WFSC 403 6th Edition Lecture 22 Outline of Last Lecture I End chapter 13 II Effects of disease on population a Brucellosis b Rabies c Myxomatosis d Tuberculosis III Evolution of host parasite systems a Virulence vs transmissibility IV Chapter 14 V Basic concepts and a simple model Outline of Current Lecture I Basic Concepts of Population Regulation and a simple model a The Question i Figure 14 1 page 257 st b 1 principle and the reverse i Page 259 nd c 2 principle i Page 260 d 2 essays i Page 258 page 260 e Biotic School versus Climate School i Predator and parasite Biotic Density dependent ii Weather climate Density independent Current Lecture Allele affect The per capita birth rates are still density dependent but they are density dependent in a backwards fashion dN rN b d N dt If there was any situation when the birth and death rates did not cross Parallel First Principle o Any population that does not have any per capita birth rate OR per capita death rate stay at equilibrium 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 WFSC 403 613 CH 14 Population Regulation o Population in a closed system will increase until per capita birth rate per capita Populations in a closed system will increase until death rate per capita birth rate per capita death rate o This equilibrium may be researched by increasing death rates decreasing birth First principle of population regulation C C C C C C C C C C C C rates C C C C C C C C C C C C C C or C C C C C both C CCCC This equilibrium may be reached by increasing CC C C C C C C C C C CCCCC C C CC C C CCC CC CC CC CC C CC CC CC C C C C C C C C C Co C C C C C C C C Density CC C dependent and density independent per capita rates death rates decreasing birth rates or both C C C o C C C C C C C C C Inversely C C C C C C C C C C C C C C C C C C C density dependent CC C C per capita rates can never lead to an equilibrium CC C C C C C CC C C C C C CC CC C CC C CCC C C C C C C CC C C C CC CC C C C CC C CCC C CC C CC density Density dependent and density independent per C C C C C C C C C C C C principle C C C C CC C C C CC C C C CCC C Second CC C C C C C C C C CC C C C CC C C CCC CC C CC C capita rates o Differences in equilibrium density between two populations can be caused by C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C CC C CC C C CC C C C C C CC C C CCC CC C CC C C CCCC C CC C C variation in either density dependent or density independent per capita birth and C C C C CCC Inversely denisty dependent per capita rates can death rates never lead to an equilibrium density Two schools of thought o Biotic school Predators Graphic model to show Parasites Differences in equilibrium density between two how2 populationsmay rageDensity dependent differ in ave populations can be caused by variation in either o abundance Climate school density dependent or density independent per Second principleof population Weather capita birth and death rates regulation Density independent C C C C C C C C C C C C C C C C C C C C C C C C C C C Entomologist look at these first so it is natural that they factors say weather Density dependent are affecting C C C C CCC CC C CC C C C CCC C C C C C C C C C C C C C CC C C CC C CC C C C C C CC C C C C C C C C C C C C C C C C C C C C C C C C C C C C C C insect outbreaks and such are very correlated with weather C C C C C C C C CCC C CC C C C CCC C The differences between equilibrium density CC C Co C C C C C C Can C C C C C C C C C weather CCC CC CC CC C like hurricane bad storm cause density dependent C C C CC C C CC CC C C C C o Density dependent a certain amount of placesEquilibrium to hide ifdensity 10 candependent hide in a factors cave something and storm comes and all 10 hide then none killed if 90 can t make it to hiding than 90 are killed o Density independent storm comes through wipes out a certain percent no matter what 9 Should be swayed by the facts that isn t always the case Simple graphic model to illustrate how equilibrium density may be determined 4 Figure 14 2 5 Figure 14 3 POPULATION REGULATION Intraspecific Interspecific Density Independent Density Dependent Predation Competition 1 Weather 2 Pollution 1 Behavior Other Negative 2 Stress Interactions 3 Genetic Parasitism Allelopathy 4 Dispersal 6 o Buzzword way to categorize some of what we ve looked at o Population regulation There may be factors limiting not regulating the population o Four hypothesizes Intraspecific density dependent WFSC 403 613 CH 14 Population Behavior Regulation WFSC 403 613 CH 14 Population Stress Regulation Genetic Dispersal Environment A favorable Environment B Environment B Environment C unfavorable Density dependent actions actions Density dependent Density independent Density independent actions actions Environment A favorable Environment C Relative role of density dependent and density independent unfavorable processes in causing changes in population density under different types of environments After Huffaker and Relative role1964 of density dependent and density independent7 Messenger processes in causing changes in population density under different types of environments After Huffaker and 7 Messenger 1964 o Under what conditions expect density independent to be favored o Under what conditions you expect density dependent factors to be more important oDens Inity anDeunfavorable environment pendent Population Growth density independent actions are more important o In a favorable environment density dependent are more important Density Dependent Population Growth N N TIME G TIME dn dt G dn dt N Ne 8 N Ne 8 G growth curve Interaction of density independent and density dependent factors Ne di Ne di G independent and density dependent factors Interaction of density dn dt dn dt dn dt dn …