Chapter 4 Vocabulary

Question 1

Natural Selection

Answer 1

The mechanism for evolutionary change in which environmental pressures cause certain genetic combinations in a population to become more abundant; genetic combinations best adapted for present environmental conditions tend to become predominant

Question 2

Selection Presssures

Answer 2

Factors in the environment that favor successful reproduction of individuals possessing heritable traits and that reduce viability and fertility of those individuals not possessing those traits

Question 3

Critical Factor

Answer 3

The single environmental factor closest to a tolerance limit for a given species at a given time

Question 4

Tolerance Limits

Answer 4

(Also Limiting Factors)

Chemical or physical factors that limit the existence, growth, abundance, or distribution of an organism

Question 5

Indicators

Answer 5

(Also Indicator Species)

Those whose critical tolerance limits can be used to judge environmental conditions

Question 6

Habitat

Answer 6

The place or set of environmental conditions in which a particular organism lives

Question 7

Ecological Niche

Answer 7

The functional role and position of a species (population) within a community or ecosystem, including what resources it uses, how and when it uses the resources, and how it interacts with other populations

Question 8

Endemic

Answer 8

Not found anywhere else

Question 9

Competitive Exclusion Principle

Answer 9

A theory that no two populations of different species will occupy the same niche and compete for exactly the same resources in the same habitat for very long

Question 10

Resource Partitioning

Answer 10

In a biological community, various populations sharing environmental resources through specialization, thereby reducing direct competition

Question 11

Speciation

Answer 11

The generation of a new species

Question 12

Geographic Isolation

Answer 12

(Also Allopatric Speciation)

Species that arise from a common ancestor due to geographic barriers that cause reproductive isolation

Question 13

Allopatric Specieation

Answer 13

Species that arise from a common ancestor due to geographic barriers that cause reproductive isolation

Question 14

Sympatric Specieation

Answer 14

Species that arise from a common ancestor due to biological or behavioral barriers that cause reproductive isolation even though the organism live in the same place

Question 15

Binomials

Answer 15

Two part names (genus and species, usually in Latin) invented by Carl Linneaus to show taxonomic relationships

Question 16

Intraspecific Competition

Answer 16

In a community, competition for resources between members of a different species

Question 17

Interspecific Competition

Answer 17

In a community, competition for resources among members of the same species

Question 18

Predator-Meditated Competition

Answer 18

A situation in which predation reduces prey populations and gives an advantage to competitors that might not otherwise be successful

Question 19

Coevolution

Answer 19

The process in which species exert selective pressure on each other and gradually evolve new features or behaviors as a result of those pressures

Question 20

Batesian Mimicry

Answer 20

Evolution by one species to resemble the coloration, body shape, or behavior of another species that is protected from predators by a venomous stinger, bad taste, or some other defensive adaptation

Question 21

Mullerian Mimicry

Answer 21

Evolution of two species, both of which are unpalatable and, have poisonous stingers or some other defense mechanism, to resemble each other

Question 22

Symbosis

Answer 22

The intimate living together of memebers of two different species; includes mutualism, commensalism, and, in some classifications, parasitism

Question 23

Mutualism

Answer 23

A symbiotic relationship between individuals of two different species in which both species benefit from the association

Question 24

Commensalism

Answer 24

A symbiotic relationship in which one member is benefited and the second is neither harmed nor benefited

Question 25

Parasitism

Answer 25

A symbiotic relationship in which one member benefits and the other is harmed

Question 26

Keystone Species

Answer 26

A species whose impacts on its community or ecosystem are much larger and more influential than would be expected from mere abundance

Question 27

Primary Productivity

Answer 27

Synthesis of organic materials (biomass) by green plants using the energy captured in photosynthesis

Question 28

Abundance

Answer 28

The number or amount of something

Question 29

Diversity

Answer 29

The number of species present in a community (species richness), as well as the relative abundance of each species

Question 30

Complexity

Answer 30

The number of species at each trophic level and the number of trophic levels in a community

Question 31

Edge Effects

Answer 31

A change in species composition, physical conditions, or other ecological factors at the boundary between two ecosystems

Question 32

Ecotones

Answer 32

Boundaries between two types of ecological communities

Question 33

Climax Community

Answer 33

A relatively stable, long-lasting community reached in a successional series; usually determined by climate and soil type

Question 34

Primary Succession

Answer 34

An ecological succession that begins in an area where no biotic community previously existed

Question 35

Secondary Succession

Answer 35

Succession on a site where an existing community has been disrupted

Question 36

Pioneer Species

Answer 36

In primary succession on a terrestrial site, the plants, lichens, and microbes that first colonize the site

Question 37

Disturbance

Answer 37

A periodic, destructive events such as fire or floods; changes in an ecosystem that affect (positively or negatively) the organism living there

Question 38

Disturbance-Adapted Species

Answer 38

Species that depend on disturbances to succeed