Genetic drift is the spread of specific random variations throughout the gene pool in the absence of specific selection pressures. There's always random variation in the population, but there aren't always changes in the environment for the population to adapt to. So natural selection, in stead of moving the population towards adaptation, might select from that random variation to move 'sideways', as it were, to a state that's equally well-adapted to the environment as what came before, but different. As random variation may produce many variants that are, more or less, equally well-adapted to their environment, the direction of evolution that results is more or less random.
In terms of a population, evolution is just the change of allele frequencies over time. Natural selection can cause certain advantageous alleles to increase in frequency, and detrimental alleles to decrease in frequency.
Evolution changes the relative frequency of alleles in a gene pool through mechanisms such as natural selection, genetic drift, gene flow, and mutation. These processes can cause certain alleles to become more or less common in the population over time, leading to changes in the genetic makeup of the population. This happens because individuals with beneficial alleles that help them survive and reproduce are more likely to pass those alleles on to the next generation, increasing their frequency in the gene pool.
Genetic drift may occur when a small group of individuals colonizes a new habitat. These individuals may carry alleles in different relative frequencies than did the larger population from which they came.
increased genetic diversity within the population. This genetic diversity can help the population adapt to changing environments and increase its overall fitness. However, it can also lead to inbreeding depression if harmful genes are passed on through interbreeding.
D) the change in frequencies of alleles due to random events
Genetic drift is a major factor in evolution that refers to random changes in allele frequencies in a population over time. It can result in the loss of genetic diversity and the fixation of certain alleles, leading to evolutionary changes. In small populations, genetic drift can have a significant impact on the genetic makeup of the population.
Allele frequencies in a population refer to the proportion of each allele for a given gene among all alleles at that locus. Since all possible alleles at a locus contribute to the genetic makeup of that population, the sum of their frequencies must equal one, representing the entire genetic pool for that gene. This ensures that the distribution of alleles reflects the entirety of genetic variation available for that trait within the population.
Genetic drift can disrupt genetic equilibrium by causing random fluctuations in allele frequencies within a population. Over time, genetic drift can lead to the loss of alleles, reduced genetic diversity, and potential changes in the population's genetic composition, deviating it from equilibrium.
Random changes in allele frequency are due to genetic drift.
Random changes in allele frequencies in small populations are known as genetic drift. Genetic drift occurs due to chance events, leading to unpredictable fluctuations in the frequency of alleles within a population. In small populations, genetic drift can have a significant impact and may result in certain alleles becoming more or less common or even being lost altogether over time.
Genetic drift is a random process that can lead to fluctuations in gene frequencies within a population over time. It is more prominent in smaller populations where chance events can have a bigger impact. Over generations, genetic drift can lead to the fixation of certain alleles and the loss of others, resulting in changes to the genetic makeup of a population.
Migration can lead to changes in allele frequencies by introducing new alleles into a population. When individuals move between populations, they bring their genetic material with them, potentially altering the genetic diversity of the receiving population. Gene flow through migration can increase genetic variation within a population or decrease differences between populations.