Tangential question: Not a native speaker but wouldn't "only a few" make more sense than "a few"? The paper title emphasizes the lack of great variety, as does "only a few", but without any more context "a few [...] phenotypes" could also mean "more phenotypes than anticipated"?

'a few' is fairly neutral to expectations and more speaks to the absolute number - of which 4 is 'a few'.

If the author wanted to emphasize that this was fewer than expected, 'only a few' would have been appropriate - but this might not have been their intent.

(submitter)

The title is quite close to the 80 character limit. I started with "only a few" but had to cut "only" after I replaced dyadic with two player. "dyadic" seemed too obscure to use in a HN title.