Natural Selection Explanation Essay
Selina Gunsauls
Hasten
Anthropology 1
17 March 2017
Natural Selection Explanation
A species is a group of individuals that produces fertile offspring.
A population is a group of the same organisms or species.
The main source of genetic variation is meiosis. Within meiosis, fertilization occurs and creates variation. Within meiosis, although it is rare, mutations happen which can be also a source of variation. Gene flow, the movement of genes within multiple populations is another source of variation as well. Variation plays the role of making different traits in populations to lead to favorable and non-favorable traits to the environment which natural selection and selective pressure acts upon in the process of evolution. Variation is important
for the survival of a species because if all species were exactly the same they would be susceptible to the same diseases which could lead to extinction.
The interaction between variation and the environment leads to adaptation by positive and negative selective pressure. Individual populations will adapt by attaining new traits through variation. The more a trait works in a good way with its environment the more it become prevalent as positive pressure affects it. The less a trait is beneficial in an environment the less prevalent it becomes and can eventually disappear because of negative selective pressure.
Fitness, in Darwin’s terms, is determined based on an organisms ability to reproduce successfully. Fitness is wrongly and commonly defined as being stronger or more powerful because of the misused phrase of “survival of the fittest”. His definition differs from the common definition because it relates to reproduction not strength or physical traits. “Survival of the fittest” is incorrect in interpreting Darwin’s theory because it doesn't reflect the necessary aspect of fitness being about reproduction and not ones traits.
Hasten
Anthropology 1
17 March 2017
Natural Selection Explanation
A species is a group of individuals that produces fertile offspring.
A population is a group of the same organisms or species.
The main source of genetic variation is meiosis. Within meiosis, fertilization occurs and creates variation. Within meiosis, although it is rare, mutations happen which can be also a source of variation. Gene flow, the movement of genes within multiple populations is another source of variation as well. Variation plays the role of making different traits in populations to lead to favorable and non-favorable traits to the environment which natural selection and selective pressure acts upon in the process of evolution. Variation is important
for the survival of a species because if all species were exactly the same they would be susceptible to the same diseases which could lead to extinction.
The interaction between variation and the environment leads to adaptation by positive and negative selective pressure. Individual populations will adapt by attaining new traits through variation. The more a trait works in a good way with its environment the more it become prevalent as positive pressure affects it. The less a trait is beneficial in an environment the less prevalent it becomes and can eventually disappear because of negative selective pressure.
Fitness, in Darwin’s terms, is determined based on an organisms ability to reproduce successfully. Fitness is wrongly and commonly defined as being stronger or more powerful because of the misused phrase of “survival of the fittest”. His definition differs from the common definition because it relates to reproduction not strength or physical traits. “Survival of the fittest” is incorrect in interpreting Darwin’s theory because it doesn't reflect the necessary aspect of fitness being about reproduction and not ones traits.