1. Species Selection. - Evolutionary Trends. - Clade Composition. - Species as Units of Selection. - Search for Evidence. - Conclusions. - References. - 2. Homology of the Bird Wing Skeleton: Embryological versus Paleontological Evidence. - The Development of the Bird Carpus and Metacarpus and the Identification of the Wing Skeletal Elements. - Cell Death Removes Anterior Mesenchyme from the Wing Bud. - Discussion. - Phylogenetic Implication of the 234 Theory. - Conclusions. - References. - 3. Interspecific Hybridization in the Genus Drosophila. - Subgenus Drosophila. - Subgenus Sophophora. - Subgenus Scaptodrosophila. - Summary of Results. - Discussion. - Summary Statement. - References. - 4. A Demographic Theory on the Evolution of Mating Systems As Exemplified by Birds. - Definitions of Mating Systems. - The Sex Ratio. - Natural Selection and Population Parameters. - Natural Selection and Life History Parameters. - A General Theory. - The Evolution of Polygyny. - The Evolution of Polyandry. - The Evolution of Monogamy. - The Evolution of Polygyny-Polyandry. - Discussion. - Summary. - Symbols. - References. - 5. Is There Ecomorphological Convergence among Mediterranean Bird Communities of Chile California and France?. - Research Goals. - Materials and Methods. - Results. - Discussion. - Conclusions. - Summary. - References. - 6. Arboreality: Is it Homologous in Metatherian and Eutherian Mammals?. - History of the Problem. - Methods. - Tarsal Transformation Sequences in the Mammalia. - Discussion. - Summary and Conclusions. - References. Language: English