Chapter 4 - Table 1-Table 1

Question 1

Directional Selection

Answer 1

Natural selection that drives evolutionary change by selecting for greater or lesser frequency of a given trait in a population.

Question 2

Stabilizing Selection

Answer 2

Selection that maintains a certain phenotype by selecting against deviations from it.

Question 3

Gene Flow

Answer 3

Movements of genes between populations.

Question 4

Inbreeding

Answer 4

Mating between close relatives.

Question 5

Genetic Drift

Answer 5

Random changes in gene frequency in a population.

Question 6

Founder Effect

Answer 6

A component of genetic drift theory, stating that new populations that become isolated from the parent population carry only the genetic variation of the founders.

Question 7

Genetic Bottleneck

Answer 7

Temporary dramatic reduction in size of a population or species.

Question 8

Sexual Selection

Answer 8

Differential reproductive success within one sex of any species.

Question 9

Sexual Dimorphism

Answer 9

Difference in size, shape, or color between the sexes.

Question 10

Reproductive Potential

Answer 10

The possible output of offspring by one sex.

Question 11

Reproductive Variance

Answer 11

A measure of variation from the mean of a population in the reproductive potential of one sex compared with the other.

Question 12

Systematics

Answer 12

Branch of biology that describes patterns of organismal variation.

Question 13

Homology

Answer 13

Similarity of traits resulting from shared ancestry.

Question 14

Analogous

Answer 14

Having similar traits due to similar use, not due to shared ancestry.

Question 15

Convergent Evolution

Answer 15

Similar form or function brought about by natural selection under similar environments rather than shared ancestry.

Question 16

Cladistics

Answer 16

Method of classification using ancestral and derived traits to distinguish patterns of evolution within lineages.

Question 17

Cladogram

Answer 17

Branching diagram showing evolved relationships among members of a lineage.

Question 18

Species

Answer 18

An interbreeding group of animals or plants that are reproductively isolated through anatomy, ecology, behavior, or geographic distribution from all other such groups.

Question 19

Speciation

Answer 19

Formation of one or more new species via reproductive isolation.

Question 20

Biological Species Concept

Answer 20

Defines species as interbreeding populations reproductively isolated from other such populations.

Question 21

Evolutionary Species Concept

Answer 21

Defines species as evolutionary lineages with their own unique identity.

Question 22

Ecoloigcal Species Concept

Answer 22

Defines species based on the uniqueness of their ecological niche.

Question 23

Recognition Species Conept

Answer 23

Defines species based on unique traits or behavirs that allow members of one species to identify each other for mating.

Question 24

Reproductive Isolating mechanisms (RIMs)

Answer 24

Any factor-beahvioral, ecological, or anatomical-that prevents a male and female of two different species from hybridizing.

Question 25

Anagenesis

Answer 25

Evolution of a trait or a species into another over a period of time.

Question 26

Cladogenesis

Answer 26

Evolution through the branching of a species or a lineage.

Question 27

Allopatric Speciation

Answer 27

Speciation occuring via geographic isolation.

Question 28

Parapatric Speciation

Answer 28

Speciation occurring when two populations have continuous distributions and some phenotypes in that distribustion are more favorable than others.

Question 29

Sympatric Speciation

Answer 29

Speciataion occurring in the same geographic location.

Question 30

Gradualism

Answer 30

Darwinian view of slow, incremental evolutionary change.

Question 31

Macroevolution

Answer 31

Evolution of major phenotypic changes over relatively short time periods.

Question 32

Punctuated Equilibrium

Answer 32

Model of evolution characterized by rapid bursts of change, followed by long periods of stasis.

Question 33

Adaptionism

Answer 33

A premise that all aspects of an organism have been molded by natural selection to a form optimal for enhancing reproductive success.

Question 34

Reductionism

Answer 34

Paradigm that an organism is the sum of many evolved parts and that organisms can best be understood through an adaptionist approach.

Question 35

Null Hypothesis

Answer 35

The starting assumption for scientific inquiry, that one's research results occur by random chance. Pme's hypothesis must challenge this initial assumption.

Question 36

Hardy-Weinberg Equilibrium

Answer 36

The theoretical distribution of alleles in a given population in the absence of evolution, expressed as a mathematical equation.

Question 37

Group Selection

Answer 37

Notion, largely discredited by the rise of Darwinian theory, proposing that animals act for the good of their social goruo or of their species.

Question 38

Kin Selection

Answer 38

Principle that animals behave preferentially toward their genetic kin; formulated by William Hamilton.

Question 39

Inclusive Fitness

Answer 39

Reproductive success of an organism plus the fitness of its close kin.