Genetic drift is an important process that can change the genetic makeup of a population, moving it away from something called Hardy-Weinberg equilibrium. This concept helps scientists understand how genes are distributed in a population under certain conditions. For Hardy-Weinberg equilibrium to work, five things have to be true:
When these conditions aren’t met, especially the one about population size, genetic drift can happen.
So, what is genetic drift?
It's the change in how often certain genes appear in a population just by chance. This effect is stronger in smaller groups. For instance, in a small group of 100 individuals, random events can cause big changes in gene frequency. Studies have shown that gene frequencies can change by more than 20% in just one generation because of genetic drift.
In small populations, genetic drift can lead to two main effects:
Loss of Genetic Variation: Some genes can become very common (frequency = 1), while others can disappear completely (frequency = 0). For example, in a group of 50, if gene A has a frequency of 0.6, it can become the only gene present through luck, which reduces diversity.
Bottleneck and Founder Effects: Sometimes, a population may shrink a lot or new groups may form, causing different sets of genes to appear. For instance, in the Northern Elephant Seal case, a major reduction in population size led to a group that had less than 20% of the original genetic diversity.
Overall, genetic drift can greatly change populations over time, moving them away from Hardy-Weinberg equilibrium, creating some genes that are very common and losing genetic diversity.
Genetic drift is an important process that can change the genetic makeup of a population, moving it away from something called Hardy-Weinberg equilibrium. This concept helps scientists understand how genes are distributed in a population under certain conditions. For Hardy-Weinberg equilibrium to work, five things have to be true:
When these conditions aren’t met, especially the one about population size, genetic drift can happen.
So, what is genetic drift?
It's the change in how often certain genes appear in a population just by chance. This effect is stronger in smaller groups. For instance, in a small group of 100 individuals, random events can cause big changes in gene frequency. Studies have shown that gene frequencies can change by more than 20% in just one generation because of genetic drift.
In small populations, genetic drift can lead to two main effects:
Loss of Genetic Variation: Some genes can become very common (frequency = 1), while others can disappear completely (frequency = 0). For example, in a group of 50, if gene A has a frequency of 0.6, it can become the only gene present through luck, which reduces diversity.
Bottleneck and Founder Effects: Sometimes, a population may shrink a lot or new groups may form, causing different sets of genes to appear. For instance, in the Northern Elephant Seal case, a major reduction in population size led to a group that had less than 20% of the original genetic diversity.
Overall, genetic drift can greatly change populations over time, moving them away from Hardy-Weinberg equilibrium, creating some genes that are very common and losing genetic diversity.