Lonesome George: Galapagos tortoise 'was not the last of his kind' The results means that there could be "additional hybrids on the Wolf Volcano, and even individuals on Pinta that could be pure," the statement read. Experts estimate there were once some 300,000 giant tortoises on the remote Pacific archipelago, but the species was decimated by whalers and pirates in the 18th and 19th century, who took them aboard their ships as fresh food and introduced new predators. Today there are about between 30,000 and 40,000 tortoises of 10 different species on the Galapagos. The Pinta and Floreana island tortoise, and other hybrids, were probably taken to Isabella Island in the 18th century by sailors who threw them overboard when they no longer needed the animals as food, the statement read. Park authorities have known since 2008 of the existence of hybrids with Pinta Island tortoise genes, but National Park biologist Washington Tapia said in June that he believed there were not enough to bring back Lonesome George's species. A more complete report on the find will be published in an upcoming issue of the journal Biological Conservation. The Galapagos became famous when Charles Darwin visited in 1835 to conduct landmark research that led to his revolutionary theories on evolution. The archipelago has been a Unesco World Heritage Site since 1978 for the unique plant and animal life found both on its land and in the surrounding sea. In 2007, the organization declared the island chain's environment endangered due to the increase in tourism and the introduction of invasive species.