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Genetics and Ecology - Coggle Diagram

- - - - J-shaped curve
      - Unlimited resources
    - - S-shaped curve
      - Typical of a population that
        
        self regulates
        
        Has a carrying capacity (K)
  - - - Relevant for r > 0
    - - dN over dt equals r times N
    - - dN over dt equals r times N times the quantity one minus N divided by K
  - - - dN/dt = rN
    - - dN/dt = rN[(K-N)/K] =
        
        rN(1-N/K)
  - - - Grow exponentially
      - Disturbed areas
      - Weedy
      - Annuals
      - Little investment in defense
      - Many, small fruits
    - - Fluctuate around carrying capacity
      - Fairly stable habitats
      - Perennials
      - Invest in defenses
      - Resource-intensive fruits
  - - - Resource availability
        
        Water
        
        Nutrients
        
        Light
      - Growth inhibitors
        
        Temperature
        
        Toxins
    - - Biotic
        
        Herbivory
        
        Pathogens
        
        Anthropogenic
      - Abiotic
        
        Fire
        
        Wind
    - - C- competitors
      - S- stress tolerators
      - R- ruderals
- - - - 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
  - - - Benefits both
      - Mutualism
      - Pollination #
    - - Benefits one, neutral to the other
    - - Negative to one & neutral to other
    - - Both are negatively impacted
      - Competition for resources
    - - Herbivory
      - Parasitism
  - - - P
      - Negative impact on prey
      - Positively impacted by prey
    - - N
      - Positive impact on predator
      - Negatively impacted by predator
      - Population sizes are influenced by each other
  - - - 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= 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
- - - - Nx+1/Nx
    - - Nx/N0
  - - - 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
- - - - Number of copies of an allele in a population divided by the total number of alleles for that gene in a population
    - - Number of individuals with a particular genotype in a population divided by the total number of individuals in a population
    - - Number of copies of an allele in a population
      - Divided by
      - The total number of all alleles for that gene in a population
  - - - Change in one 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
    - - Dimorphic
        
        2 phenotypes
        
        Dominant-recessive systems
      - 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
        
        Large population diminished suddenly
        
        Natural catastrophe
        
        Migration
        
        May increase in size again but unlikely to regain original diversity
    - - 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
    - - Movement of alleles into and out of a population #
        
        Immigration
        
        Into
        
        Emigration
        
        Out of
      - Can be impeded by
        
        The environment
        
        Life history
      - Repercussions for
        
        GMO and
        
        climate change
        
        speciation
    - - 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
        
        Increased frequency of desired trait
        
        Elimination of undesired traits
      - Crop breeders for thousands of years
      - Example Brassica
- - - - 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
    - - 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
        
        Cross pollination vs
        
        Self pollination
    - - three principles
        
        Dominance
        
        Segregation
        
        Independent Assortment
      - principle of 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
        
        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)
        
        Homozygosity, both alleles are the same
      - principle of 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
        
        One from each parent
        
        Inherit a homologous chromosome
        
        During meiosis, 2 members of a gene pair separate from each other
        
        Each gamete has an equal chance to inherit either one of the genes
      - monohybrid cross
        
        Punnett square
        
        Visual representation of the offspring inheritance patterns
        
        Monohybrid is a cross between 2 homozygous parents with different alleles.
      - principle of 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
    - - 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
    - - One gene interacts with another
      - may interfere or mask
    - - 4 haploid genotypes
      - Not produced in equal numbers
        
        Recombinants less abundant
        
        Parentals more abundant
    - - Single gene with multiple effects on the phenotype
      - Inheritance of a single gene which visibly influences several traits
    - - Having more than two copies (2n) of a chromosome
      - Autopolyploid
        
        Failed meiosis
        
        Self fertilization
      - Allopolyploid
        
        Meiotic error
        
        Mismatch during mating
        
        Second mating creates matched pairs