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.
Follicle and oocyte development in humans.
Spina bifida. (A) Spina bifica occulta; the vertebra is not complete, but there is no protrusion of
Anatomical and common names for the pectoral girdle and upper extremity.
Fossil remains of anatomically modern humans from the Czech Republic and from China (center crania)
Chemical structures of four amino acids
Structures of iron–sulfur clusters