BIOL 1108 1nd Edition Lecture 22 Outline of Last Lecture I. Learning ObjectivesII. DefinitionsIII. Animal Signs and CommunicationIV. Linking Experience and BehaviorV. Survival and ReproductionVI. Inclusive Fitness and AltruismVII. DispersalOutline of Current Lecture I. Learning ObjectivesII. Defining PopulationsIII. BideIV. Population Monitoring V. DemographyVI. Life-history VII. Population ModelsVIII. Population RegulationCurrent LectureI. Learning Objectives These 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.- Describe how life-table and survivorship curves represent populations over time- Describe trade-offs between survival and reproduction (life history traits)- Relate population growth to organisms’ environments (abiotic and biotic)II. Defining Populations- Population- a group of individuals of the same species that live in the same general area (i.e, potential of interacting)o Abundance- the number of individuals- Density- the number of individuals per unit area or volume- Dispersion (distribution)- the spacing of individuals in a populationo Affected by resources Clumped Uniform Random III. Bide- B: births- I: immigrationo Births and immigration add individuals to a population- D: deaths- E: emigration o Deaths and emigration remove individuals from a populationIV. Population Monitoring- Observe what animals are doing- Mark and recaptureo For birds: attach red and aluminum bands on their legsV. Demography - Demography- the study of vital statistics of populations and how they change over timeo Ex. Survival rates, emigration, ect.o Death rate for females is less than males- Life-tables- age specific summaries of survivalo Typically of a cohort (same age individuals)- Survivorship curves- graphical representationo The proportion or numbers of a cohort alive at each ageo 3 types Type 1: death rate is high once reaching a certain age- Ex. Humans Type 2: constant life line- Ex. Groundhog  Type 3: most deaths when they are young, but if they survive they live a long life- Ex. Sea turtles VI. Life- history- Traits that affect organism schedule of reproduction and survival- It’s about trade-offso Semelparity- puts lots of energy into benefitting offspring for survival; “put all eggs in a basket” o Iteroparity- longer period of time to take care of one offspring, multiple time- Depends on how often an individual reproduces, parental care, and age of reproductionVII. Population Models - Change in population size over time= (B + I) – (D+ E)- Patterns of population growtho Populations grow by multiplication (exponentially)- Logistic growtho dN/dt= rN (1- N/K)o r= finite rate of increase under ideal conditionso N= current population sizeo K= carrying capacity VIII. Population Regulation- What processes contributes to change in population size?o Births and deathso Dispersal (immigration/ emigration)- What forces become more important as density increases?o Population will fluctuate around carrying capacity o Extrinsic forces must be affecting these processes more as density increases - What factors might decrease births, increase mortality, or increase dispersal out of an area when density increases? o Limiting resources (competition) Places to live- nesting sites/ territories/ space Foodo Pathogens (diseases) Transmission rate increases with densityo Predators and parasites Easier to detect/ capture prey/ host when density is high- These are called DENSITY-DEPENDENT FACTORS: effect on birth rates, death rates, and dispersal rates changes as population density changes- Because density dependent factors respond to population density, they can REGULATE populations- Density- Independent factors: effect on birth and death rates are independent of population sizeo Affects population size drasticallyo Ex. Temperature, precipitation, storms, droughts, invasive