Evolution of Discontinuous Gas Exchange Cycles
Despite being well described, the mechanisms responsible for the evolution of discontinuous gas exchange cycles are largely unknown. Discontinuous gas exchange cycles have long been thought to be an adaptation to conserve water when living in a terrestrial environment (the hygric hypothesis). However, recent studies question the hygric hypothesis, and several alternative hypotheses have been proposed. For discontinuous gas exchange cycles to be considered adaptive, the origin and subsequent persistence of the trait must be demonstrated to be a result of natural selection.
Read more about this topic: Discontinuous Gas Exchange
Famous quotes containing the words evolution of, evolution, gas, exchange and/or cycles:
“Analyze theory-building how we will, we all must start in the middle. Our conceptual firsts are middle-sized, middle-distanced objects, and our introduction to them and to everything comes midway in the cultural evolution of the race.”
—Willard Van Orman Quine (b. 1908)
“What we think of as our sensitivity is only the higher evolution of terror in a poor dumb beast. We suffer for nothing. Our own death wish is our only real tragedy.”
—Mario Puzo (b. 1920)
“Papa died in the gas chamber,
slipping blue as an undressed minnow,
gulping in the shower to wash the Jew off him.”
—Anne Sexton (1928–1974)
“The social kiss is an exchange of insincerity between two combatants on the field of social advancement. It places hygiene before affection and condescension before all else.”
—Sunday Correspondent (London, Aug. 12, 1990)
“The stars which shone over Babylon and the stable in Bethlehem still shine as brightly over the Empire State Building and your front yard today. They perform their cycles with the same mathematical precision, and they will continue to affect each thing on earth, including man, as long as the earth exists.”
—Linda Goodman (b. 1929)