Mechanisms of Evolution

Master evolution's driving forces: natural selection, genetic drift, and more!

Use this video to help you review the mechanisms of evolution. Match the term to its correct definition. Speciation The formation of a new species Founder Effect A few individuals move to a new area and start a new population Bottleneck Effect A random event greatly reduces a population size and leaves only a few individuals to rebuild the population Gene Flow The movement or introduction of genes from one population into another population Natural Selection The process of individuals who are better adapted to their environment tend to survive and reproduce more Genetic drift is the random event that changes allele frequencies within small popualtions. Select theTWOmechanisms that are classified as genetic drift. Founder Effect Natural Selection Mutations Gene Flow Bottleneck Effect During the bottleneck effect, a catastrophe wipes out a large amount of the population. The few remaining survivors must rebuild the population with only the genes that they have. How does the bottleneck effect change the genetic diversity of the population? Genetic diversity remains the same, which doesn't affect the population. Genetic diversity decreases, which is bad for the population. Genetic diversity increases, which is good for the population. Genetic diversity decreases, which is good for the population. During the gene flow, a few individuals are introduced to an existing population. This will likely introduce new genes to the population, which could be beneficial for natural selection. How does gene flow change the genetic diversity of the population? Genetic diversity remains the same, which doesn't affect the population. Genetic diversity decreases, which is bad for the population. Genetic diversity increases, which is good for the population. Genetic diversity decreases, which is good for the population. During the founder effect, a few individuals are relocated to a different area and they start their own population from scratch using only the genes that they have. How does the genetic diversity of the newly established population compare to the original population that they left? The new population has the same genetic diversity, which doesn't affect the new population. The new population has less genetic diversity, which is bad for the new population. The new population has more genetic diversity, which is good for the new population. The new population has less genetic diversity, which is good for the new population. Review the information provided in the data table and then answer the questions below. You do not have to fill out anything in the table. Data Population A Population B Population C Total # of flowers 1,000 250 3 # of different genes (colors) 9 6 2 1. According to the table, which population is the most genetically diverse? Population A Population B Population C 2. According to the table, which population is the least genetically diverse? Population A Population B Population C 3. Which population is more vulnerable (more likely to go extinct) if a genetic drift event occurs? Population A Population B Population C They are all equally vulnerable 4. Look at the data table above. Suppose a flood develops in the area of Population B and wipes out most of that population leaving only a small number of individuals. What type of event does this represent? Gene Flow Bottleneck Effect mutational disruption natural selection 5. From Population A about 100 individual plants are removed and transferred to a new location hundreds of miles away, and a new population forms. Which type of mechanism does this represent? Bottleneck Effect Founder Effect Gene Flow Mutations 6. How are mutations related to the process of evolution? mutations prevent the development of new species mutations provide genetic variations which can increase fitness mutations remove individuals who are not adapted to the environment mutations cause less genetic diversity in a population 7. Which of the following introduces new alleles into a population's gene pool and increases diversity? genetic drift natural selection gene flow mutations both C and D 8. Mutations are... always good for the population always bad for the population sometimes good and sometimes bad. It depends what type of environment the population inhabits.