As a consequence, geneticists described evolution simply as a change in gene frequencies in populations, totally ignoring the fact that evolution consists of the two simultaneous but quite separate phenomena of adaptation and diversification.
— Ernst Mayr

Every European visitor to the United States is struck by the comparative rarity of what he would call a face, by the frequency of men and women who look like elderly babies. If he stays in the States for any length of time, he will learn that this cannot be put down to a lack of sensibility -- the American feels the joys and sufferings of human life as keenly as anybody else. The only plausible explanation I can find lies in his different attitude to the past. To have a face, in the European sense of the word, it would seem that one must not only enjoy and suffer but also desire to preserve the memory of even the most humiliating and unpleasant experiences of the past.
W. H. Auden frequency quote

Frequency quotes
Picture quote about Frequency

The simplest single-celled organism oscillates to a number of different frequencies, at the atomic, molecular, sub-cellular, and cellular levels. Microscopic movies of these organisms are striking for the ceaseless, rhythmic pulsation that is revealed. In an organism as complex as a human being, the frequencies of oscillation and the interactions between those frequencies are multitudinous.
— George Leonard

Though most of us don't hunt, our eyes are still the great monopolists of our senses. To taste or touch your enemy or your food, you have to be unnervingly close to it. To smell or hear it, you can risk being further off. But vision can rush through the fields and up the mountains, travel across time, country, and parsecs of outer space, and collect bushel baskets of information as it goes. Animals that hear high frequencies better than we do
— Diane Ackerman

For a smart material to be able to send out a more complex signal it needs to be nonlinear. If you hit a tuning fork twice as hard it will ring twice as loud but still at the same frequency. That's a linear response. If you hit a person twice as hard they're unlikely just to shout twice as loud. That property lets you learn more about the person than the tuning fork.
— frequency quotation by Neil Gershenfeld