They are some similarities but the BBC's Civilisations and PBS's Civilizations are not the same. One is not an edit of the other, they were intentionally made differently.
Each episode of the BBC versions is hosted by one of historians Simon Schama, Mary Beard, or David Olusoga. They present and narrate their episodes, essentially delivering a personal lecture on their topic.
The PBS versions are narrated by actor Liev Schreiber, with Schama, Beard and Olusoga appearing as experts, alongside many other experts.
The BBC versions are about 5 minutes longer at around 60 minutes compared to 55 minutes for PBS.
Mary Beard was also surprised by the difference in being cut so much and especially by the disappearance of most of her actual argument.
PBS received many complaints and their public editor Madhulika Sikka (who "serves as an independent internal critic within PBS") wrote in Civilizations vs Civilisations:
I have seen a couple of episodes of both the BBC and PBS versions and, indeed, the presenters are not as prominent in the PBS version as they are on the BBC version, but they have not been removed completely. They appear more as a bit of a hybrid, part expert, part weaver of a narrative thread.
In the British version they do all the voice-over narration, too, and write their episodes. In the U.S. version the shows are narrated by actor Liev Schreiber and the narrative arc is quite different.
I exchanged emails with PBS Vice President of Programming and Development Bill Gardner and asked about the editorial process:
“The individual programs were developed side-by side by the producers, with treatments and drafts shared with both the BBC and PBS at various stages for feedback on the individual versions. At an early stage in development, the BBC decided to feature individual presenters, well-known in the UK, to appear in singular films. The BBC then steered their programs towards more individual ownership by these presenters, who were involved in the editorial shaping of their films alongside the directors and producers. PBS maintained the desire to have multiple voices and perspectives as well as stories particularly relevant to the US audience represented in the PBS versions and continued to work with the producers and directors to develop the PBS versions accordingly, making use of work being done on the BBC versions as well. The BBC also had access to development and material used in the PBS versions.”
There is a lot of material that is common to both versions, but unique material, too. Did they make one version and then decide what they needed for the other? No, says Gardner.
“The field directors were generally the same, as many film shoots were scheduled to capture material for both programs simultaneously, for shared or individual uses. PBS consulted with the field teams before departure to locations in order to discuss PBS specific content to capture, and at times requested scenes with participants planned for thematic inclusion in both versions be filmed or presented slightly differently for the PBS version. There were also dedicated shoots for the BBC and PBS versions respectively to capture independent material. In post production a dedicated editor and producer were assigned by the production company to edit the PBS versions, separate from the BBC versions. PBS did NOT view final BBC episodes and request changes in order to create the PBS versions. According to the producers, in some cases the PBS versions were actually completed prior to the BBC shows.”
So for those of you worried that Mary Beard has been unceremoniously disappeared from the PBS version because of her age or her looks, that is not the case. She and her fellow presenters do appear in the U.S. version, just in a very different way and not as much as in the British version for the reasons outlined by Mr. Gardner.
Of course, the question then arises, is one version better than the other? To that I would say, they are just different.
When Schama or Beard has “ownership,” they are presenting an arc and a thesis that leads them to an assessment about their themes. It doesn’t work quite the same way with the U.S. version and that will leave some disappointed.
They are definitely different narrative experiences. ...
There are things that work for an American audience that won’t work for a British audience and vice versa, or sometimes it's just a question of emphasis.
Both may well be follow-ups to the original 1969 Civilisation by Kenneth Clark, and may share some similarities, but it's misleading for both the BBC's Civilisations and PBS's Civilizations to be presented as being the same thing.