Chapter 24

Question 1

extant

Answer 1

a species that is living today

Question 2

extinct

Answer 2

said of a species that has died out

Question 3

transitional features

Answer 3

a trait that is intermediate between a condition observed in ancestral species and the condition observed in more derived species

Question 4

vestigial traits

Answer 4

any rudimentary structure of unknown or minimal function that is homologous to functioning structures in other species. Vestigial structures are said to reflect evolutionary history

Question 5

phylogeny

Answer 5

the evolutionary history of a group of organisms

Question 6

phylogenetic tree

Answer 6

a diagram that depicts the evolutionary history of a group of species and the relationships among them

Question 7

homology

Answer 7

similarity among organisms of different species due to their inheritance from a common ancestor. Features that exhibit such similarity are said to be homologous.

Question 8

genetic homologies

Answer 8

similarities in DNA sequences or amino acid sequences that are due to inheritance from a common ancestor

Question 9

developmental homologies

Answer 9

a similarity in embryonic form or in the fate of embryonic tissues, that is due to inheritance from a common ancestor.

Question 10

morphology

Answer 10

the shape and appearance of an organism’s body and its component parts

Question 11

structural homologies

Answer 11

similarities in organismal structures that are due to inheritance from a common ancestor.

Question 12

vertebrates

Answer 12

one of the three major chordate lineages, compromising animals with a dorsal column of cartilaginous or bony structures and a skull enclosing the brain. Includes fish, amphibians, mammals, reptiles, and birds.

Question 13

natural experiment

Answer 13

a situation in which groups to be compared are created by an unplanned, natural change in conditions rather than by manipulation of conditions by researchers.

Question 14

cetaceans

Answer 14

a marine mammal including a dolphin, porpoise and whale

Question 15

internal consistency

Answer 15

typically a measure based on the correlations between different items on the same test. It measures whether several items that propose to measure the same general construct produce similar scores

Question 16

historical constraint

Answer 16

the restriction of adaptations because traits have evolved from previously existing traits

Question 17

selfish allele

Answer 17

the favorable alleles that survive to reproduce

Question 18

acclimation

Answer 18

the biological changes an animal or plant goes through in response to a change in their environment

Question 19

law of succession

Answer 19

extinct species were succeeded by similar looking living species

Question 20

genetic correlation

Answer 20

occurs when selection favoring alleles for one trait causes a correlated but suboptimal change in an allele for another trait

Question 21

genetic constraint

Answer 21

a variable that causes the population to evolve however the best, optimal state is not reached

Question 22

trade-off

Answer 22

a compromise between two traits in terms of how those traits are adapted for the environment