chapter 5: processes of macroevolution

Question 1

classification

Answer 1

in biology, the ordering of organisms into categories, such as orders, families, and genera, to show evolutionary relationships

Question 2

chordata

Answer 2

the phylum of the animal kingdom that includes vertebrates

Question 3

vertebrates

Answer 3

animals with segmented, bony spinal columns; include fishes, amphibians, reptiles (including birds), and mammals

Question 4

homologies

Answer 4

similarities between organisms based on descent from a common ancestor

Question 5

analogies

Answer 5

similarities between organisms based strictly on common function, with no assumed common evolutionary descent

Question 6

homoplasy

Answer 6

homo = same, plasy = growth; the separate evolutionary development of similar characteristics in different groups of organisms

Question 7

evolutionary systematics

Answer 7

a traditional approach to classification (and evolutionary interpretation) in which presumed ancestors and descendants are traced in time by analysis of homologous characters

Question 8

cladistics

Answer 8

an approach to classification that attempts to make rigorous evolutionary interpretations based solely on analysis of certain types of homologous characters (those considered to be derived characters)

Question 9

ancestral

Answer 9

characteristics inherited by a group of organisms from a remote ancestor and thus not diagnostic of groups (lineages) that diverged after the character first appeared; aka primitive

Question 10

clade

Answer 10

a group of organisms sharing a common ancestor; group includes the common ancestor and all descendants

Question 11

derived (modified)

Answer 11

referring to characters that are modified from the ancestral condition and thus diagnostic of particular evolutionary lineages

Question 12

shared derived

Answer 12

relations to specific character traits shared in common between two life-forms and considered the most useful type of characteristic for making evolutionary interpretations

Question 13

phylogenetic tree

Answer 13

a chart showing evolutionary relationships as determined by evolutionary systematics; contains a time component and implies ancestor-descendant relationships

Question 14

cladogram

Answer 14

a chart showing evolutionary relationships as determined by cladistic analysis; based solely on interpretation of shared derived characters; contains no time component and does not imply ancestor-descendant relationships

Question 15

biological species concept

Answer 15

a depiction of a species as a group of individuals as a group of individuals capable of fertile interbreeding but reproductively isolated from other such groups

Question 16

speciation

Answer 16

the process by which a new species evolved from an earlier species; the most basic process in macroevolution

Question 17

sexual dimorphism

Answer 17

differences in physical characteristics between males and females of the same species; ex: humans are slightly sexually dimorphic for body size, with males being taller, on average, than females of the same population; very pronounced in many species, such as gorillas

Question 18

intraspecific

Answer 18

within species; refers to variation seen within the same species

Question 19

interspecific

Answer 19

between species; refers to variation beyond that seen within the same species to include additional aspects seen between two different species

Question 20

paleospecies

Answer 20

species defined from fossil evidence, often covering a long time span

Question 21

genus, genera

Answer 21

a group of closely related species

Question 22

ecological niche

Answer 22

the position of a species within its physical and biological environments; defined by such components as diet, terrain, vegetation, type of predators, relationships with other species, and activity patterns, and each is unique to a given species; together, they all make up an ecosystem

Question 23

fossils

Answer 23

traces or remnants of organisms found in geological beds on the earth’s surface

Question 24

mineralization

Answer 24

the process in which parts of animals (or some plants) become transformed into stone-like structures; usually occurs very slowly as water carrying minerals, such as silica or iron, seeps into the tiny spaces within a bone; in some cases, the original minerals within the bone or tooth can be completely replaced, molecule by molecule, with other minerals

Question 25

taphonomy

Answer 25

the study of how bones and other materials come to be buried in the earth and preserved as fossils

Question 26

geological time scale

Answer 26

the organization of earth history into eras, periods, and epochs; commonly used by geologists and paleoanthropologists

Question 27

continental drift

Answer 27

the movement of continents on sliding plates of the earth’s surface; as a result, the positions of large landmasses have shifted drastically during the earth’s history

Question 28

epochs

Answer 28

categories of the geological time scale, subdivisions of periods; in cenozoic era, they include paleocene, eocene, oligocene, miocene, and piliocene (from the tertiary period) and the pleistocene and holocene (from the quaternary period)

Question 29

placental

Answer 29

a type (subclass) of mammal; during the cenozoic, they became the most widespread and numerous mammals and today, are represented by upward of 20 orders, including the primates

Question 30

heterodont

Answer 30

having different kinds of teeth; characteristic of mammals, whose teeth consists of incisors, canines, premolars, and molars

Question 31

endothermic

Answer 31

endo = within or internal, thermic = heat; able to maintain internal body temperature by producing energy through metabolic processes within cells; characteristic of mammals, birds, and perhaps some dinosaurs

Question 32

adaptive radiation

Answer 32

the relatively rapid expansion and diversification of life-forms into new ecological niches