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Exam 5 - Coggle Diagram

- - - - Population size (N)
      - Logistic growth
        
        Typical of a population that
        
        has a carrying capacity (k)
        
        self regulates
        
        S-shaped curve
      - Exponential growth
        
        Unlimited resources
        
        J-shaped curve
    - - Result in die off
        
        Limited resources
        #
      - Overshoot K
    - - N = population size
      - K = carrying capacity
      - dN/dt = population change over time
      - Exponential growth
        
        dN over dt equals r times N
      - Logistic growth
        
        dN over dt equals r times N times the quantity one minus N divided by K
    - - r = intrinsic growth rate
      - Logistic growth
        
        rN(1-N/K)
        
        dN/dt = rN[(K-N)/K] =
      - Exponential growth
        
        dN/dt = rN
    - - K-selected
        
        Fluctuate around carrying capacity
        
        Fairly stable habitats
        
        Perennials
        
        Invest in defenses
        
        Resource-intensive fruits
      - r-selected
        
        Grow exponentially
        
        Disturbed areas
        
        Weedy
        
        Annuals
        
        Little investment in defense
        
        Many, small fruits
    - - Plants must make trade-offs due to environmental necessities
      - Many strategies exist
      - Grime’s model
        
        Stress
        
        Resource availability
        
        nutrients
        
        light
        
        water
        
        growth inhibitors
        
        toxins
        
        temp
        
        Disturbance
        
        Biotic
        
        Herbivory
        
        Pathogens
        
        Anthropogenic
        
        Abiotic
        
        wind
        
        fire
        
        3 life stages
        
        C- competitors
        
        S- stress tolerators
        
        R- ruderals
  - - - x = age
      - Nx= number of individuals alive at age x
      - Sx= proportion of individuals of age x that survive to age x+1;
      - Nx+1/Nx
      - lx= proportion of individuals that survive from birth (age 0) to age x;
        
        Nx/N0
      - Fx= average number of offspring born to a female while she is age x
      - lx(Fx) = average number of offspring per capita at age x
      - lx(Fx)x = average number of offspring per capita at time x, weighted by age x
    - - Calculate the net reproductive rate (R0)
      - Calculated by taking the sum of the offspring/individual column.
      - Represents the expected number of offspring an individual will produce over its lifetime in the population.
        
        If R0>1, the population size increases.
        
        If R0<1, the population size decreases, and
        
        if R0=1, then population size does not change.
    - - Calculate the mean generation time (G)
      - Calculated by taking the sum of the Age-weighted fecundity column and then dividing by the 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
    - - Calculate the intrinsic growth rate (r)
      - Calculated by taking the natural log of the net reproductive rate divided by the mean generation time.
        
        If r>0, the population size increases.
        
        If r<0, the population size decreases, and
        
        if r=1, then population size does not change.
    - - How long did individuals survive
      - Visual representation of survivorship
      - Type I, typical of K-selected species
      - Type III, typical of r-selected species
      - Dependent on environment
      - Same species can display all 3
    - - 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
      - Example: Type I curve
  - - - a group of actually or potentially interacting species living in the same location.
      - bound together by a shared environment and a network of influence each species has on the other.
      - factors affecting interactions include
        
        abiotic environment
    - - 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 (-/-)
        
        Competition for resources
        
        Both are negatively impacted
      - Predation (+/-)
        
        Parasitism
        
        Herbivory
    - - Predator
        
        P
        
        Negative impact on prey
        
        Positively impacted by prey
      - Prey
        
        N
        
        Positive impact on predator
        
        Negatively impacted by predator
      - Population sizes are influenced by each other
    - - r = intrinsic growth rate
      - N = population size
      - K = carrying capacity
      - dN/dt = population change over time
      - Exponential growth
      - Logistic growth
      - Can similar model predator-prey growth and the impact each has on the other
    - - 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
    - - 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
- - - - A population is a group of individuals of the same species that occupy the same region and can interbreed with each other
      - All of the alleles of every gene in a population make up the gene pool
      - Allele & Genotype Relative frequencies
        
        Allele frequency
        
        Number of copies of an allele in a population divided by the total number of alleles for that gene in a population
        
        Genotype frequency
        
        Number of individuals with a particular genotype in a population divided by the total number of individuals in a population
    - - predicts an equilibrium-unchanging allele and genotype frequencies from generation to generation-if certain conditions exist in a population
        provides a quantitative relationship between the allele and genotype frequencies
      - No new mutations
      - No genetic drift. The population is so large allele frequencies do not change due to random sampling effects
      - No migration
      - No natural selection #
      - Random mating
      - Frequencies in populations add up to 1
    - - Multiplying the allele frequencies gives the proportion of each allele combination in the population.
      - The frequency of gametes carrying a particular allele is equal to the allele frequency for a population in Hardy-Weinberg equilibrium.
  - - - Factors
        
        Mutation
        
        Natural selection
        
        Genetic drift
        
        Migration
        
        Nonrandom mating
      - Changes in a population’s gene pool from generation to generation
    - - Change in one of the nucleic acids
      - Some are apparent in phenotype
      - Source of all new alleles
      - Must be in gametes to be inherited
    - - Dimorphic
        
        Dominant-recessive systems
        
        2 phenotypes
      - Polymorph = many phenotypes in a population
      - Example: Aquilegia
      - Color variation
      - Spur-length variation
      - Can be due to a single nucleotide polymorphism
    - - Random loss of alleles
      - Acts most strongly in small populations relative to large
      - Bottleneck effect
        
