xii I Contents 



Continuous Variation 52 

 Summary 54 

 References 55 



Chapter 4 | Development 56 



Growth and Homeostasis 57 



Life Cycles 61 



Differentiation and Morphogenesis 62 



Modification of the Developmental System 66 



Summary 67 



References 68 



PART 2 ! POPULATIONS: 

 PROPERTIES 



Chapter 5 | Populations 72 



Individuals and Colonies 73 

 Spatial Distribution 75 

 Ecological Distribution 76 

 Structure 79 

 Numbers of Individuals 80 

 Environment 82 

 Communities 86 

 Summary 87 

 References 88 



Chapter 6 | The Theory of Population Genetics 90 



Mendelian Populations 91 



Panmixis 91 



Gene Pool and Gene Frequency 92 



Hardy-Weinberg Law 93 

 Population Size 95 



Effective Breeding Size 96 



Genetic Drift 97 



Decay of Variability 98 



Loss of Mutations 100 

 Mutation 101 



