Biology 1B, Ecology Lecture 4, Page 1 Professor Resh • Spring 2007*Assigned readings, 7th Edition pp. 1139-1143, 1148-11526th Edition pp. 1151-1158, 1163-1168DemographyOutline of Lecture 4A. Demography1. Survivorship or Death Schedule2. Survivorship curvesB. Reproductive patterns1. Semelparous2. IteroparousC. r-selected and K-selected populationsD. Idealized r and k species traitsA. Demography1. Survivorship or Death Schedule3. Survivorship curves(see Fig. 52.4 on p. 1087 of text, 5th Edit.)(see Fig. 52.3 on p. 1155 of text, 6th Edit.)Age1.00.1.01logx12345% of maximum life span1.00.1.01logx12345Biology 1B, Ecology Lecture 4, Page 2 Professor Resh • Spring 2007*Assigned readings, 7th Edition pp. 1139-1143, 1148-11526th Edition pp. 1151-1158, 1163-1168DemographySurvivorship curves con’t5 3.4B. Reproductive patterns1. Semelparous: reproduce in oneepisode2. Iteroparous: reproduce repeatedlyC. r-selected populations: individualsreproduce at an early age, semelparous,have large clutch sizesK-selected populations: reproduce later,iteroparous, have fewer offspring,parental care.net reproductive rateor replacement rate3,400/1,000=3.41. If net reproductive ratio (Ro)=1, femalereplaces herself; Ro>1 population grows;Ro<1 population decreases% life span1000100% time spentin reproductionBiology 1B, Ecology Lecture 4, Page 3 Professor Resh • Spring 2007*Assigned readings, 7th Edition pp. 1139-1143, 1148-11526th Edition pp. 1151-1158, 1163-1168DemographyD. Idealized r-selected and k-selectedpopulationHow would they differ in terms of?• maturation time (short or long)• lifespan (short or long)• death rate (high or low)• number of offspring per reproductive• episode (many or few)• number of reproductions per lifetime(one or several)• timing of first reproduction (early orlater in life)• size of offspring (small or larger)• parental care (none or extensive)*Note: The sum of all species traits involve
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