Passionate Productions for BBC ; produced for NOVA by Holt Productions, LLC ; WGBH Boston ; produced and directed by Jemima Harrison and Sarah Holt ; writer for the BBC, Jemima Harrison ; executive producer for the BBC, Richard Klein ; senior executive producer, Paula S. Apsell
a BBC Studios Natural History Unit production ; a co-production with BBC America, Tencent, WDR, France Televisions and CCTV9 ; a BBC Open University partnership ; executive producer, James Honeyborne ; series producer, Mark Brownlow ; producers, Miles Barton, Orla Doherty, Kathryn Jeffs, Will Ridgeon, John Ruthven, Jonathan Smith
A production of The Documentary Guild in association with WGBH Boston for Nova ; WGBH Educational Foundation ; Executive editor, William Grant ; executive producer, Paula S. Apsell ; written, produced and directed by Rob Whittlesey and Noel Buckner
a production of Thirteen and ArgoFilms in association with WNET.org for PBS ; written, produced and directed by Allison Argo ; executive producer, Fred Kaufman ; series producer, Bill Murphy