Compare and contrast the terms in each of the following pairs: natural selection and genetic drift

Key Concepts

Natural Selection

Natural selection is a fundamental mechanism of evolution, proposed by Charles Darwin. It occurs when individuals with advantageous traits are more likely to survive and reproduce, passing those traits to the next generation. This process leads to the adaptation of species to their environments over time, as beneficial traits become more common within a population.

Genetic Drift

Genetic drift is a random process that can lead to changes in allele frequencies within a population, particularly in small populations. Unlike natural selection, which is driven by environmental pressures, genetic drift occurs due to chance events, such as random mating or catastrophic events. This can result in the loss of genetic variation and can significantly impact the evolutionary trajectory of a population.

Comparison of Mechanisms

While both natural selection and genetic drift are mechanisms of evolution, they operate differently. Natural selection is a non-random process that favors traits that enhance survival and reproduction, leading to adaptive evolution. In contrast, genetic drift is a random process that can lead to significant changes in a population's genetic makeup without regard to the adaptive value of traits, often resulting in neutral or even detrimental effects on fitness.