AEC 360  Ecology

The environment and the spread of human civilization

I.  What has controlled the abundance of humans?
    A.  The development of agriculture

    B.  Why did agriculture arise in some places but not others?
        1.  Dependent on environment, including climate

        2.  Appropriate set of domesticable plants and animals

        3.  Probably not due to time of colonization

    C.  Agriculture arose in the Fertile Crescent because:
        1.  Appropriate set of domesticable food plants (cereals, pulses, fibers)

        2.  Mediterranean climate

        3.  Nearly all large domesticated animals

    D.  Of 350,000 plant species, what are the characteristics of the few hundred that have become domesticated?
        1.  Edible and high yields in wild
        2.  Easily grown after being sown or planted
        3.  Grow quickly, could be harvested within months
        4.  Easily stored
        5.  Self-pollinated

    E.  Characteristics of Mediterranean climate
        1.  Seasonally dry biomes
        2.  Require plants to grow rapidly
        3.  Many annuals that allocate production to larger seeds
        4.  Seeds wait for rain to germinate

    F.  Characteristics of domesticable animals

        1.  Diet herbivore
        2.  Growth rate fast
        3.  Captive breeding easy
        4.  Disposition pleasant, calm
        5.  Social structure herds, hierarchical

    G.  Importance of domesticated animals in the fates of human civilization

        1.  Major source of protein
        2. Manure used as fertilizer
        3.  Perform work in agriculture
        4.  Acquisition of disease

II.  Implications of agricultural lifestyles

    A.  What are the mechanisms and consequences of evolution for human epidemics?
        1.  Epidemics are crowd diseases, require high population densities
        2.  Sedentary populations live near sewage
        3.  Cities trade, providing routes for disease
        4.  Diseases evolve in virulence and host compatibility

    B.  Contols on the distribution of humans

        1.  East-west axis

    C.  Changes in human distributions affected other species


    D.  Education, technology, and political organization are consequences of environmental factors 

        1.  Agriculture allowed societies to become sedentary
        2.  Abundant food production permitted individuals to allocate time to other endeavors
        3.  High population densities permitted rapid interchange of ideas

III.  Questions for thought

    A.  Why did Europeans colonize the rest of the world?

        -Determined by the environment
        -Agriculture -> sedentary lifestyle  technology
        -Diseases spread from Europeans to indigenous people, not vice versa

    B.  Why not another technologically advanced society, like China?

    C.  Why did some human populations collapse?

    D.  How might the environment impact future human civilizations?