Question

Which mechanism of evolutionary change is random?

		gene flow
		natural selection
		genetic drift
		sexual selection

Which mechanism of evolutionary change results in a population that is better fit for current environmental conditions?

		sexual selection
		genetic drift
		gene flow
		natural selection

1. Researchers studying polymorphic garter snakes to test whether predation patterns by birds helped to influence the snake’s color pattern. They created clay models of snakes (both striped and melanistic) and looked to see how many of the models were attacked by birds. The table below represents the data:

Month	Striped Attacked	Striped Total	Melanistic Attacked	Melanistic Total
May	15	60	10	60
June	2	60	2	60
July	4	60	4	60
August	5	60	8	60

2. Present this data in graphical form and explain why you chose the particular graph type. Be sure to label your axes.
3. You will need to either use excel or hand-draw your figure, then save the file and upload it in your answer. If you have trouble, then you can just email the figure to me.

Based on the figure you drew, does bird predation appear to explain why garter snakes are polymorphic? Explain.

Does the likelihood of allopatric speciation higher or lower when the splintered population is small and isolated? Explain.

Describe a situation in which adaptive radiation would be likely to occur.

Answer 1

Answer 1) option 3. Genetic drift.

Genetic drift is the mechanism of evolutionary change that is random.
Genetic drift is a completely random process in which alleles survival depends on the chance where as natural selection depends on environment for survival.
While gene flow is a process of transferring of genes from one population to another.
In sexual selection there is preferance of character of one sex by another sex.

Answer 2) option 4. Natural selection.

Natural selection is the mechanism of evolutionary change that results in a population that is better fit for current environmental conditions.
In natural selection the organism that adapt to the environment more easily are better at survival.