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evolution (Hardy-Weinberg (CRITERIA (random mating, no natural selection,…
evolution
Hardy-Weinberg
p=one allele (same loci)
q=other allele (same loci)
Allele frequency
genotype frequency
CRITERIA
random mating
no natural selection
no mutations
large population
no gene flow
evolution note occurring
Genetic Drift
Bottleneck Effect
change in environment reduces po[lation size
ex: fire or flood
less genetic variation
human actions can cause bottlenecks
Founder Effect
dew individuals isolated
from larger population
establish new population
chance events
cause allele frequencies to fluctuate
Speciation
reproductive barriers
postzygotic
Hybrid breakdown (other generations sterile)
Reduced Hybrid fertility
Reduced hybrid viability (survival)
prezygotic
gametic isolation
mechanical isolation
Habitat isolation
behavioral isolation
Temporal isolation
Sympatric
Same country
population divided
geographically isolated subpopulations
Allopatric
Other country
Polyploidy
cell division
accidents= extra chromosomes
Autopolyploid
failure cell division
extra chromosome
example
2n diploid makes 4n tetraploid
self pollinates or mates other tetraploid
4n+2n=3n sterile offspring
reproductive isolation
Allopolyploid
hybrid
asexual propagation
eventual fertile in mating
Concepts
Biological Species Concept
ecological species concept
morphological species concept
HISTORY
Archaean eon
Oxygen revolution
photosynthetic prokaryotes
Proterzoic eon
first eukaryotes
endosymbiosis
mitochondrion & plastifd
serial endosymbiosis
before plastids
mitochondrion evolved first
Hadean eon
origin of earth
Phanerozoic eon
paleozoic era
Cambrian Explosion
increase predators
hard bodied organisms'
PERMIAN EXTINCTION
extreme volcanism
chain reaction
catastrophic events
took 96% marine animals
mesozoic era
CRETACEOUS EXTINCTION
meteorite hit earth
hot cloud an debris
took more than 50% marine animals
took all dinosaurs
cenozoic era
Gene Flow
transfer of genes in/out of population
due to movement of fertile individuals
emigration and immigration
Natural Selection
Balancing Selection
Heterozygote advantage
heterozygote has greater fitness
fitness of genotype
natural selction maintains 2 or more alleles at locus
example:
sickle cell
heterozygote protected against malaria
maintains 2+ phenotypic forms
in a population
Frequency Dependent Selection
fitness of phenotype
depends on how common
in population
example:
right-mouthed fish
left-mouthed fish
sexual selection
intersexual selection
mate choice
intrasexual selection
competition within a sex for the mate of opposite sex
