<P> Ash Tyler (portrayed by Shazad Latif) is a Starfleet lieutenant and former prisoner of war . </P> <P> Latif was originally cast in the role of the Klingon Kol in December 2016, before being recast as Tyler at the end of April 2017 . Latif noted that Tyler's PTSD would be explored in the show as he attempts to return to his Starfleet life, calling Tyler "a very complex and painful and deep character ." The character explores these issues with different characters, including Lorca due to their shared military background, and Burnham with whom "there's a chemistry, a relationship". </P> <P> Paul Stamets (portrayed by Anthony Rapp) is a Science Officer specializing in astromycology (the study of fungi in space). </P> <P> Rapp was revealed to have been cast as Stamets in November 2016 . He was originally cast in a different, smaller role, but when discussing gay actors who could portray the character Stamets, the executive producers realized that Rapp was the actor they wanted to fill that role instead . He did not audition for either role . He is the first openly gay character in a Star Trek series, and the showrunners "wanted to roll out that character's sexuality the way people would roll out their sexuality in life". Rapp noted that Hikaru Sulu was portrayed as gay in the film Star Trek Beyond, calling that "a nice nod . But in this case, we actually get to see me with my partner in conversation, in our living quarters, you get to see our relationship over time, treated as any other relationship would be treated". </P>

Who plays the science officer in star trek discovery