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Evolution, Biodiversity, and Population Ecology - Coggle Diagram

- - - - Environmental pressures select for increases of traits in populations - example is human skin color
      - What produces all this variation?
        
        Mutation- accidental changes in DNA that may be passed on to the next generation - This randomly changes traits , Often they are harmful may be selected against
        
        Mutation introduces new genetic variability into population -
        Sexual reproduction maintains variability in a population
      - Speciation - Defined by speciation = the development of so many differences between populations that their individuals can’t reproduce anymore- They are now separate species
      - Evidence of natural selection is all around us
        Artificial selection = the process of selection conducted under human direction
        Produced the great variety of dog breeds and food crops
        
        We can see the history of diversification by Phylogenetic trees = diagrams that show relationships among species, groups, genes, etc.
        
        Fossil will help to show how old an organism is
    - - DNA (Deoxyribonucleic Acid) codes for proteins Each protein is coded for by one gene
        
        Biotic Potential - an organism capacity to reproduce off springs ( kids)
  - - - Related species in different environments experience different pressures and evolve different traits
        
        Divergent evolution = speciation, accumulation of differences between two populations over time. DOGS AND WOLVES
        
        Convergent evolution = unrelated species may acquire similar traits because they live in similar environments - EX - BIRDS BATHS AND BUTTERFLY
- - - - Population distribution (dispersion) =
        spatial arrangement of organisms
        
        Random = haphazardly located individuals, with no pattern - Trees
        
        Uniform = individuals are evenly spaced Territoriality, competition - Pinguins
        
        Clumped = organisms found close to other members of population - Most common in nature , Clustering around resources , Mutual defense - Fish
        
        Birth Rates and Death Rate
        
        Survivorship curves = graphs that show that the likelihood of death varies with age
        
        The influence of some factors depends on population density
        
        Density-dependent factors = limiting factors whose influence is affected by population density -
        
        Increased density increases the risk of predation, disease, and competition
        
        Results in the logistic growth curve
        
        Larger populations have stronger effects of limiting factors
        
        Density-independent factors = limiting factors whose influence is not affected by population density- Events such as floods, fires, and landslides
        
        Type I: higher death rate at older ages - Larger animals (e.g., humans)
        
        Type II: same death rate at all ages - Medium-sized animals (e.g., birds)
        
        Type III:** higher death rate at young ages-** Small animals, plants
      - The influence of some factors depends on population density
  - - - Habitats vary with the body size and needs of species
      - Species have different habitat needs at different times- Migratory birds use different habitats during migration, summer, and winter
      - Species use different criteria to select habitat- Soil, topography, vegetation, other species - Water temperature, salinity, prey -
      - Water temperature, salinity, prey -
      - Species survival depends on having
  - - - Specialists = species that have narrow niches and specific needs - Extremely good at what they do But vulnerable when conditions change
      - Generalists = species with broad niches
        
        Use a wide array of habitats and resources
        
        Can live in many different places