The Mariposans were a group of Humans who inhabited the Mariposa colony in the Ficus sector. They founded their colony in the mid-22nd century, on the planet where their ship, the SS Mariposa, crash-landed. Only five colonists (two females, three males) survived the crash-landing. Because they were technologically-savvy scientists, the Mariposans turned to cloning to perpetuate their culture.
The existence of the Mariposans was revealed to the Federation in 2365 by the nearby Bringloidi, who were also descended from Mariposa colonists and had recently been evacuated by the USS Enterprise-D. By this time, the Mariposans had begun to suffer from replicative fading and were facing extinction, unless new genetic material could be obtained. To this end, the Mariposans attempted to create clones of the Enterprise crew. However, the Enterprise crew members considered this a breach of their personal rights and terminated the clones.
As a solution, Captain Jean-Luc Picard proposed merging the Mariposan population with the Bringloidi. Initially the Mariposans, who after centuries of non-sexual reproduction had begun to consider physical contact abhorrent, refused. However, once it became clear that such a compromise might be the only hope for their survival, Mariposan prime minister Wilson Granger agreed. (TNG: "Up The Long Ladder")