38 terms

Friedland APES Chapter 5


Terms in this set (...)

ecosystem diversity
the measure of the variety of ecosystems within a region
species diversity
the measure of the variety of species within an ecosystem
genetic diversity
the measure of the variety of genes within a species
species richness
the number of species in a given area
species evenness
tells us whether a particular ecosystem is numerically dominated by one species or whether all of its species have similar abundances
the branching patterns of evolutionary relationships
a change in the genetic composition of a population over time
the evolution below the species level, such as the evolution of different varieties of apples or potatoes
the process in which genetic changes give rise to a new species, genera, family, class, or phyla
are physical locations on chromosomes within each cell of an organism; determines the range of possible traits that it can pass down to its offspring
the complete set of genes in an individual
an occasional mistake in the copying process of DNA produces a random change in the genetic code
occurs as chromosomes are duplicated during reproductive cell division and a piece of one chromosome breaks off and attaches to another chromosome
the actual set of traits expressed in that individual
artificial selection
when humans determine which individuals breed, typically with a preconceived set of traits in mind
natural selection
the environment determines which individuals survive and reproduce
an individual's ability to survive and reproduce
traits that improve an individual's fitness
genetic drift
a change in the genetic composition of a population over time as a result of random mating
bottleneck effect
a reduction in the genetic diversity of a population caused by a reduction in its size
founder effect
a change in a population descended from a small number of colonizing individuals
geographic isolation
when a subset of individuals from a larger population may colonize a new area of habitat that is physically separated from that of the rest of the population
reproductive isolation
when the geographically separated population becomes so different that even if the physical barrier were removed, they could no longer interbreed and produce viable offspring
allopatric speciation
a process of speciation that requires geographic isolation
sympatric speciation
the evolution of one species into two species in the absence of geographic isolation
genetic engineering
techniques in which scientists can now copy genes form a species with some desirable trait and insert these genes into other species
genetically modified organisms
organisms that have had their genetic makeup modified by genetic engineering
range of tolerance
limits to the abiotic conditions they can tolerate
fundamental niche
The full potential range of the physical, chemical, and biological factors a species can use if there is no competition from other species.
realized niche
the range of abiotic and biotic conditions under which a species actually lives
species distribution
the areas of the world in which the species lives
niche generalists
organisms that can live in a variety of habitats or feed on a variety of species
niche specialists
organisms that are specialized to lie in a specific habitat of feed on a small group of species
the remains of organisms that have been preserved in rock
mass extinction
events in which large number of species when extinct over relatively short periods of time
sixth mass extinction
scientists have predicted/identified a new mass extinction is underway and an estimated 2-25 percent of species will go extinct; it is caused by humans
endemic species
A species that is found in its originating location and is generally restricted to that geographic area.
biodiversity hot spot
A relatively small area with an exceptional concentration of endemic species and a large number of endangered and threatened species

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