Apbiotest: Evolution

Front 1

Allopatric speciation

Back 1

Speciation that occurs when the initial block to gene flow is a
geographical barrier that physically isolates the population (i.e. mountain ranges, movement of
glaciers, formation of land bridges, subsidence of large lakes).

Front 2

Adaptive radiation

Back 2

The evolution of many diversely adapted species from a common
ancestor.

i.e. darwin's finches

Front 3

Sympatric speciation

Back 3

chromosomal changes in plants, non random mating alter gene flow. genetically isolated even tho their ranges over lap

Formation of new species within the range of parent populations.

Reproductive isolation evolves without geographical isolation.
• This can occur quickly (in one generation) if a genetic change results in a
reproductive barrier between the mutants and the parent population.

Front 4

Biogeography

Back 4

The geographical distribution of species

Front 5

Cline

Back 5

change in a trait due to geological factor

One type of geographical variation that is a graded change in some trait
along a geographic transect. (For example, the average body size of many North American mammal
species gradually increases with increasing latitude. It is presumed that the
reduced surface area to volume ratio associated with larger size helps
animals in cold environments conserve body heat.)

Front 6

population genetics

Back 6

Emphasized genetic variation within populations and recognized the
importance of quantitative characters

Was an important turning point for evolutionary theory, because it reconciled
Mendelian genetics with Darwinian evolution

Front 7

Gene pool

Back 7

The total aggregate of genes in a population at any one time

Front 8

geographical variation

Back 8

differences in genetic structure btwn populations

affected by nat. selec. and genetic drift

Front 9

polymorphism

Back 9

when two or more of a discrete trait are represented in a population