Mechanisms for Evolutionary Change Flashcards
A change to a
population’s gene pool by
chance.
Process by which allele
frequencies fluctuate
unpredictably from one
generation to the next in a
small population.
Genetic Drift
Two types of genetic drift
founder effect
bottleneck effect
Change in the genetic frequency
due to the movement of fertile
individuals and their gametes in
and out of the population.
Gene flow
mechanism where organisms
whose traits are well-suited to
the environment tend to
survive and produce more
offspring than other
organisms whose traits are
not suited to the environment,
is the only mechanism which
results in adaptation.
Natural Selection
What are the 3 modes of natural selection
Directional
Stabilizing
disruptive
the link between the mechanisms of
evolutionary change and the appearance of new
species and extinction of pre-existing groups of
organisms.
“process by which one species splits into two or
more species.”
Speciation
what are the 4 species concept
Biological species concept
Morphological species concept
Ecological species concept
Phylogenetic species concept
TWO Mechanisms of Speciation
Allopatric speciation
Sympatric speciation
mutations resulting in
some members of a population to have extra sets of chromosomes
Polyploidy
the genes of certain members of a population enable them to reach areas, habitats, or sources of food which are not
accessible to other members of a population.
Temporal isolation
what are the pre-zygotic Isolating mechanisms
ecological
temporal
behavioral
mechanical
what are the post-zygotic Isolating mechanisms
hybrid inviability
hybrid infertility
hybrid breakdown
can be defined as groups of organisms which interbreed at a specific place and at a
specific time.
species
The first single-celled organisms
existed about 3.5 billion years
ago.
Stromatolites
