In this case without requiring humans to be involved.
"Critics of evolution often fall back on the maxim that no one has ever seen one species split into two. While that's clearly a straw man, because most speciation takes far longer than our lifespan to occur, it's also not true. We have seen species split, and we continue to see species diverging every day.
"For example, there were the two new species of American goatsbeards (or salsifies, genus Tragopogon) that sprung into existence in the past century. In the early 1900s, three species of these wildflowers - the western salsify (T. dubius), the meadow salsify (T. pratensis), and the oyster plant (T. porrifolius) - were introduced to the United States from Europe. As their populations expanded, the species interacted, often producing sterile hybrids. But by the 1950s, scientists realized that there were two new variations of goatsbeard growing. While they looked like hybrids, they weren't sterile. They were perfectly capable of reproducing with their own kind but not with any of the original three species - the classic definition of a new species."
https://blogs.scientificamerican.com/science-sushi/evolution-watching-speciation-occur-observations/