The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time. Which of the following is the most likely explanation for these data?
A) Humans and bats evolved by natural selection, and whales evolved by Lamarckian mechanisms.
B) Forelimb evolution was adaptive in people and bats, but not in whales.
C) Natural selection in an aquatic environment resulted in significant changes to whale forelimb anatomy.
D) Genes mutate faster in whales than in humans or bats.
E) Whales are not properly classified as mammals.
Structures of a cell.
Skeletal remains from the Sima de los Huesos, Sierra de Atapuerca, Spain.
The Upper Troposphere: Westerly Winds in the Upper Atmosphere
Abdominal vasculature and deep structures
Mutations in posterior Hox genes (HOXD13 in this case) in humans
Results of disrupted control of skeletal muscles