extrachromosomal inheritance tapos population genetics Flashcards
Members of a species
can interbreed &
produce fertile
offspring
Gene Pool
all of the
alleles of all individuals
in a population
Gene pool
A group of the
same species living
in an area
Populations
Formation of new
species and Requires very long periods of time
Speciation
study of genetic
variation within a
population
Population genetics
Emphasis on
quantitative
characters
Combines Darwinian
selection and
Mendelian inheritance
comprehensive
theory of evolution
(Modern Synthesis
Theory)
1940s
are responsible for
the inheritance of characteristics
GENES
not
individuals, evolve due to natural selection
& genetic drift
POPULATIONS
usually is due
to the gradual accumulation of small genetic
changes
SPECIATION
Used to describe a non-evolving population.
Hardy-Weinberg Principle
meiosis and random fertilization have no effect on the overall gene pool.
Shuffling of alleles
are NOT
expected to actually be in Hardy Weinberg equilibrium.
Natural populations
from Hardy-Weinberg
equilibrium usually results in
evolution
Deviation
5 Assumptions of the H-W Principle
Large population size
No migration
No net mutations
Random mating
No natural selection
small populations have fluctuations in allele
frequencies
Large population size
immigrants can change the frequency of an
allele by bringing in new alleles to a
population.
No migration
if alleles change from one to another, this
will change the frequency of those alleles
No net mutations
if certain traits are more desirable, then individuals with those traits will be
selected and this will not allow for random
mixing of alleles.
Random mating
if some individuals survive and reproduce
at a higher rate than others, then their
offspring will carry those genes and the
frequency will change for the next
generation.
No natural selection
The gene pool of a NON-EVOLVING population remains BLANK over multiple
generations
CONSTANT
the change in the gene pool of a small
population due to chance
Genetic Drift
success in reproduction based on heritable
traits results in selected alleles being passed to
relatively more offspring
Natural Selection
is genetic exchange due to the migration of
fertile individuals or gametes between
populations
Gene Flow
a change in an organism’s DNA
Mutations can be transmitted in gametes to
offspring
Mutation
Mates are chosen on the basis of the best
traits
Non-random mating
Causes of Microevolution 5
Genetic Drift
Natural Selection
Gene Flow
Mutation
Non-random mating
a drastic reduction in population (volcanoes,
earthquakes, landslides …)
Bottleneck Effect
occurs when a new colony is started by a few
members of the original population
Founder Effect
have little genetic variation in
their gene pool
Cheetahs
Modes of Natural Selection 3
Directional Selection
Disruptive selection
Stabilizing Selection
Favors individuals at one end of the phenotypic
range
Directional Selection
Favors extreme over intermediate phenotypes
Disruptive selection
Favors intermediate over extreme phenotypes
Stabilizing Selection
often result in
little or no benefit to an organism, or are often
harmful
Mutations
source of most genetic differences between
individuals in a population
Genetic Recombination
Often occurs between parasite & host and
flowers & their pollinators
Co-evolution
also known as cytoplasmic or extranuclear inheritance, also refers to the inheritance of traits that are not controlled by chromosome genes. Discovered by Boris Ephrussi.
Extrachromosomal Inheritance
Possess their own DNA, known as Chloroplast DNA
Chloroplast Inheritance
Chloroplast Inheritance discovered by
Carl Correns and Erwin Baur in 1909
Is the main form of extrachromosomal inheritance in animals
Mitochondrial Inheritance
Refers to a mode of inheritance where genetic material or traits are inherited from a single parent, either the mother or the father
Uniparental Inheritance
Is a less common form of extrachromosomal inheritance where genetic material from both parents contributes to the traits encoded by the extrachromosomal organelles
Biparental Inheritance
Is a mode of extrachromosomal inheritance that involves the random distribution of cytoplasmic elements during cell division in asexual reproduction
Vegetative Segregation
