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rmax, generation time and body sizeExponential population growthDemographic and environmental stochasticityOptimal reproductive tacticsSemelparity versus iteroparityReproductive effort (parental investment)Expenditure per progenyParent-offspring conflictPatterns in Avian Clutch SizesAltrical versus PrecocialNidicolous vs. NidifugousDeterminant vs. Indeterminant LayersOpen Ground NestersOpen Bush Nesters Open Tree Nesters Hole NestersNest attentiveness and male feedingFlicker egg removal experiment N = 5290 Species
Great Tit Parus major David Lack
Seabirds (N. Philip Ashmole) Boobies,Gannets, Gulls, Petrels, Skuas, Terns, Albatrosses Delayed sexual maturity, Small clutch size, Parental care
Albatross Egg Addition Experiment An extra chick added to each of 18 nests a few days after hatching. These nests with two chicks were compared to 18 other natural “control” nests with only one chick. Three months later, only 5 of the 36 experimental chicks survived from the nests with 2 chicks, whereas 12 of the 18 chicks from single chick nests were still alive. Parents could not find food enough to feed two chicks and most starved to death. Diomedea immutabilis
Latitudinal Gradients in Avian Clutch Size Daylength Hypothesis Prey Diversity Hypothesis Spring Bloom or Competition Hypothesis
Latitudinal Gradients in Avian Clutch Size Nest Predation Hypothesis Alexander Skutch ––––––>
Latitudinal Gradients in Avian Clutch Size Hazards of Migration Hypothesis Falco eleonora
Evolution of Death RatesSenescence, old age, genetic dustbin Medawar’s Test Tube Modelp(surviving one month) = 0.9p(surviving two months) = 0.92p(surviving x months) = 0.9xrecession of time of expression of the overt effects of a detrimental alleleprecession of time of expression of the effects of a beneficial allele Peter Medawar
Age Distribution of Medawar’s test tubes
Percentages of people with lactose intolerance
Joint Evolution of Rates of Reproduction and Mortality Sceloporus Donald Tinkle
J - shaped exponential population growth http://www.zo.utexas.edu/courses/THOC/exponential.growth.html
Instantaneous rate of change of N at time tis total births (bN) minus total deaths (dN)dN/dt = bN – dN = (b – d )N = rNNt = N0 ert (integrated version of dN/dt = rN)log Nt = log N0 + log ert = log N0 + rtlog R0 = log 1 + rt (make t = T)r = log l or l = er (l is the finite rate of increase)
Once, we were surrounded by wilderness and wild animals, But now, we surround them.
Verhulst-Pearl Logistic Equation dN/dt = rN – rN (N/K) = rN – {(rN2)/K}dN/dt = rN {1– (N/K)} = rN [K/K – N/K]dN/dt = rN {1– (N/K)} = rN [(K – N)/K] dN/dt = 0when[(K – N)/K] = 0[(K – N)/K] = 0when N = K dN/dt = rN (1 – N/K) = rN – (r/K)N2