An Introduction to Quantitative Genetics

Summary …………………………………………………………………………………………………… 37 4.1 Introduction ………………………………………………………………………………………. 38 4.2 Phylogenetic Aspects of Causation ……………………………………………………… 38 4.2.1 Natural Selection and Genetic Architecture……………………………….. 38 4.2.2 Theoretical Background…………………………………………………………… 39 4.2.3 Examples ……………………………………………………………………………….. 43 4.3 Phenogenetic Aspects of Causation……………………………………………………… 43 4.3.1 The Correlational Approach: Brain Lesions and the Locality Assumption……………………………………………………. 43 4.3.2 Genetic Correlations ……………………………………………………………….. 44 4.3.3 Theoretical Background…………………………………………………………… 45 4.3.4 Examples ……………………………………………………………………………….. 48 4.3.4.1 Rearing Behavior in an Open Field and Hippocampal Mossy Fibers in Mice………………………………………………… 48 4.3.4.2 Nerve Conduction Velocity and IQ in Man………………….. 48 4.3.4.3 Localization of QTL………………………………………………….. 49 4.4 Some Common Misapplications………………………………………………………….. 49 4.5 Conclusion………………………………………………………………………………………… 51 Acknowledgments………………………………………………………………………………………. 52 References…………………………………………………………………………………………………. 52 Appendix…………………………………………………………………………………………………… 54 This chapter provides a brief overview of quantitative-genetic theory. Quantitative genetics provides important tools to help elucidate the genetic underpinnings of behavioral and neural phenotypes. This information can then provide substantial insights into the previous evolutionary history of a phenotype, as well as into brain-behavior relationships.