BIO 1130 Lecture Notes - Lecture 4: Melanism, Null Hypothesis, Gene Pool

• School: University of Ottawa
• Department: Biology
• Course: BIO 1130
• Professor: Jon Houseman

Document Summary

How we know its occurring is it"s a change in allele frequency in a population. Gene pool change to get an advantage over generations can confirm natural selection has occurred. Observation 1: original museum collections had all white peppered moths and 1900 traps collected. Hypothesis 1: fitness decreased when the moths that were more visible against the background colour of the trees. Null hypothesis 1 (alternate explanation): fitness remains the same and is not affected by the background. Hypothesis 2: the dark colour of the trees has changed. Null hypothesis 2: the bark colour of the tress has not changed. Experiment 1: artificially rear light and dark morphs and place on tree and observe survival (fitness) Black moths came back (a lot) while white ones came back (very little)*they were being removed from population* Experiment 2: locate light and dark coloured trees. Then did same experiment 1 the black moths disappeared while white ones came back.