Adaptations - Answers A feature of an organism created by the process of natural selection
Natural Selection - Answers The process that produces adaptation
Morphology - Answers The form and structure of an organism; also a field of study that focuses on the
form and structure of organisms
Equilibrium - Answers A steady state in which the composition of the population does not change
Stabilizing Selection - Answers Selection pressures that favor average phenotypes.
Traits - Answers A characteristic of an organism
Characters - Answers A trait or attribute of the phenotype of an organism
Species - Answers A group of organisms classified together at the lowest level of the taxonomic
hierarchy
Fecundity - Answers The biological capacity to reproduce.
Continuous Variation - Answers Phenotypic variation in which there is a continuum of types.
Discontinuous Variation - Answers Phenotypic variation in which there is a discrete number of
phenotypes with no intermediate types
Convergence - Answers The evolution of similar adaptations in unrelated species. The evolution of
camera-type eyes in both vertebrates and mollusks is an example of this
Placental Mammals - Answers A mammal that gives birth to live young that developed for a period of
time in the uterus and were nourished by blood delivered to a placenta.
Marsupials - Answers A mammal that gives birth to live young that continue their development in a
pouch equipped with mammary glands. Examples include kangaroos and opossums.
Blending Inheritance - Answers A model of inheritance, widely accepted during the nineteenth century,
in which the hereditary material of the mother and father was thought to combine irreversibly in the
offspring.
Microevolution - Answers Evolution of populations within a species
Macroevolution - Answers Evolution of new species, families, and higher taxa
Testes - Answers The male organs responsible for sperm production
Biological Species Concept - Answers The concept that species are defined as a group of organisms that
cannot interbreed in nature
, Reproductive Isolation - Answers A relationship between two populations in which there is no gene flow
between them
Gene Flow - Answers The movement of genes from one population to another, or from one part of a
population to another, as the result of interbreeding
Ecological Species Concept - Answers The concept that natural selection plays an important role in
maintaining the differences between species, and that the absence of interbreeding between two
populations is not a necessary condition for defining them as a separate species
Allopatric Speciation - Answers Speciation that occurs when two or more populations of a single species
are geogaphically isolated from each other and then diverge to form two or more new species
Character Displacement - Answers The result of competition between two species that causes the
members of different species to become morphologically or behaviorally more different from each other
Reinforcement - Answers The process in which selection acts against the likelihood of hybrids occurring
between members of two phenotypically distinctive populations, leading to the evolution of
mechanisms that prevent interbreeding
Parapatric Speciation - Answers A two step process of speciation in which selection causes the
differentiation of geographically separate, partially isolated populations of a species and subsequently
the populations become reproductively isolated as a result of reinforcement
Hybrid Zone - Answers A geographic region where two or more populations of the same species or two
different species overlap and interbreed.
Sympatric Speciation - Answers A hypothesis that speciation can result from selective pressures favoring
different phenotypes within a population, without positing geographic isolation as a factor
Niche - Answers The way of life, or "trade", of a particular species- what foods it eats and how the food
is acquired
Adaptive Radiation - Answers The process in which a single lineage diversifies into a number of species,
each characterized by distinctive adaptations
Phylogeny - Answers The evolutionary relationships among a group of species, usually diagrammed as a
"family tree"
Hominoids - Answers Any member of the superfamily Hominoidea which includes humans, all the living
apes, and numerous extinct apelike and human like species from Miocene, Pliocene, and Pleistocene
epochs
Taxonomy - Answers A branch of biology that is concerned with the use of phylogenies for naming and
classifying organisms
Quadrupedal - Answers Describing locomotion in which the animal moves on all four limbs