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Hardy Weinberg Equation, Exam 5 Material - Coggle Diagram

- - - - group of individuals of the same species that occupy the same region and can interbreed with each other
  - - - alleles of one type / total # alleles
        
        EX:
        
        Allele Frequency
        
        = 3 / 6
        
        0.5
        
        Genotype Frequency
        
        WW = 1/3
        
        0.33
        
        Ww = 1/3
        
        0.33
        
        ww = 1/3
        
        0.33
  - - - genotypes of one type / Total # of individuals
- - - - no genetic drift
        
        population is so large allele frequencies do not change
        
        due to random sampling effects
      - no migration
      - no natural selection
      - random mating
      - no new mutations
  - - - Factors
        
        mutation
        
        change in on of the nucleic acids
        
        some are apparent in phenotype
        
        source of all new alleles
        
        must be in gametes to be inherited
        
        male pollen sperm
        
        female ovule egg
        
        Multiple Mutations Leads to
        
        Polymorphism
        
        Dimorphic
        
        2 phenotypes
        
        Dominant-recessive systems
        
        polymorph
        
        many phenotypes in a population
        
        EX:
        
        Aquilegia
        
        3 more items...
        
        natural selection
        
        One allele selectively advantageous
        
        In this example, 2 (triangle) has more vigorous offspring
        
        Over time, individuals with the 2 genotype are able to reproduce more and grow in numbers
        
        The overall vigor of the population grows
        
        So does population size
        
        Artificial Selection
        
        Selection by Humans
        
        increased frequency of desired trait
        
        elimination of undesirable traits
        
        crop breeders for thousands of years
        
        EX: Brassica
        
        Patterns of Natural Selection
        
        Frequency Distributions
        
        Steps
        
        Find your Min & Max values
        
        Determine the number of bins
        
        Count the number of observations for each bin
        
        Draw bars for each bin with the frequency
        
        Directional Selection
        
        single phenotype is favored, causing the allele frequency to continuously shift in one direction
        
        x0≠x1
        var0=var1
        
        Stabilizing Selection
        
        individuals with moderate or average phenotypes are more fit (more likely to survive and reproduce)
        
        x0=x1
        var0>var1
        
        Disruptive Selection
        
        individuals of intermediate phenotype are less fit than those of both higher and lower phenotype, such that extremes are favored
        
        x0=x1
        var0<var1
        
        Natural Selection or Not
        
        Death does not mean natural selection has occurred
        
        Differential survival
        
        Survival due to phenotypes that are heritable
        
        Phenotype coded by genotype
        
        Related to Molecular Genetics
        
        Within a population there is allelic variation arising from various factors such as mutations causing differences in DNA sequences
        
        Distinct alleles may encode proteins of differing functions
        
        Some alleles may encode proteins that enhance an individual’s survival or reproductive capacity
        
        Individuals with beneficial alleles are more likely to survive and reproduce
        
        Over the course of many generations, allele frequencies of many different genes may change through natural selection
        
        This significantly alters the characteristics of a species
        
        The net result of natural selection is a population that is better adapted to its environment and/or more successful at reproduction
        
        genetic drift
        
        random loss of alleles
        
        acts most strongly in small populations relative to a large bottleneck effect
        
        large population dimished suddenly
        
        natural catastrophe
        
        migration
        
        may increase in size again
        
        unlikely to regain original diversity
        
        Adaptive radiation
        
        bottleneck from long distance dispersal
        
        followed by adaptive radiation
        
        ex: Hawaiian lobeliads
        
        migration
        
        movement of alleles into and our of population
        
        immigration
        
        in
        
        emigration
        
        out
        
        can be impeded by
        
        environment
        
        life history
        
        Repercussions for
        
        GMO
        
        climate change
        
        speciation
        
        nonrandom mating
        
        plants "choose" their mates
        
        pollinator vectors
        
        pollination syndromes
        
        some of the individuals reproduce more than others
        
        based on individual phenotypes
        
        sexual selection
        
        male-male competition
        
        excess of pollen grains
        
        pollen tubes can interfere with one another
        
        female choice
        
        barriers on stigma surface preventing germination
- - - - P
        
        dominant allele
        
        A
      - q
        
        recessive allele
        
        a
      - always adds up to 1
  - - - p^2
        
        homozygous dominant genotype
        
        AA
      - 2pq
        
        heterozygous genotype
        
        Aa
      - q^2
        
        homozygous recessive
        
        aa
      - always adds up to 1
- - - - N
        
        Population Size
        
        Exponential Growth
        
        J-shaped curve
        
        Unlimited resources
        
        dN/dt = (r) * (N)
        
        Logistic Growth
        
        Typical of a population that
        
        self regulates
        
        has a carrying capacity
        
        K
        
        2 more items...
        
