Shortages of women, minorities and conservatives are shaping digital content in ways you can't see.

We’ve learned a lot this month about how Facebook picks its trending topics: A team of curators monitors lists of stories organized by an algorithm, boosting, banning and remixing headlines in real time. Those curators may or may not suppress conservative news, something that’s sparked questions about how the social network shapes the content users see.

Facebook is, of course, free to decide what to publish, but a public conversation about its methods is still a good thing, especially if that discussion focuses on more than political leanings.

Anyone troubled by the notion of bias at Facebook, including the conservative leaders who met with CEO Mark Zuckerberg on Wednesday, should also be upset by its lack of diversity and the homogeneous workforces of many tech companies. These cornerstones of the social web play significant roles in determining what is and isn’t news. If the default worker is white, male, straight and liberal, that increases the risk that journalism’s future will repeat the mistakes of its past.