BIO 311D Lecture Notes - Lecture 16: Song Sparrow, Doubling Time, Density Dependence
Document Summary
Bio 311d, dr. donald levin, lecture #16, 24 february 2017 (all i(cid:373)ages are take(cid:374) fro(cid:373) dr. Le(cid:448)i(cid:374)"s le(cid:272)ture slides, (cid:449)hi(cid:272)h are a(cid:448)aila(cid:271)le o(cid:374) his (cid:449)e(cid:271)site http://www. sbs. utexas. edu/levin/bio311d/) Demography, continued (reminder that the next exam is on march 24) Review from last lecture: human population levels throughout history, population density based on birthrates and death rates. Density dependence in a song sparrow population: as the number of adults in the population increases, the juvenile mortality rate increases, main point: the larger the population, the less reproductive success and the higher death rates. Average death/birth rates: world: 21 births per thousand people and 9 deaths per thousand people. Birthrate is higher, so the population is growing: developed countries: 11 birthrate, 10 death rate. Small discrepancy, so has slower population growth than developing countries: developing countries: 24 birthrate, 8 death rate. Huge difference between birthrate and death rate, so a faster growing population: africa: 38, 14.
