Federally funded research grants now require studies to include both males and females of the species being studied to receive and continue funding.

“It's a recent switch, but there's a stipulation in every federally funded grant that both sexes, we don't refer to gender in scientific studies, unless it's a study of gender, per se. We refer to sex, meaning biological sex, so that there's a stipulation, that in order to receive and continue to receive funding, you have to do a studies on both males and females of that species, including humans.”