Mechanisms Of Evolution

Front 1

Genetic drift, population bottlenecks, and founder populations all illustrate __________.

Back 1

A.
decreasing population size has a greater effect on changing allele frequencies than increasing the population size

B.
that reducing population size will likely decrease genetic variability within the population

C.
the strong role played by very small isolated populations in the creation of new species.

Front 2

Gene flow __________.

Back 2

Makes populations more genetically similar

Front 3

What type of natural selection favors individuals with rarely encountered traits over individuals with traits that are frequently encountered?

Back 3

disruptive selection

Front 4

Body size varies among individuals in a species of lizard in the genus Aristelliger. Small lizards have a hard time defending a territory, and thus mating, but large lizards are more likely to be preyed on by owls. Therefore, natural selection favors individuals with an average body size. This is an example of _________.

Back 4

stabilizing selection

Front 5

Natural selection acts (through predation) against banded water snakes on certain Lake Erie islands, favoring the uniformly light-colored snakes. The banded form is very common on the nearby mainlands. Yet banded snakes are maintained in the island populations and not eliminated completely. This is probably due to _________.

Back 5

gene flow

Front 6

Selection against individuals at both ends of a phenotypic distribution for a character, favoring those in the middle or average of the distribution, is an example of __________.

Back 6

stabilizing selection

Front 7

Genetic drift will tend to __________.

Back 7

decrease genetic variability within populations but increase genetic variability between populations

Front 8

The process by which two species evolve adaptations in response to one another, such that evolutionary change in one species produces an evolutionary change in the other is called _______.

Back 8

coevolution

Front 9

Evolution is best defined as a change in __________.

Back 9

allele frequencies

Front 10

Provide one example each of bottleneck or founder effect. How do these two terms differ?

Back 10

Similarities: Both are types of genetic drift. In both, the genetic diversity within the population is decreased.

Differences:
**Bottleneck: all but a few of the initial population are eradicated by a chance event.
**Founder Effect: Founder effect is the result of a small population moving to a new, many times isolated, location.

Front 11

What is the primary difference between genetic drift and natural selection?

Back 11

Genetic drift is based on random changes in populations, not on reproductive success. Natural selection is based on reproductive success.

Front 12

In a mainland bird population, most individuals are black in color, and gray is a rare variation. A small group of these birds is carried by strong winds to a distant island, where they establish a new population. After a few generations, the gray phenotype is very common. What is most likely to be responsible for this?

Back 12

genetic drift

Front 13

Which of the following is a correct statement of evolution?

Back 13

A.
Natural selection is a mindless, mechanical process.

B.
The changes that we see in an individual as it grows and develops are not evolutionary changes.

C.
Heredity plays an important role in the theory of evolution by natural selection.

D.
Evolution is a property not of individuals but of populations.

Front 14

A population of insects, newly introduced to a forest, is adapting to different breeding sites: females can lay their eggs either on mushrooms on the forest floor or on the fruits of trees. In time, one group has adapted to the mushrooms, and another to the fruit. What type of selection drove these adaptations?

Back 14

disruptive selection

Front 15

Which phrase best describes the concept of natural selection?

Back 15

reproductive success

Front 16

What is a gene pool?

Back 16

All the genes in a population.