BIOL 1107 1nd Edition Lecture 32Outline of Last Lecture I. Crossing Over (Prophase I)II. Genetic Recombination and Mapping GenesOutline of Current Lecture I. Population ChangeII. Thomas Malthus & Carrying CapacityIII. Passenger Pigeon & Indigenous BirdsCurrent LectureI. Population Change- What causes size of a population to change? Births/deaths o Immigration- “bring people in”’ -> increases populationo Emigration- “take people out” -> decreases population - Population snapshot: o Population = 1000 individuals o Birth rate = 200/yearo Death rate = 100/yearo Q: How big will our population be in 2 years? o A: (200/1000) = 0.2 (birth rate); (100/1000)= 0.1 (death rate) r = 0.20-0.1 = 0.1 1000 X 0.1 = 100 -> 1100 people (1st year) 1100 X 0.1 = 110 -> 1210 people (2nd year) this is an example of exponential growth - (+) positive r-value -> high increase in population growth- (-) negative r-value -> more deaths than birthsII. Thomas Malthus & Carrying Capacity- (1798) environment limiting growth of population - Carrying capacity- the maximum population size of the species that the environment can sustain indefinitely, given the food, habitat, water and other necessities available in the environmentThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.- Carrying capacity- amout of environment left to sustain population o As population size gets closer to carrying capacity, (K-N)/K decreases o Maximum growth occurs @ half of carrying capacity (K)o K = carrying capacityo In the beginning, we don’t have enough size - Q: The intrinsic growth rate for a population per year is 25%. How many individuals would be added to a population of 200 after 1 year if the carryingcapacity of the environment is 1000?o A: 200 X (8/10) = 160o (1000-200)/1000 = (800/1000) = 0.80 (200) = 160 X 0.25 = 40III. Passenger Pigeon - one of the most numerous birds in the planet (used to be)- drove this pigeon to extinction - killed a lot of these pigeons for food- Indigenous birds -> Irony Billed Woodpecker, Carolina Parakeet, Health Hen, Wild Turkey - Environment plays a big role in how populations grow - What environmental feedback can regulate a population size? - Chimps -> population graph (look on elc
View Full Document
Unlocking...