17 BIOL 1001 Midterm Clare W2023 Group 16 Whales evolved from walking land dwelling ancestors Over evolutionary time the descendants of those ancestors gradually reduced the size of their hips and back limbs Which of the following is the best explanation of how natural selection can account for this loss C A The hips and back limbs became smaller because their presence made no difference to the fitness of individuals B The hips and back limbs stopped being used when whales swam As a result of that disuse they became smaller and eventually disappeared C The hips and back limbs of individual whales became smaller in response to the need to pursue fish and other marine prey D The ancestors of whales experienced harmful mutations which caused the loss of their hips and back limbs E Among the whales and their recent ancestors larger hip and back limb size reduced reproductive success GBDECAF a FAB CE D b ABCED BEDC d Above are 4 phylogenetic trees Which of the following statements best describes them A Trees a b and d show the same relationships c is different B All four trees show the exact same relationships C All four trees show completely different evolutionary relationships D Trees a c and d show the same relationships b is different E Trees a and d show the same relationships b and c are different In stabilizing selection we see a change in the distribution of a trait that is characterized by A A shift towards whichever allele is rare The loss of individuals with an average phenotype An increase or decrease in the mean of a population trait The maintenance of multiple discrete phenotypes The loss of extremes of a trait in a population