An endangered species of wildflower has been reduced to a single small population in a mountain meadow. An early spring blizzard buries and kills all but three of the remaining plants, one of which has a rare allele. The resulting evolutionary change in the population is an example of:

Parallel Evolution

Explanation:

It is because only three members are normal while one of them has a rare recessive allele. Due to parallel evolution, the recessive allele will now  become common as the other previously distinguished dominant alleles and now all the traits will be in a uniform equilibrium according to Hardy-Weinberg Theorem.

Bottleneck/ genetic drift

Explanation:

Bottleneck can be described as a situation whereby a  population of an organism is negatively affected through some certain events such as uncontrollable hunting of the specie,  destruction of habitat or environmental circumstances or disaster, and results to a reduction of the population.

Bottleneck is known to be a type of genetic drift, and its effect drastically reduces the population size of an organism. It also brings about a random change in the frequency of the alleles, which can be described as an evolutionary change.

In this case, what caused a reduction and evolutionary change of species of wildflower to mountain meadow is bottleneck.

69 is the correct math for the amino acids