lect 9 Flashcards
a population ecologically
A group of individuals of the same species living within
a restricted geographical area any 2 can interbreed
a population Genetically
A group of individuals who share a common gene pool
and have the potential to interbreed.
population genetics is the study of..and
application of Mendel’s laws and other principles to entire
populations
changes in gene
frequencies
examining a population
phenotype variation/genotype variation
population genetics in culture vs science
culture : composition and evolutionary forces
science: inheritance and prevalence of genes using stats
Population genetics examines
adaptation, speciation, population subdivision,
and population structure
processes of evolution
Natural selection/gene flow/mutations
Phenotypic differences can be..
quantitative or qualitative
some genotypes can have
different phenotypes due to environment impact
natural populations are…
the more closely related the
phenotypically diverse
less variability
low variability disadvantage
extinction when environmental conditions change
Population genetics deals with …especially
where it is due to differences in..of
individuals.
phenotypic diversity,
the genotypic composition
allele freq
evolution
rate of allele occuring at a particular locus, high is common allele , low is rare allele
change in allele freq
Forces Affecting Change in Allele Frequency
1.Natural Selection
2. Mutation:
3. Gene Flow:
4. Genetic Drift:
5. Genetic Bottleneck:
6. Sexual Selection:
Natural Selection:
2. Mutation:
3. Gene Flow:
favors alleles offering fitness advantages.
introduces new alleles through “mistakes” in DNA copying.
introduces new alleles through dispersal (immigration).
Genetic Drift:
5. Genetic Bottleneck: .
6. Sexual Selection:
random change in allele frequency (e.g., demographic
isolation).
decreased diversity through culling/decline (e.g., flood)
favoring more “attractive” alleles (e.g., body shape).
Genes include
transcribed section and a regulatory
element
how mendel defined his laws
by observing the
segregation of variants in the progeny of crosses and observing the genes being expressed
dominant and codominant
recessive allele not
expressed in an heterozygous individual.
intermediate in the heterozygote
‘GENE’ is
genotype is
physical entity that is
transmitted from parents to offspring
sum of all genes
impossible for two individuals in a
population to have the same genotype at all loci except…
identical twins
molecular technologies reveal
polymorphisms
What is Polymorphism
co-existence of two or more alternative phenotypes caused by alternative alleles of one gene.
polymorphism molecularly
co-existence of alternative banding
patterns or DNA variants
phenotypic trait is said to be polymorphic if,,,
more than one form of the
gene or trait exists in a population.
local interbreeding units are usually called …..
local populations,
sub-populations or simply populations.
members of a species are..
Subdivision of populations are often due to ……
population size is not ..
unevenly distributed
accidents
infinitely large nor constant
