(FILES) This handout pictured taken on October 18, 2017, and released by the Mexican Secretary of Environment and Natural Resources (Semarnat) shows scientists with a six-month-old vaquita marina porpoise calf -- the first ever caught as part of a bold program to save the critically endangered species, at the sea of Baja California State, Mexico. - Vaquita porpoises are on the edge of extinction, with just 10 left in their sole habibat within Mexico's Gulf of California. However, a new study in Science on Thursday offers some hope: the world's rarest marine mammals aren't doomed by a lack of genetic diversity, and can recover if illegal "gillnet" fishing ceases immediately. "We're trying to push back on this idea that there's no hope, that nothing we do could save them at this point. It's just not an accurate assumption," lead author Jacqueline Robinson of the University of California San Francisco told AFP. Porpoises are closely related to dolphins, and share many things in common including great intelligence. The vaquita, whose name means "little cow" in Spanish, measures four to five feet in length, making it the smallest of all cetaceans. (Photo by Semarnat / AFP) / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / SEMARNAT" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS / TO GO WITH AFP STORY by Lucie AUBOURG, "Inbreeding won't doom the last of the vaquitas, but fishing might: study"