Positive selection may refer to:
- Positive selection as an event during thymocyte maturation
- Directional selection, a particular mode or mechanism of natural selection.
Famous quotes containing the words positive and/or selection:
“It is easy and dismally enervating to think of opposition as merely perverse or actually evil—far more invigorating to see it as essential for honing the mind, and as a positive good in itself. For the day that moral issues cease to be fought over is the day the word “human” disappears from the race.”
—Jill Tweedie (b. 1936)
“The books for young people say a great deal about the selection of Friends; it is because they really have nothing to say about Friends. They mean associates and confidants merely.”
—Henry David Thoreau (1817–1862)