Chapter 5: Process 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; includes 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, meaning “same,” and plasy, meaning “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 base solely on analysis of certain types of homologous characters (those considered to be derived characters).

Question 9

ancestral

Answer 9

Referring to characters inherited by a group of organisms from a remote ancestor and thus not diagnostic of groups (lineages) that diverged after the character first appeared; also called primitive.

Question 10

clade

Answer 10

A group of organisms sharing a common ancestor. The 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

Relating 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. It contains a time component and implies ancestor-descendant relationships.

Question 14

cladogram

Answer 14

A chart showing evolutionary relationships as determined by cladistic analysis. It’s based solely on interpretations of shared derived characters. It contains no time component and does not imply ancestor-descendant relationships.

Question 15

biological species concept

Answer 15

A depiction of species as groups 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 evolves from an earlier species. Speciation is the most basic process in macroevolution.

Question 17

sexual dimorphism

Answer 17

Differences in physical characteristics between males and females of the same species. For example, humans are slightly sexual dimorphic for body size, with males being taller, on average , than females of the same population. Sexual dimorphism is 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

Answer 21

(pl., genera) A group of closely related species.

Question 22

ecological niche

Answer 22

The position of a species within its physical and biological environments. A species’ ecological niche is defined by such components as diet, terrain, vegetation, type of predators, relationship with other species, and activity patterns, and each niche is unique to a given species. Together, ecological niches 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. Mineralization 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 a 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 paleoanthropologist.

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 the Cenozoic era, epochs include the Paleocene, Eocene, Oligocene, Miocene, and the Pliocene (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, placentals 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; characteristics of mammals, whose teeth consist of incisors, canines, pre-molars, and molars.

Question 31

endothermic

Answer 31

(endo, meaning “within” or “internal) 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.