BIOB51H3 Lecture Notes - Lecture 3: Germination, Microevolution, Pitx1
14 Oct 2016
School
Department
Course
Professor
Document Summary
Darwin"s favorite domestic organism was the pigeon. He bred pigeons himself to learn the experts" techniques. To refine a breed of pigeon so that, for example, the birds" tail feathers fan more spectacularly, breeders employ artificial selection. They scrutinize their flocks and select the individuals with the most desirable traits. These the breeders cross to produce the next generation. If the desirable traits are passed from parents to offspring, then the next generation the progeny of the selected birds will show the desirable traits in a higher proportion than last year"s flock. The disparity in fruit size between wild versus domestic tomatoes is largely due to genetic differences. The gene encodes a protein made during early fruit development that represses cell division. The more of the protein a plant makes, the smaller its fruit. Changes in the nucleotide sequence in the fw2. 2 promoter the gene"s on-off switch alter the timing of production and the amount of repressor made.
