The difference in average tadpole body mass was small between the low and medium population density conditions and substantially larger between the low and high population density conditions.

Tadpoles in the low and medium population density conditions had substantially lower average bufadienolide concentrations but had greater average body masses than those in the high population density condition.

Tadpoles in the high population density condition displayed a relatively modest increase in the average amount of bufadienolide but roughly double the average bufadienolide concentration compared to those in the low population density condition.

Tadpoles produced approximately the same number of different bufadienolide toxins per individual across the population density conditions, but average tadpole body mass decreased as population density increased.

Students tend to be more enthusiastic about rap music than they are about hip-hop music.

Students who are highly interested in social justice issues typically don't sign up for courses that incorporate hip-hop and rap music.

Educators report that they enjoy teaching courses that involve hip-hop and rap music more than teaching courses that don't.

Courses that incorporate hip-hop and rap music are among the courses with the highest enrollment and attendance rates.

face-like stimuli are likely perceived as harmless by newborns of social species that practice parental care but as threatening by newborns of solitary species without parental care.

researchers should not assume that an innate attraction to face-like stimuli is necessarily an adaptation related to social interaction or parental care.

researchers can assume that the attraction to face-like stimuli that is seen in social species that practice parental care is learned rather than innate.

newly hatched Testudo tortoises show a stronger preference for face-like stimuli than adult Testudo tortoises do.