        May increase in size again but unlikely to regain original diversity
        
        Large population diminished suddenly
        
        Migration
        
        Natural catastrophe
    - - Plants “choose” their mates
      - Pollinator vectors
        
        Pollination syndromes
      - Some of the individuals reproduce more than others
        
        Based on individual phenotypes
      - Sexual Selection
        
        female choices
        
        Barriers on stigma surface preventing germination
        
        Male-male competition
        
        Pollen tubes can interfere with one another
        
        Excess of pollen grains
    - - Can be impeded by
        
        life history
        
        The environment
      - Repercussions for
        
        GMO and
        
        climate change
        
        speciation
      - Movement of alleles into and out of a population
        
        emigration
        
        out of
        
        Immigration
        
        into
    - - Bottleneck from long distance dispersal
      - Followed by adaptive radiation
      - Example: Hawaiian lobeliads
    - - 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
    - - Selection by humans
        
        Elimination of undesired traits
        
        Increased frequency of desired trait
      - Example Brassica
      - Crop breeders for thousands of years
  - - - Death does not mean natural selection has occurred
      - Differential survival
      - Survival due to phenotypes that are heritable
        
        Phenotype coded by genotype
    - - 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
- - - - Each chromosome has a partner
      - Homologous chromosomes
      - Resemble each other in size, shape & hereditary information
      - Each homolog is from a different parent
      - Interactions of genes on each sets of chromosomes determines the genetic characteristics
    - - During Metaphase I
        
        Orientation of bivalents is random
      - During Metaphase II
        
        Orientation of sister chromatids is random
      - In general, the possibilities are 2n
      - Crossing over
        
        During Prophase I
        
        Synaptonemal complex forms
        
        Mixes the genes present in homologous chromosomes
        
        Results in new combinations not present in the chromosomes of the parental cells
        
        Usually at least one chiasma occurs between every pair of homologous chromosomes
    - - New combination of alleles from each parent
      - Promotes heterozygosity
      - Advantages include
        
        genetic diversity
        
        Bet-hedging to novel environments
        
        Multiple deleterious alleles can be bunched together and eliminated
        
        Escape host-parasite negative impacts
      - Pollination
        
        self pollination
        
        Cross pollination vs
  - - - Dominance
        
        Each individual has a unique genotype
        
        Genotype is made up of alleles
        
        Phenotypes determined by these alleles (and the environment)
        
        There is no guarantee that an allele will manifest
        
        Homozygosity, both alleles are the same
        
        Heterozygosity
        
        One of 2 genes (dominant allele) has a detectable effect on an organism's appearance
        
        The other gene has no discernable effect (recessive allele)
      - Segregation
        
        Alleles are segregated, separated, from one another during meiosis
        
        Each gamete contains only one allele for each gene
        
        Offspring inherit 2 alleles for a gene
        
        Inherit a homologous chromosome
        
        One from each parent
        
        Each gamete has an equal chance to inherit either one of the genes
        
        During meiosis, 2 members of a gene pair separate from each other
      - Independent Assortment
        
        Gene pairs that are not related (homologs) segregate independently
        
        Gene pairs that are not linked segregate independently
        
        Evidence provided from a dihybrid cross
        
        3:1 phenotypic ratio for each of the 2 alleles
    - - Punnett square #
      - Visual representation of the offspring inheritance patterns
      - Monohybrid is a cross between 2 homozygous parents with different alleles.
  - - - Phenotype of heterozygote is intermediate between those of parent homozygotes
    - - Many populations have more than 2 alleles for a particular locus
      - Punnett square theoretical crossing works similar
      - Breeding experiments to determine dominance
      - Figuring out alleles is complex
    - - Changes in the genetic makeup of an individual
      - Point mutation
        
        Single nucleotide change
      - Chromosome mutation
        
        Deletion
        
        Segments of chromosome are lost
        
        Duplication
        
        Part of the chromosome has doubled
        
        Inversion
        
        Piece rotates 180
        
        Translocation
        
        Exchange of parts between 2 nonhomologous chromosomes
        
        Transposons
        
        Movable genetic element
        
        Jumping genes
    - - Fail to mix alleles across homologs
      - Chromosome inherited same as parent
      - Only 2 gamete types possible rather than 4
    - - Multiple genes for one character
      - Phenotype is cumulative result of combined effects of many genes
      - Example abscisic acid
      - Most traits
      - Continuous variation
      - Populations tend to have normal distribution
    - - May interfere or mask
      - One gene interacts with another
    - - 4 haploid genotypes
      - Not produced in equal numbers
        
        Parentals more abundant
        
        Recombinants less abundant
    - - Single gene with multiple effects on the phenotype
      - Inheritance of a single gene which visibly influences several traits
      - Ex: awn of wheat
        
        Wheat with awns have greater yield than those without awns
    - - Outcrosser
        
        Large petals
        
        Flower late
        
        Seasonal drought
        
        Physiologically tolerant?
      - Selfer
        
        Small petals
        
        Flower early
        
        Seasonal drought
        
        Physiologically escape?
    - - Having more than two copies (2n) of a chromosome
      - Autopolyploid
        
        Self fertilization
        
        Failed meiosis
      - Allopolyploid
        
        Meiotic error
        
        Mismatch during mating
        
        Second mating creates matched pairs
    - - Polyploid mask deleterious recessive alleles
      - Relax selection pressure
        
        Accumulate mutations that eventually result in beneficial trait
      - 2 groups of ancient duplications
        
        Common ancestor of extant angiosperms
        
        Common ancestor of seed plants