Question

Beech Bark Disease is a (mostly) fungal disease that was first observed in the US in NYC in the 1950's and is spreading south. It kills mature trees in as little as 5 years. As it spreads through the UGA Botanical Garden, the size of the beech population is reduced by 98%, leaving only the 2% of individuals that exhibit some resistance to the fungus. Over time the population increases to its original size. All of the individuals in the new population exhibit resistance to the fungus, but are more susceptible to root rot disease.

This story is an example of: (Mark all that apply or are described directly)

	Founder Effects
	Genetic Drift
	Natural Selection
	Genetic Bottleneck
	Reduced Genetic Diversity
	Evolution

Answer 1

The story is an example of all the options which are given

Founder effect, genetic drift , genetic bottleneck results in reduce genetic diversity. In the above scnerio -after the beech bark disease new population is establish by 2% of the original population.This will result in decrease in genetic diversity among the individuals of new population.hence, chances of individuals resistance to root rot diasease is very low.

This story can also be example of natural selection as nature selects only those individuals which has resistant against beech barch disease. All this phenomenon can leads to evolution of new species.

DEFINITIONS

Founder effect- loss of genetic diversity when new poulation is established by very small number of individual from larger population.

Genetic drift- is the mechanism of evolution in which allele frequencies of a population change over time due to chance.It reduces genetic diversity of population by fixing or loosing some allele.

Genetic bottleneck- phenomena in which size of the population drastically reduce to few individuals.It results in significant lose of genetic diversity.

Natural selection- process that results in the adaptation of the organism to its environment by means of selectively reproducing changes in its genetic composition.