CHAPTER 17

Question 1

macroevolution

Answer 1

large scale evolutionary changes

Question 2

speciation

Answer 2

a part of macroevolution that involves the formation of new species

Question 3

taxonomists

Answer 3

use one of three species concepts available to define species

Question 4

morphology

Answer 4

identifying species based on difference in appearance

Question 5

morphological species concept

Answer 5

species are distinguished from each other by 1+ distinct physical characteristics called diagnostic traits

Question 6

cryptic species

Answer 6

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

Question 7

evolutionary species concept

Answer 7

relies on identification of certain morphological traits to distinguish one species from another. proposed to explain fossil record

Question 8

phylogenetic species concept

Answer 8

an evolutionary family tree or phylogeny, is used to identify species based on common ancestor

Question 9

monophyletic

Answer 9

a phylogeny, a branch that contains all the descendants of a common ancestor, is said to be monophyletic

Question 10

biological species concept

Answer 10

relies primarily on reproductive isolation to identify different species

Question 11

reproductive isolation

Answer 11

the most important criterion according to the biological species concept. phyiological, behavioral, and genetic processes that inhibit interbreeding.

Question 12

zygote

Answer 12

The first cell that results when a sperm fertilizes an egg

Question 13

prezygotic isolating mechanisms

Answer 13

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

Question 14

hybridization

Answer 14

the mating between two organisms

Question 15

habitat isolation

Answer 15

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

Question 16

temporal isolation

Answer 16

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 17

behavioral isolation

Answer 17

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

Question 18

mechanical isolation

Answer 18

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

Question 19

gamete isolation

Answer 19

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

Question 20

postzygotic isolating mechanisms

Answer 20

operate after the formation of a zygote. these mechanisms prevent hybrid offspring from developing and reproducing

Question 21

hybrid inviability

Answer 21

a hybrid zygote may die because it is nnot viable

Question 22

hybrid sterility

Answer 22

the hybrid zygote may develop into a sterile adult

Question 23

speciation

Answer 23

the splitting of one species into two or more species, or the transformation of one species into new species over time

Question 24

allopatric speciation

Answer 24

is the eventual result of populations that have become separated by a geographic or other type of physical barrier

Question 25

reinforcement

Answer 25

given to the process of natural selection that reinforces reproductive isolation

Question 26

sympatric speciation

Answer 26

speciation that occurs in the absence of a geographic barrier

Question 27

polyploidy

Answer 27

a chromosome number beyond the diploid 2n number

Question 28

autoploidy

Answer 28

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

Question 29

alloploidy

Answer 29

occurs when two different but related species of plants hybridize

Question 30

adaptative radiation

Answer 30

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

Question 31

ecological release

Answer 31

when competition is reduced, it results in ecological release. this is an opportunity for a species to expand its use of resources within habitats that now have less competition

Question 32

gradualistic model of evolution

Answer 32

the gradual evolution of new species is the basis of the gradualistic model of evolution

Question 33

punctuated equilibrium model

Answer 33

used to explain the fluctuating pace of evolution. this model says that the assembly of species in the fossil record can be explained by periods of equilibrium, or stasis, punctutated (interrupted) by periods of rapid, arubpt speciation, or change