Download Chapter 7, Processes of Macroevolution

Chapter 7, Processes of Macroevolution:
Mammalian/Primate Evolutionary History
Key Terms

Classification
In biology, the ordering of organisms into
categories, such as orders, families, and
genera, to show evolutionary relationships.

Metazoa
Multicellular animals; a major division of the
animal kingdom.

Chordata
The phylum of the animal kingdom that
includes vertebrates.

Vertebrates
Animals with bony backbones; includes fishes,
amphibians, reptiles, birds, and mammals.

Homologies
Similarities between organisms based on
descent from a common ancestor.

Analogies
Similarities between organisms based strictly
on common function,with no assumed
common evolutionary descent.

Homoplasy
The separate evolutionary development of
similar characteristics in different groups of
organisms.

Evolutionary systematics
A traditional approach to classification (and
evolutionary interpretation) in which
presumed ancestors and descendants are
traced in time by analysis of homologous
characters.

Cladistics
An approach to classification that seeks to
make rigorous evolutionary interpretations
based solely on analysis of certain types of
homologous characters (those considered
derived characters).

Derived
Referring to characters that are modified from
the ancestral condition and thus are
diagnostic of particular evolutionary lineages.

Ancestral
Referring to characters inherited by a group
of organisms from a remote ancestor and
thus not diagnostic of groups (lineages)
branching subsequent to the time the
character first appeared.

Shared derived
Relating to specific character states shared in
common between two forms and considered
the most useful for making evolutionary
interpretations.

Phylogenetic tree
A chart showing evolutionary relationships as
determined by phylogenetic systematics. It
contains a time component and implies
ancestor-descendant relationships.

Cladogram
A chart showing evolutionary relationships as
determined by cladistic analysis. It is based
solely on interpretation of shared derived
characters. No time component is indicated,
and ancestor descendant relationships are
not implied.

Biological species concept
A depiction of species as groups of
individuals capable of fertile interbreeding but
reproductively isolated from other such
groups.

Speciation
The process where a new species evolves
from a prior species. Speciation is the most
basic process in macroevolution.

Intraspecific
Within species; refers to variation seen within
the same species.

Interspecific
Between species; refers to variation beyond
that seen within the same species to include
additional aspects seen between two different
species.

Paleospecies
Species defined from fossil evidence, often
covering a long time span.

Genus
A group of closely related species.

Geological time scale
The organization of earth history into eras,
periods, and epochs; commonly used by
geologists and paleoanthropologists.

Continental drift
The movement of continents on sliding plates
of the earth’s surface. As a result, the
positions of large landmasses have shifted
dramatically during the earth’s history.

Ecological niches
The positions of species within their physical
and biological environments, together making
up the ecosystem. A species’ ecological niche
is defined by such components as diet,
terrain, vegetation, type of predators,
relationships with other species, and activity
patterns, and each niche is unique to a given
species.

Epochs
Categories of the geological time scale;
subdivisions of periods. In the Cenozoic,
epochs include the Paleocene, Eocene,
Oligocene, Miocene, and Pliocene (from the
Tertiary) and the Pleistocene and Holocene
(from the Quaternary).

Adaptive radiation
The relatively rapid expansion and
diversification of life forms into new ecological
niches.

Heterodont
Having different kinds of teeth; characteristic
of mammals, whose teeth consist of incisors,
canines, premolars, and molars.

Endothermic
Able to maintain internal body temperature
through the production of energy by means of
metabolic processes within cells;
characteristic of mammals, birds, and
perhaps some dinosaurs.

Large-bodied hominoids
Those hominoids including the great apes
(orangutans, chimpanzees, gorillas) and
hominids, as well as all ancestral forms back
to the time of divergence from small-bodied
hominoids (i.e., the gibbon lineage).

Hominids
Colloquial term for members of the family
Hominidae, which includes all bipedal
hominoids back to the divergence from
African great apes.

Punctuated equilibrium
The concept that evolutionary change
proceeds through long periods of stasis
punctuated by rapid periods of change.