DAT Evolution Flashcards
changes in
allele frequencies in populations,
species or groups over time
evolution
what is evolution driven by
natural seleection
Changes in allele
frequencies that occur within a
population
microevolution
Pattern of
changes in groups of related
species over broad periods of
geologic time
macroevolution
Natural selection (“survival of the fittest”)… what theory of evolution
Darwin-Wallace
Body features acquired during one’s
lifetime (due to use/disuse) can be passed
down to offspring (FALSE)…. what theory of evolution
Lamarck
Changes in allele
frequencies that
lead to increased
fitness (“survival
of the fittest”)
natural selection
Ability
of an offspring
to survive and
produce fertile
offspring
fitness
Allele frequencies remain constant from generation
to generation when there is…
no evolution occuring
can be used to determine
allele frequencies in a population that is in genetic
equilibrium
Hardy-Weinberg equation
The 5 requirements of genetic equilibrium are:
- No mutations
- No natural selection
- No gene flow
- Large population
- Random mating
Random increase or
decrease of an allele
genetic drift
types of genetic drift
bottleneck effect, founders effect
Addition or removal of alleles
from a population when individuals
enter/leave
gene flow
Hardy Weinberg Equation is what
p2 + 2pq + q2 = 1
frequency of homozygous dominant (HW)
p2
frequency of heterozygous (HW)
2pq
frequency of homozygous recessive
q2
other eqn in HW
p + q = 1
frequency of dominant allele
p
freq of recessive allele
q
Maintenance of different
phenotypes in a population
balanced polymorphism
Heterozygote is more
advantageous than either homozygous conditions
Heterozygote advantage:
In heterozygous conditions, recessive allele
is stored for later gen.
diploidy
Sources of Genetic Variation
- Mutation
- Sexual Reproduction
- Balanced Polymorphism:
- diploidy
Body
parts that resemble one another
between different species that
descended from a common
ancestor (e.g., bat vs bird
forelimbs)
homologous structures
Body
parts that resemble one another
between different species that
evolved independently (e.g., bat
vs bee wings)
analogous structures
Formation of two or
more species that descend from a common
ancestry and become increasingly different
over time (results of speciation)
divergent evolution
Two unrelated
species, independently evolving similar traits
as a result of having to adapt to similar
environments (analogous traits)
convergent evolution
two related species
develop similar adaptations or traits after
their divergence from a common ancestor
parallel evolution
Two or more species having a
close ecological relationship evolve together
in response to new adaptations that appear
in another species (predator/prey)
coevolution
Formation of a new species
speciation
(begins when gene flow ceases between two
sections of a population)
speciation
Group of individuals capable of interbreeding
species
Occurs when
population is divided
by a geographic barrier
allopatric speciation
Occurs without the
presence of a geographic
barrier (polyploidy,
habitat differentiation)
sympatric speciation
