Thursday, March12th2015 Module 3- EcologyAnimal Behaviour I: Nature vs. NurtureThe “Selfish”(or ‘immortal’) GeneRichard Dawkins, 1976 – book.General idea: DNA seeks to replicate itself. Organisms are simply vehicles for gene replication, which is achieved through reproduction.Species that do not reproduce would cease to exist. Such as extinction Therefore, reproduction is the basic requirement for the continuation of life and diversity at both genetic and species scales.Individuals who do not reproduce drop out of the gene pool biologically speaking, they contribute nothing to their species.Natural selection operates on the phenotypes of individuals; those individuals with the most successful phenotypes have the most offspring.More offspring = more replication = life WIN!So the meaning of life is.. !… High Relative Fitness. In a biological sense, this means that those individuals who produce the most offspring who survive to sexual maturity themselves will contribute the most genes to the next generation, relative to other individuals of the same population / species (conspecifics). Fitness is only compared relative to individuals of the same species, and usually in the same population. Despite the definition, we often measure relative fitness in terms of the number of offspring; we don’t usually track them to maturity. So the Meaning of Life (biologically speaking!) is…. Have Lots of Healthy Babies!The Study of Animal Behaviour=ethology1.What is the mechanistic basis of the behaviour, including chemical, anatomical, physiologicalmechanisms? Maternal stress can influence health and behaviour of offspring in their lifetime2.How does development of an animal influence behaviour?3.What is the evolutionary history of the behaviour?4.How does behaviour contribute to survival and reproduction (fitness)?
Organismal Behaviour Must Ultimately Maximize Reproductive Fitness Through…1.Survival2.Growth & Maintenance, can not reproduce until you are a certain size or if you can smaller mature adults have less or unhealthier offspring 3.Defense, defending territory which holds resources or mates or defending your own life 4.Mating5.Parental Care, not all organisms do this, some do once they are fertilized or maybe into adulthoodOrganisms are always under pressure to obtain and maximize limiting resourcesLimiting resourcesare factors in the environment, which are limited in availability, but necessary for an organism’s survival, growth, and/or reproductive success. Basic examples:1.Food2.Water 3.Space (nesting, foraging, hiding, etc.) 4.Mates 5.TIME, every organism has a lifespan, within that there is a limited time within which you can grow and reproduce, also a sessional effect, as an organism you are limited to seasons, 7