Question

Manatees and seals both share some phenotypic similarities that are adaptations to an aquatic environment. However, seals evolved from a bearlike carnivore and manatees evolved from a hoofed mammal. This example shows that __________.
a. evolution is not always unidirectional.
b. evolution can occur rapidly for one species while the other species stays relatively unchanged.
c. similarity is a good predictor of how long it has been since two species shared a common ancestor.
d. evolution is not always divergent.

Answer 1

They are about as different as a leopard and a cow.

Meaning both are mammals of roughly similar size, and sharing a vaguely similar habitat. That’s the end of similarities.

Seals are carnivorous and manatees are plant eaters, and taxonomically they are in different orders. Seals spend much of the time on land, while manatees are completely aquatic. Seals have thick layer of fat and are adapted to Arctic water, while manatees, despite their roly-poly appearance, have almost no fat and do not handle cold water well at all. Here is the closest a manatee ever gets to an iceberg.

Manatees and seals both share some phenotypic similarities that are adaptations to an aquatic environment. However, seals evolved from a bearlike carnivore and manatees evolved from a hoofed mammal. This example shows that Evolution is not always divergent.