General Ecology Chapter 3

Question 1

Balancing selection

Answer 1

type of natural selection that maintains genetic diversity in a population

Question 2

Balanced polymorphism

Answer 2

where 2 or more alleles or morphs are maintained in a population

Question 3

Disruptive selection

Answer 3

favors the survival of individuals at both extremes of a range rather than the intermediate

Question 4

Biological Species Concept

Answer 4

defined species as groups of populations that can actually or potentially exchange genes with one another and that are reproductively isolated from other such groups

Question 5

Phylogenetic species concept

Answer 5

advocates that members of a single species are identified by a unique combination of characters

Question 6

Evolutionary species concept

Answer 6

species is distinct from other lineages if it has its own evolutionary tendencies and historical fate

Question 7

Allopatric speciation

Answer 7

involves spatial separation of populations by a geographical barrier

Question 8

Sympatric speciation

Answer 8

occurs when members of a species that initially occupied the same habitat within the same range diverge into two or more different species

Question 9

Continental drift

Answer 9

the slow movement of the Earth’s surface plates

Question 10

Convergent evolution

Answer 10

leads to emergence in each realm of herbivores and predators that have evolved from different taxonomic ancestors

Question 11

Red Queen hypothesis

Answer 11

describes evolutionary history of life as a continual race with no winners, only losers

Question 12

Gradualism

Answer 12

new species evolve continuously over time

Question 13

Punctuated equilibrium

Answer 13

the tempo of evolution is more sporadic

Question 14

The birth weights of human babies generally lie in the range of 3-4 kg (6-9 lbs). Mothers cannot deliver much bigger babies, and small babies tend to have increased mortality. This is an example of:

Answer 14

Stabilizing selection

Question 15

The biological species concept is based on species’:

Answer 15

Reproductive isolation

Question 16

In what geological period did most phyla on Earth arise?

Answer 16

Cambrian

Question 17

The original supercontinental landmass present 280 million years ago was called:

Answer 17

Pangaea

Question 18

The gradual movement of the Earth’s landmasses across the surface of the world is known as:

Answer 18

Continental drift

Question 19

The biogeograhic realm that incorporates South America is known as:

Answer 19

Neotropical

Question 20

Most recorded extinctions have been caused by:

Answer 20

Introduced species and Habitat destruction

Question 21

Elimination of native species by introduced species has been commonly caused by:

Answer 21

Predation and Parasitism and disease

Question 22

As a percentage of prescribed species, which taxa is currently threatened most with extinction?

Answer 22

Amphibians

Question 23

Which of the following characteristics increase a species sensitivity to extinction

Answer 23

Increased rarity