        S Shaped curve
        
        dN/dt = (r) (N) [1 - (N/K)]
        
        Can similar model predator-prey growth and the impact each has on the other
      - r
        
        intrinsic growth rate
        
        r Selected Species
        
        Grow exponentially
        
        Disturbed areas
        
        Weedy
        
        Annuals
        
        Little investment in defense
        
        Many, small fruits
      - dN/dt
        
        population change over time
        
        +: grow
        
        (-) : shrink
  - - - result: many strategies
        
        Grime's Model
        
        stress
        
        resource availability
        
        Water
        
        Nutrients
        
        Light
        
        Growth Inhibitors
        
        temperature
        
        toxins
        
        Disturbance
        
        biotic
        
        Herbivory
        
        Pathogens
        
        Anthropogenic
        
        abiotic
        
        fire
        
        wind
        
        3 life stages
        
        C- competitors
        
        S- stress tolerators
        
        R- ruderals
  - - - Range of interactions
      - Beneficial interactions +
      - Negative interaction -
      - Facilitation (+/+)
        
        Benefits both
        
        Mutualism
        
        Pollination
      - Commensalism (0/+)
        
        Benefits one, neutral to the other
      - Amensalism (0/-)
        
        Negative to one & neutral to other
      - Competition (-/-)
        
        Both are negatively impacted
        
        Competition for resources
      - Predation (+/-)
        
        Herbivory
        
        Parasitism
        
        Predator - Prey Interactions
        
        Predator
        
        P
        
        negative impact on prey
        
        predator positively impacted by prey
        
        Prey
        
        N
        
        Positive impact on predator
        
        negatively impacted by predator
        
        population sizes are influenced by each other
        
        Predator-prey cycling
        
        At low prey and predator population sizes, prey increase exponentially
        
        As more food for predators is available, predator survival and reproductive success increases, resulting in predator population growth following that of their prey
        
        As predator populations increase, prey death rate exceeds birth rate, resulting in prey decline
        
        As prey number declines, there is not enough food to sustain a high predator population and thus predator death rate exceeds that of birth rate
        
        Lotka-Volterra models
        
        dN/dt = rN - aNP
        
        dN/dt=rate of change with time of the prey population
        
        r=intrinsic rate of increase for prey
        
        N=number of prey individuals
        
        a=predator’s per capita attack rate
        
        Number of prey eaten per predator per unit time
        
        P= number of predator individuals
        
        dP/dt = faNP - qP
        
        dP/dt= rate of change with time of predator population
        
        f=constant, indicating predator’s efficiency at converting the prey it has eaten into new predators
        
        q=predator’s per capita mortality rate
        
        Practice
        
        Prey population change
        
        The number of prey N = 1200,
        
        rate of capture or the predation constant a = 0.004,
        
        Intrinsic growth rate, r = 0.7 = and
        
        Number of predators, P = 130?
        
        dN/dt = rN-aNP
        
        Predator population change 2
        
        N = 1200,
        
        a = 0.004,
        
        f = 0.025 predator birth constant,
        
        q = 0.12 predator death constant
        
        and P = 130 number of predators
        
        dP/dt = faNP-qP
- - - - age
    - - number of individuals alive at age x
    - - survivor rate
        
        proportion of individuals of age x that survive to age x+1
        
        Nx+1/Nx
        
        Nx+1
        
        means next row number alive
        
        Nx
        
        number alive row currently on
    - - survivorship
        
        proportion of individuals that surive from birth (age 0) to age x
        
        Nx / No
        
        No: beginning N at age (x) 0
        
        Nx: Row on
        
        Survivorship Curves and Age Structure
        
        How long did individuals survive
        
        Visual representation of survivorship
        
        Type I, typical of K-selected species
        
        Example
        
        Poa annua
        
        Survivorship curves are plotted logarithmically
        
        Take survivorship (lx) and multiply by 1000
        
        Take the log10 of this value
        
        Plot against age to produce a figure
        
        Type III, typical of r-selected species
        
        Dependent on environment
        
        Same species can display all 3
    - - Fecundity
        
        avg. # of offspring born to female while she is age x
    - - individ fecundity
        
        avg. number of offspring per capita at age x
        
        Ix * Fx
    - - age-weighted fecundity
        
        Ix Fx x
    - - Ro
        
        Net reproductive rate
        
        sum of the offspring per individ column
        
        sum (Ix * Fx)
        
        Expected # offspring individ will produce over its lifetime in the population
        
        R0 > 1
        
        population size increases
        
        Ro < 1
        
        population size decreases
        
        Ro = 1
        
        population size stays the same
      - G
        
        mean generation time
        
        sum of age-weighted fecundity divided by net reproductive rate
        
        (sum Ix Fx x column) / (Ro)
        
        net reproductive rate
        
        Represents average time between two consecutive generations in the lineage of a cohort
        
        The average age between parent and offspring
        
        For humans, typically 20-35 years of age
      - r
        
        intrinsic growth rate
        
        natural log of the net reproductive rate / mean generation time
        
        r>0
        
        population size increases
        
        r<0
        
        population size decreases
        
        r=1
        
        population size doesn't change