BILD 3 Lecture 4: 1-23-17 lecture notes 4
Document Summary
Thought of inheritance as a blending of traits of parents. Blending would tend to eliminate differences among individuals, and dilute advantageous traits. Breeding experiments showed that variation could be preserved across generations and selected traits could be enhanced. This refuted the blending hypothesis but there was nothing to replace it. Refuted the idea of blending inheritance because white and red forms could be recovered from crosses among pink flowers. Brought darwin"s ideas on natural selection together with genetics. Provided a description of how the frequencies of genes in population change due to various forces. Eye color, blood type, flower color in mendel"s peas. Height or weight of individuals, bill size in birds, seed weight. Variation due to the combined effects of many genes. Flower color is a qualitative trait with three phenotypic classes: red, pink, and white. Individual organisms do not evolve in the darwinian sense. Natural selection acts on genes or individuals but populations evolve.
