Bio Ch 17

Question 1

Macroevolution

Answer 1

evolution on a large scale

Question 2

Speciation

Answer 2

splitting of one species into 2 or more species; or transformation of one species into new species over time

Question 3

Taxonomist

Answer 3

scientist that classifies organisms into groups

Question 4

Species concepts

Answer 4

different ways in which a species is defined

Question 5

Morphology

Answer 5

species identified by differences in their appearance

Question 6

Morphological Species Concept

Answer 6

each species is defined by one or more distinct physical characteristics (diagnostic traits) that distinguish one species from another

Question 7

Diagnostic traits

Answer 7

distinct physical characteristics that distinguish one species from another

Question 8

Cryptic Species

Answer 8

species that look almost identical but are very different in other traits, such as habitat use or courtship behaviors

Question 9

Evolutionary Species Concept

Answer 9

proposed to explain speciation in the fossil record; relies on identification of certain morphological diagnostic traits to distinguish one species from another; requires that the members of a species share the same, distinct, evolutionary pathway

Question 10

Phylogenetic Species Concept

Answer 10

an evolutionary family tree (phylogeny) is used to identify species based on a common ancestor, that is, a single ancestor for two or more different groups

Question 11

Monophyletic

Answer 11

a branch that contains all of the descendants of a common ancestor; main criterion for defining species in the phylogenetic species concept

Question 12

Node

Answer 12

a phylogenetic tree term; point at which two branches or lineages intersect

Question 13

Root

Answer 13

a phylogenetic tree term; point to which all species in the phylogeny can trace their ancestry; the origin of their shared common ancestry

Question 14

Extinction

Answer 14

taxon that is represented in the fossil record but is no longer in it; represented by a shortened branch on the phylogenetic tree correlated with the time the ___ occurred

Question 15

Biological Species Concept

Answer 15

relies primarily on reproductive isolation rather than trait differences or shared evolutionary history to define a species

Question 16

Reproductive Isolation

Answer 16

physiological, behavioral, and genetic processes that inhibit interbreeding

Question 17

Prezygotic Isolation

Answer 17

reproductive isolation before fertilization

Question 18

Postzygotic Isolation

Answer 18

reproductive isolation after fertilization

Question 19

Zygote

Answer 19

first cell that results when a sperm fertilizes an egg

Question 20

Prezygotic Isolating Mechanisms

Answer 20

prevent reproductive attempts or make it unlikely that fertilization will be successful if mating is attempted

Question 21

Hybridization

Answer 21

mating between 2 species

Question 22

Habitat Isolation

Answer 22

when 2 species occupy different habitats, even within the same geographic range, they are less likely to meet and attempt to reproduce

Question 23

Temporal Isolation

Answer 23

several related species can live in the same locale, but if each reproduces at a different time of year, they do not attempt to mate

Question 24

Behavioral Isolation

Answer 24

many animal species have courtship patterns that allow males and females to recognize one another

Question 25

Mechanical Isolation

Answer 25

when animal genitalia or plant floral structures are incompatible, reproduction cannot occur

Question 26

Gamete Isolation

Answer 26

even if the gametes of 2 different species meet, they may not fuse to become a zygote

Question 27

Postzygotic Isolating Mechanisms

Answer 27

those that operate after formation of the zygote, preventing hybrid offspring from developing, even if reproduction attempts have been successful

Question 28

Hybrid Inviability

Answer 28

a hybrid zygote may not be viable, and so it dies

Question 29

Hybrid Sterility

Answer 29

the hybrid zygote may develop into a sterile adult

Question 30

Allopatric Speciation

Answer 30

eventual result of populations separated by a geographic or some other physical barrier

Question 31

Reinforcement

Answer 31

process of natural selection that reinforces reproductive isolation; occurs when 2 populations, formerly of the same species, come back in contact after being isolated

Question 32

Sympatric Speciation

Answer 32

speciation without the presence of a geographic barrier

Question 33

Polyploidy

Answer 33

a chromosome number beyond the diploid (2n) number; type of sympatric speciation

Question 34

Autoploidy

Answer 34

occurs when a diploid plant produces diploid gametes due to nondisjunction during meiosis

Question 35

Alloploidy

Answer 35

requires a more complicated process that autoploidy because it requires that two different but related species of plants hybridize; hybridization is followed by doubling of the chromosomes

Question 36

Adaptive Radiation

Answer 36

type of speciation that occurs when a single ancestral species rapidly gives rise to a radiation of new species as each adapts to a specific environment

Question 37

Ecological Release

Answer 37

freedom for a species to expand its use of resources within habitats where competition has been removed

Question 38

Convergent Evolution

Answer 38

said to occur when a similar biological trait evolves in 2 unrelated species as a result of exposure to similar environments

Question 39

Analogous

Answer 39

traits that evolve convergently in 2 unrelated lineages because of a response to a similar lifestyle or habitat (ex. wings of birds and bats)

Question 40

Homologous

Answer 40

traits that are similar because they evolved from a common ancestor

Question 41

Gradualistic Model of Evolution

Answer 41

proposes that speciation occurs after populations become isolated, with each group continuing slowly on its own evolutionary pathway

Question 42

Punctuated Equilibrium Model

Answer 42

assembly of species in the fossil record can be explained by periods of equilibrium (stasis), that are punctuated (interrupted) by periods of rapid, abrupt speciation, or change