Slide 1

State which species of turtle nests in the greatest numbers on Jupiter Island. (1 mk)(b)Compare the distribution of nesting in the three species of turtle along the eastern coastline of Florida. (2 mks)Happy Wed!9/8/2010(a)loggerheads / Caretta caretta1(b)all three species nest over the same range of latitudeson the same beaches/areas;density of loggerheads is greatest and leatherbacks is lowest;similar relative densities/numbers on the different beaches / latitudes;all three had most nests on Jupiter;more loggerheads at northern end of range /(Do not accept answers givingaround 28 (N) / on Melbourne;) the range 2628 or 2630.)2 max

Ill CHECK your IB Journal on quiz day for 5.1 and 5.3Dont forget...Exercises ?s as you read or after weve gone over in classMake sure you GET ITPractice ?s @ end of chapter old exam ?sStudying for quizzes/tests!

5.3Populations5.3.1Outline how population size is affected by natality, immigration, mortality and emigration.5.3.2Draw and label a graph showing a sigmoid (S-shaped) population growth curve.5.3.3Explain the reasons for the exponential growth phase, the plateau phase and the transitional phase between these two phases.5.3.4List three factors that set limits to population increase.

5.3.1 Factors affecting pop size

5.3.2 Pop growth curvesMODELChange in pop size over timePop expanding into a habitat offering INITIAL LOW RESISTANCE or LOW LIMITING FACTORSA-Exp = rapid pop growth rateB-slowing but still high C-plateau = pop remains stable w/time;slight oscillations

5.3.3 Phases of pop growth curvedetails!EXPONENTIAL PHASELow/reduced limiting factorsPop expands exponentially into hab. @ 2n where n= # of generationsnatality + imm. > mortality + emigr.Note that it does not mean that death/ emigration= 0 !!!When do you observe exp. phase in nature?Pop of germinating annual plants in new seasonBacterial pop @ onset of infectionSuccessionany species pop entering previously uninhabited area5.3.3 TRANSITION PHASEResources reduced, become limitingCompetitionnot all surviveNATURAL SELECTION! lower rate of increase in pop5.3.3 POPULATION PLATEAUPop remains constant over time/generationsNatality + imm = mortality + emigPop size determined by CARRYING CAPACITY of habitat @ that timeWhat factors affect the rate of growth of a population?

What factors LIMIT pop growth of a species?

5.3.4 Factors limiting pop growthWith unltd resources, pop would keep increasingexponentially!REALITY CHECK!Environmental resistance limits it & determines carrying capacityShortage of food/preyPredation, parasitismDiseaseAccumulation of wasteShortage of space/territory

Food for Thought...