Evolution of Swimming
Swimming evolved a number of times in unrelated lineages, and the evolutionary pressures leading to its adoption are unknown. Supposed jellyfish fossils occur in the Ediacaran, but the first free-swimming animals appear in the Early to Middle Cambrian. These are mostly related to the arthropods, and include the Anomalocaridids, which swam by means of lateral lobes in a fashion reminiscent of today's cuttlefish. Cephalopods joined the ranks of the nekton in the late Cambrian, and chordates were probably swimming from the Early Cambrian. Many terrestrial animals retain some capacity to swim, however some have returned to the water and developed the capacities for aquatic locomotion.
Read more about this topic: Aquatic Locomotion
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“The evolution of a highly destined society must be moral; it must run in the grooves of the celestial wheels.”
—Ralph Waldo Emerson (1803–1882)
“The evolution of a highly destined society must be moral; it must run in the grooves of the celestial wheels.”
—Ralph Waldo Emerson (1803–1882)
“Awareness of having better things to do with their lives is the secret to immunizing our children against false values—whether presented on television or in “real life.” The child who finds fulfillment in music or reading or cooking or swimming or writing or drawing is not as easily convinced that he needs recognition or power or some “high” to feel worthwhile.”
—Polly Berrien Berends (20th century)