BIOL 121 Lecture Notes - Lecture 28: Peppered Moth, Medium Ground Finch, Bernard Kettlewell
Document Summary
Industrial melanism: a phenomenon that affected over 70 species of moths in england, best studied example = the peppered moth, biston betularia, two forms: light colored & dark colored (melanic) **prior to 1800, most individuals of this species were light coloured. First hypothesis: blackness in moths caused directly by pollutants derived from smoke and industrial process, acting to alter the metabolism of the insects. Later: bowater (1914: genetic basis for colour forms, melanic form was dominant (in effect, several alleles. Second hypothesis: selective predation by insectivorous birds, kettlewell tested his hypothesis by conducting field experiments/observation. Example 3: beak size in galapagos finches: since 1973, peter & rosemary grant studies process of natural selection in finches, daphne major, small island (0. 34 km2, 8 km to nearest island. Hypothesis: dry conditions produce large seeds and may result in larger beaks in succeeding generations of.
