Yersa was a 23rd century Argelian woman, an exobiologist in the 2260s decade.
Biography[]
In the year 2267, she traveled to Sherman's Planet on a freighter carrying an emergency replenishment of quadrotriticale. After assisting Cyrano Jones in his investigations into tribble reproduction, she transferred to space station Deep Space Station K-7, and from there began to conduct field studies on planet Iota Geminorum IV. Her research discovered how tribbles were affected by their natural environment, in particular their reproduction rate. (TOS - Strange New Worlds I short story: "The Last Tribble")