the process of evolution how it works and how we see it
TRANSCRIPT
The Process of The Process of EvolutionEvolution
How it Works and How How it Works and How we See Itwe See It
Topic OutlineTopic Outline
Evolution in a Genetic ContextEvolution in a Genetic Context - Microevolution- Microevolution
Hardy-WeinbergHardy-Weinberg Causes of MicroevolutionCauses of Microevolution Natural SelectionNatural Selection
Types of SelectionTypes of Selection Maintenance of VariationsMaintenance of Variations SpeciationSpeciation
Modes of SpeciationModes of Speciation
Background VocabularyBackground Vocabulary GeneGene AlleleAllele Phenotype vs GenotypePhenotype vs Genotype HomozygousHomozygous HeterozygousHeterozygous Gene poolGene pool MicroevolutionMicroevolution Polygenic (Quantitative) vs Monogenic Polygenic (Quantitative) vs Monogenic
TraitsTraits
The Hardy-Weinberg ModelThe Hardy-Weinberg Model
pp22 + + 2pq2pq + + qq22
And And
pp++q=1q=1
What Does it Mean?What Does it Mean?
p=Frequency of Dominant allelep=Frequency of Dominant allele q=Frequency of recessive alleleq=Frequency of recessive allele pp22=frequency of Homozygous =frequency of Homozygous
dominant individualsdominant individuals qq22=frequency of homozygous =frequency of homozygous
recessive indvidualsrecessive indviduals 2pq=frequency of heterozygotes2pq=frequency of heterozygotes
So What?So What?
The Hardy-Weinberg principle states The Hardy-Weinberg principle states an equilibrium of allele frequencies in an equilibrium of allele frequencies in a gene pool of a sexually reproducing a gene pool of a sexually reproducing population, population, pp22 + + 2pq2pq + + qq22, won’t , won’t change as long as certain conditions change as long as certain conditions are met. What are these conditions?are met. What are these conditions?
Example: Industrial Example: Industrial MelanismMelanism
Causes of MicroevolutionCauses of Microevolution
Genetic Mutations Genetic Mutations Gene FlowGene Flow Nonrandom MatingNonrandom Mating Genetic DriftGenetic Drift Natural SelectionNatural Selection
MUTATIONSMUTATIONS
Gene mutations -- -- the only source Gene mutations -- -- the only source of new allelesof new alleles
Chromosomal mutations -- -- Chromosomal mutations -- -- alterations in the number, alterations in the number, composition, or the arrangement of composition, or the arrangement of gene’s on a chromosomegene’s on a chromosome
Chromosomal mutationsChromosomal mutations
DeletionDeletion
TranslocationTranslocation
DuplicationDuplication
InversionInversion
Gene FlowGene FlowPhysical Movement of AllelesPhysical Movement of Alleles
Nonrandom MatingNonrandom Mating
Assortative mating Assortative mating
Sexual selectionSexual selection
Genetic DriftGenetic Drift
Bottleneck EffectBottleneck Effect
Founder EffectFounder Effect
Bottleneck EffectBottleneck Effect
Founder EffectFounder Effect
Founder Effect 2Founder Effect 2
Natural SelectionNatural Selection
Types of SelectionTypes of Selection
Directional SelectionDirectional Selection
Stabilizing SelectionStabilizing Selection
Disruptive SelectionDisruptive Selection
Directional Directional SelectionSelection
Stabilizing Stabilizing SelectionSelection
Disruptive Disruptive SelectionSelection
Maintenance of VariationsMaintenance of Variations
Are there any advantages to variation Are there any advantages to variation in a population?in a population?
Sickle Cell DistributionSickle Cell Distribution
SpeciationSpeciation
Species DefinitionSpecies DefinitionMorphologicalMorphologicalBiologicalBiological
Reproductive IsolationReproductive IsolationPhylogeneticPhylogenetic
SpeciesSpecies A group of interbreeding A group of interbreeding
populations that share a gene populations that share a gene pool and are pool and are reproductively reproductively isolatedisolated from other species. from other species.
Subpopulations can exchange Subpopulations can exchange genes. Different species can’t.genes. Different species can’t.
Reproductive Isolating Reproductive Isolating MechanismsMechanisms
Prezygotic Isolating Prezygotic Isolating MechanismsMechanisms
Postzygotic Isolating Postzygotic Isolating MechanismsMechanisms
Modes of SpeciationModes of Speciation
Allopatric Speciation-Allopatric Speciation-spatial separationspatial separation
Sympatric Speciation- no Sympatric Speciation- no spatial separationspatial separation
SYMPATRIC SPECIATION --EXSYMPATRIC SPECIATION --EX
SPECIES A: 2N=14,SPECIES A: 2N=14,
N = 7N = 7
DUPLICATIONDUPLICATION
SPECIES A’: 2N=28SPECIES A’: 2N=28
N = 14N = 14
SPECIES A X SPECIES B 2N=21SPECIES A X SPECIES B 2N=21
N=?N=?
Adaptive RadiationAdaptive Radiation
ReviewReview Evolution in a Genetic ContextEvolution in a Genetic Context
- Microevolution- Microevolution Hardy-WeinbergHardy-Weinberg Causes of MicroevolutionCauses of Microevolution Natural SelectionNatural Selection
Types of SelectionTypes of Selection Maintenance of VariationsMaintenance of Variations SpeciationSpeciation
Modes of SpeciationModes of Speciation
