3 - 1 © 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Lecture # 3 GENETICS and EVOLUTION

3 - 2 © 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour The Development of Evolutionary Theory  Charles Darwin and origin of species  a species’ behaviour (and physical make-up) is due to the constant (natural occurring) reproductive pressure to propagate the species ie giraffes, sickle cell anemia, bacterial antibiotic resistance

3 - 3 © 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour A Couple of (important) definitions: Genotype: the collection of genes which define the biological potential of an organism Phenotype: the actual behavioural or physical state that results from gene expression and other outside influences

3 - 4 © 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Biological evolution: alterations in the the phenotype of an organism due to changes in the genetic make-up (genotype). HOW DOES THIS WORK?

3 - 5 © 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Natural Selection and Evolution  Artificial Selection – A procedure in which animals are deliberately mated to produce offspring that possess particularly desirable characteristics.  Natural Selection – The consequence of the fact that organisms reproduce differentially, which is caused by behavioural differences among them. Within any given population, some animals – the survivors – will produce more offspring than will other animals.

3 - 6 © 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour The Development of Evolutionary Theory Varieties of pigeons believed to have been produced through artificial selection: (1) Wild rock pigeon (ancestor) (b) Blue grizzle frillback (c) English pouter (d) Indian Fantail F 3.1

3 - 7 © 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Natural Selection and Evolution F 3.2

3 - 8 © 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour SO…why aren’t there wolves who can run as fast as a cheetah? There are a number of factors… Genetic potential i.e. biomechanics Confounding disadvantages inability to change direction quickly reduces hunting success

3 - 9 © 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour  Reproductive success – the number of viable offspring an individual produces relative to the number of viable offspring produced by other members of the same species  Variation – the differences found across individuals of any given species in terms of their genetic, biological, and psychological characteristics Natural Selection and Evolution

© 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Environment can play an important role. Consider the role of intereuterine sex hormones Adaptive modification: alteration in behaviour due to an outside source of variabilty. Are the genes you are “dealt” the only factor in your reproductive success ? NO!

© 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Heredity and Genetics The structure and composition of DNA. Genes serve as “recipes” for the synthesis of proteins and enzymes. F 3.4

© 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour The Flow of Genetic Information DNA Protein translation FUNCTIONFUNCTION transcription UCGAUCGA RNA Enviromental factors

© 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Heredity and Genetics

© 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Heredity and Genetics The determination of sex. The sex of human offspring depends on whether the sperm that fertilizes the ovum caries an X or a Y chromosome. F 3.5

© 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Heredity and Genetics F 3.6

© 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Sociobiology  Sociobiology – the study of the genetic bases of social behaviour  Parental Investment – the resources that a parent spends in procreations and feeding, nurturing, and protecting of offspring  Sexual Selection – s election of traits specific to sex, such as body size or particular patterns of behaviour  Reproductive Strategies – different systems of mating and rearing offspring, including monogamy, polygyny, polyandry, and polygynandry

© 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Sociobiology  Monogamy – t he mating of one female and one male  Polygyny – the mating of one male with more than one female  Polyandry – the mating of one female with more than one male  Polygynandry – the mating of several females with several males

© 2000 Pearson Education Canada Inc.,Toronto, Ontario Evolution, Heredity, and Behaviour Reproductive Strategies F 3.8