“This mockery of science has to stop. It just has to stop. These are people who just don’t understand science at all,” Brennan said Monday during a phone interview.

The federal grant that started this controversy is tiny, at least among the big numbers of the federal budget. Brennan’s funding equals 0.0000004 percent of this year’s total spending. The National Science Foundation, which gave her the grant in 2009, got $5.9 billion for all its research this year.

But these debates are rarely about the money. They are about moral choices embedded in the federal budget. As in: If nobody else will provide funding to study the secrets of duck genitals, does the government have a moral obligation to do it?

The NSF says yes. A civilized culture needs people studying things that might never make anybody any money. One of Brennan’s collaborators, for instance, studies why bluebirds are blue. What he’s found could change the way paint is made.

But other people wonder whether a civilized culture could survive without knowing the secrets of duck sex.