Evolution & Fitness

Evolution is considered a theory because…

• It is a known fact

• Its beliefs are absolute and unchangeable

• It is a well-supported explanation, based on many observations

Which of the following is NOT an observation or inference on which natural selection is based?

• There is variation among individuals.

• Poorly adapted individuals NEVER produce offspring.

• Individuals whose characteristics are best suited to the environment generally leave more offspring than those whose characteristics are less well suited.

Which of the following is statements about the theory of evolution is false?

• Natural selection requires competition for food and space.

• Natural selection requires variation within the species.

• Traits causing variation are not inheritable.

Which of the following is true of evolution?

• Evolutionary changes increase the ability of a species to survive and reproduce in a specific environment.

• Evolutionary changes result in a species becoming more and more abundant over time.

• Evolutionary changes result in animals becoming larger over time and having larger numbers of offspring.

Which describes natural selection?

• Some live and some die in each generation

• Only the largest and strongest survive

• The best adapted individuals for the specific environment survive and reproduce, contributing the most to the next generation

Over a hundred year period, the use of a certain pesticide (kills insects) to control insects on cotton crops increases steadily.  What change would most likely result from this increase?

• Within the population, the amount of cotton fiber produced per plant would decrease.

• New varieties of cotton would evolve.

• Pesticide resistance in insects that eat cotton plants would increase.

1. Four female mice live in a beach area which is mostly tan sand with scattered plants.  According to the definition given for fitness, which mouse would biologists consider the fittest?  (a)  

• Black
• Tan
• Black and Tan

Which describes natural selection?

• Only the largest and strongest survive

• Random assortment of genes results in better characteristics in the following generations

• The best adapted individuals for the specific environment survive and reproduce, contributing the most to the next generation

In artificial selection, …

• The organisms best suited to their environment survive and reproduce the best.

• Environmental conditions determine the traits that get passed on to the next generations.

• Nature provides the variation and humans select which trait is the most beneficial for their purposes.