Natural Selection

Natural selection occurs because of all of the following EXCEPT –

• more organisms are produced than can survive.

• the resources that organisms need are limited.

• organisms in a population show variation.

• some populations are related to others.

Over time, a species of mammals living in cold environments may evolve longer fur. This is due to the action of natural selection. Which of the following best describes how natural selection creates this adaptation?

• Mammals with slightly longer fur have a survival advantage.

• Mammals in colder climates produce more offspring.

• Cold climates stimulate the growth of longer fur in mammals.

• Individuals with longer hair migrate to colder climates.

Long term environmental change to an area is likely to create selective pressure that will –

• mutate the genetic makeup of organisms

• influence adaptations of populations over time.

• cause a decrease in reproductive rates.

• allow organisms to select the best adaptations.

The frequency of a certain trait in a population of beetles will increase over time if –

• there is variation in that trait within the population.

• beetles possessing the trait produce more offspring

• the trait is not linked to the genetic makeup of the beetle.

• it creates a specialization to a specific food source.

Which of the following characteristics of a population will make it better able to adapt to environmental changes?

• Rapid production of many offspring.

• Specialization in one type of food source.

• Large amount of inherited genetic variation.

• Isolation to a limited geographic range.

The mating call in a population of birds can evolve over time, so long as all of the following are true EXCEPT –

• there is variation in mating calls within the population.

• the mating call is determined by genes that are passed on.

• certain mating calls provide a reproductive advantage.

• a mating call attracts predators as well as potential mates.

Natural selection pressures will be greater in situations where which of the following is true?

• Resources are limited.

• Populations reproduce slowly.

• Population vary genetically.

• Competition is minimal.

Which of the following is an example of natural selection producing diversity between species?

• The webbed feet of ducks and the long legs of egrets were selected for by the water habitat of both kinds of bird.

• Mountain lions and foxes in the same prairie both have four limbs, because they share a common ancestor.

• Within a population of fish in a coral reef, there are two varieties with two distinct patterns of coloration.

• Zebras and gazelles have adaptations for running because they are both the prey of lions in the savannah.

In order for natural selection to have produced the long necks of giraffes, which of the following must have been true over the evolutionary history of giraffes?

• The length of necks in giraffe offspring was always longer than both parents.

• In every generation, the length of giraffes’ necks showed variation.

• All giraffes, regardless of neck length, had an equal chance of survival.

• Abundant resources insured that competition among giraffes was limited.

Animals in a moist and humid environments are specifically adapted to that habitat. Which of the following contributed to nature’s selection of these adaptations?

• Populations of animals have little variation.

• Animals produce very few offspring.

• The habitat provides abundant resources.

• Some adaptations offer survival advantages.