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:
“I am positive I have a soul; nor can all the books with which materialists have pester’d the world ever convince me of the contrary.”
—Laurence Sterne (1713–1768)
“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)