Understanding genetic drift is important for knowing how evolution works. Here’s why it matters:
Random Changes in Allele Frequencies: Genetic drift means that changes in how often certain traits show up in a group can happen by chance. This is especially true in small groups. For example, if there are only 50 animals in a population, a specific trait might suddenly become very common or very rare just because of random events.
Founder Effects and Bottlenecks: Sometimes, a small group starts a new population. This is called a founder effect. Also, if a population gets really small due to a disaster, it’s known as a bottleneck. In both cases, the variety of traits can drop a lot. For example, today, cheetahs have only about 1% of the genetic variety that their ancestors had because of these effects.
Impact on Evolution: Genetic drift can change which traits become common or disappear over time, and this can happen without natural selection playing a role. For instance, in a group with 100 different traits, each has a 1 in 100 chance of becoming the most common trait just by chance.
Understanding these ideas is key to studying evolution because they help explain changes that don't always follow the usual patterns, like natural selection.
Understanding genetic drift is important for knowing how evolution works. Here’s why it matters:
Random Changes in Allele Frequencies: Genetic drift means that changes in how often certain traits show up in a group can happen by chance. This is especially true in small groups. For example, if there are only 50 animals in a population, a specific trait might suddenly become very common or very rare just because of random events.
Founder Effects and Bottlenecks: Sometimes, a small group starts a new population. This is called a founder effect. Also, if a population gets really small due to a disaster, it’s known as a bottleneck. In both cases, the variety of traits can drop a lot. For example, today, cheetahs have only about 1% of the genetic variety that their ancestors had because of these effects.
Impact on Evolution: Genetic drift can change which traits become common or disappear over time, and this can happen without natural selection playing a role. For instance, in a group with 100 different traits, each has a 1 in 100 chance of becoming the most common trait just by chance.
Understanding these ideas is key to studying evolution because they help explain changes that don't always follow the usual patterns, like natural selection.