34 Quotes by Carl Sagan about evolution

  • Author Carl Sagan
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    And despite the insignificance of the instant we have so far occupied in cosmic time, it is clear that what happens on and near Earth at the beginning of thesecond cosmic year will depend very much on the scientific wisdom and the distinctly human sensitivity of mankind.

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  • Author Carl Sagan
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    Our probable ancestors, Homo erectus and Homo habilis -now extinct- are classified as of the same genus (Homo) but of different species, although no one (at least lately) has attempted the appropriate experiments to see if crosses of them with us would produce fertile offspring.

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  • Author Carl Sagan
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    Pliny suggested that the ostrich, then newly discovered, was the result of a cross between a giraffe and a gnat. (It would, I suppose, have to be a female giraffe and a male gnat.) In practice there must be many such crosses which have not beenattempted because of a certain understandable lack of motivation.

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  • Author Carl Sagan
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    For their surface area, insects weigh very little. A beetle, falling from a high altitude, quickly achieves terminal velocity: air resistance prevents it from falling very fast, and, after alighting on the ground, it will walk away, apparently none the worse for the experience… In contrast, human beings are characteristically maimed or killed by any fall of more than a few dozen feet: because of our size, we weigh too much for our surface area.

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  • Author Carl Sagan
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    The sleeping style of each organism is exquisitelyadapted to the ecology of the animal. It is conceivable that animals who are too stupid to be quiet on their own initiative are, during periods of high risk, immobilized by the implacable arm of sleep.

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