Microevolution Mechanisms and Effects

The video tutorial by Cherise covers microevolution, focusing on natural selection, genetic drift, and gene flow. Natural selection is explained as a process where organisms with advantageous traits reproduce more successfully, leading to adaptive evolution. Genetic drift is described as random changes in allele frequencies, particularly in small populations, with examples like the founder and bottleneck effects. Gene flow involves the movement of genes between populations, reducing genetic differences and affecting adaptation. The video emphasizes how these mechanisms contribute to microevolution.

What are the three main causes of microevolution?

• Genetic drift, mutation, and recombination

• Mutation, recombination, and selection

• Natural selection, genetic drift, and gene flow

• Speciation, adaptation, and mutation

How does natural selection affect a population?

• It decreases the population size

• It increases genetic variation

• It selects traits that are less suited to the environment

• It favors organisms with traits better suited to their environment

What is adaptive evolution?

• Evolution that results in a worse match between an organism and its environment

• Evolution that results in a better match between an organism and its environment

• Evolution that decreases the genetic variation in a population

• Evolution that increases the population size

What is the founder effect?

• A large population is reduced by a catastrophic event

• A population undergoes natural selection

• A few individuals start a new population with different allele frequencies

• A population merges with another population

What is the bottleneck effect?

• A population experiences an increase in genetic variation

• A population is split into two separate populations

• A population experiences a severe drop in size due to a catastrophic event

• A population undergoes rapid growth

What is a negative consequence of the bottleneck effect?

• Increased population size

• Enhanced natural selection

• Increased genetic variation

• Loss of genetic variation

What is the primary effect of genetic drift in small populations?

• It increases genetic variation

• It causes allele frequencies to change randomly

• It leads to adaptive evolution

• It prevents natural selection

How does gene flow affect populations?

• It increases genetic differences between populations

• It reduces genetic differences between populations

• It causes populations to become extinct

• It decreases the population size

What happens when two populations merge due to gene flow?

• They share a common gene pool

• They experience a bottleneck effect

• They form a new species

• They become more genetically distinct

Which of the following is NOT a mechanism of microevolution?

• Natural selection

• Speciation

• Gene flow

• Genetic drift