The Nature of ThingsPopulation DynamicsHuman Population● Guide to Obtaining a Sustainable Earth● Review of reading, “The Nature of Things”○ Written about by Harvard prof. in “Swerve” popular book, author Stephen Greeblatt○ discovered by early Italian Renaissance (academic revolution after dark ages)○ began scanning churches for any books insight to Greeks.○ Epicurus Thought:■ what you feel, look, taste, feel■ the world is built off what you sample of it. ■ we try to avoid pain, try to achieve pleasure. ■ https://en.wikipedia.org/wiki/Epicureanism■ you use information to minimize pain, which brings happiness.○ Currently, society is heading toward Fundamentalism (terrorists) vs. Environmentalism. there could be an underlying reason.■ Bruno = follower of Epicurus, was burned at stake.■ statue erected in Coupe de Fiori in ROme.■ Botticelli’s Primavera > Venus = patron of nature. based on opening lines of “The Nature of THings”○ Elements of movement cycle between abiotic (non-living) and biotic (living) world.■ https://en.wikipedia.org/wiki/Abiotic_component○ “Seed” = he refers to origins of birth. cycle of life. But why? >Not answered till Darwin.● **Keep up with SimuText!!**● Take age, divide by max age of species, then reached by individuals in species.● % of survival varies between species.○ fish die out early, so must reproduce many at a time.○ birds die at constant rate○ mammals die later on/late loss, so reproduce less, but nurture longer.● Reproduction Patterns○ r-selected species = opportunistic○ k-selected species = competitors■ slowly. high probability of surviving.○ Dynamics are simple: birth rates and death rates■ = If Birth rate is greater than death rate, then exponential growth.■ unchecked power = dangerous!● Population growth○ we are in the mammalian era (vs. amphibians, bacteria, cretacean eras, etc.)○ currently mammals are the only type exploding (growing exponentially)○ Intrinsic Growth Rate = r○ **see Powerpoint graphs!**○ Danger of exponential growth systems can be seen with the deer/caribou in Alaska. ■ they grew over capacity (population overshoot), then population crashed, because ran out of resources to feed themselves. so gradually withered themselves out.○ Q: What keeps populations in a relatively constant value?■ Ans: Bottom up (limiting of birth rate) vs. Top down (controlling of death rate)■ If in the equation dN/de = rN (1-N/K), N = capacity, then 1-1 = 0, and it willlimit.■ ie. they must equal, then subtract out, and thus will remain constant instead of growing or decreasing.○ Population growth throughout countries■ places of rapid population growth seem to be stressing on already stressed environments. ■ US + Europe up, then drop■ Latin America + Africa, up■ Asia - continually high○ Demographic Column - age distribution comparison■ when graph is straight up and down, like a skyscraper, shows population constant■ when graph is like pyramid, less old people show rapidly growing population○ Demographic Transition■ Crude rate = # x 1000■ # of crude birth rates drops first, then # of crude death rates follows, to become a S.S. (Steady State) ● Q: What determines women’s fertility?○ Ans: Education, empowerment of women, urbanization,