Facebook will no longer employ humans to write descriptions for items in its Trending section, which attracted controversy over allegations of political bias in May. Topics appearing in the Trending section will now appear solely as a short phrase or single word, with an indication of the number of people discussing it on the social network.

Quartz confirmed from multiple sources that Facebook has laid off the entire editorial staff on the Trending team—15-18 workers contracted through a third party. The Trending team will now be staffed entirely by engineers, who will work to check that topics and articles surfaced by the algorithms are newsworthy.

Facebook maintains that trending items have always been selected by algorithms; the former editorial staff was only responsible for writing the story descriptions seen in the Trending section, according to the company. This was disputed by former contractors hired by the tech giant who told Gizmodo in May that they were instructed to manually add some stories by hand. Stories on conservative topics were routinely excluded from the Trending list even though they were popular among Facebook users, Gizmodo reported.

Facebook investigated the claims and said it found “no evidence of systematic bias,” but that hasn’t stopped the company from making changes to the feature.

A new group of humans will still be involved with Trending, although they’ll be asked to focus on correcting the algorithm’s mistakes, like preventing mundane or repetitive stories from appearing as news, according to a Facebook blog post. The retooled Trending feature will now automatically pull excerpts from news articles, a feature that may force Facebook to compensate news publishers in the European Union in the future, under proposed new rules from the European commission.

According to sources, the Trending team’s editorial staff were alerted at 4pm that they were being fired—as the news of Facebook’s switch to algorithms first broke—and were asked to leave the building by 5pm. The contractors (all of whom were at the company less than 1.5 years) were given severance equal to pay through September 1, plus two weeks, sources say.

However, removing human writers from Trending doesn’t necessarily eliminate bias. Human bias can be embedded into algorithms, and extremely difficult to strip out. That’s one of the conclusions from a study (pdf) of a popular algorithm used for processing language from Princeton University and the University of Bath released as a draft yesterday (Aug. 25). It’s currently under review for publication in a journal.

“Language itself contains recoverable and accurate imprints of our historic biases,” the authors write. “Whether these are morally neutral as towards insects or flowers, problematic as towards race or gender, or even simply veridical, reflecting the status quo for the distribution of gender with respect to careers or first names.”

Facebook’s increased reliance on automation reflects the company’s growing faith in machine intelligence. But even machines may fail to overcome some the most fundamental problems that humans face, like operating fairly in the face of embedded bias.

As Gizmodo reported in May, Facebook’s primary reason for hiring human curators appeared to be to train their algorithms in what was newsworthy—and so it’s very likely their human biases were recorded and potentially amplified by the AI.