources, but are competing to not be eaten by a predator or killed by a particular disease. In this case, individuals with a particular variation that reduces their chance of being eaten or killed will have a higher chance of survival. Types of variations that would benefit these situations include colour variation – for camouflaging or variation in body behavior – Some animals, such as goats, freeze themselves to act as if they’re dead around predators.
Selection: Organisms live within ecosystems, which are made up of various biotic and abiotic factors. These factors contribute to selecting which variations provide the individual with an increased chance of surviving. It is for this reason that these factors may be referred to as selective pressures or selective agents – They are purposely chosen to reproduce based on their (favorable) traits. Biotic factors that may act as selective agents include predators, disease, competitors, prey and mating partners. Examples of abiotic factors include temperature, shelter, sunlight, water and nutrients.