The formation of Botryllus multichimeras sets the 'group level' (the assemblage of several genotypes into one unified entity) as the key level at which natural selection acts.

The school is not in a position to provide day-care after 4:00 pm.

Two important functions in nonassociative ring theory are the commutator and associator which, for elements a, b, c in a ring are defined respectively by [a, b] = ab − ba and [a, b, c] = a(bc) − (ab)c.

He had a bum trip on that mescaline.