But it had no plans to harm the finch The finch had seen a tick crawling up the tortoise's leg Before the giant creature took another step the bird gobbled up the pest The finch had done Not Extinct After All The Floreana species of Galápagos tortoise appeared to have gone extinct in the 1800s But a 2011 study offered new information The study revealed that 84 of the 1 600 animals studied had DNA from the Floreana tortoise DNA is a material found in cells that contains information about how a species will look and behave The tortoises were a mix of different species But it meant the Floreana species was not completely lost It is also possible that pure members of the species are still out there Scientists hope to discover them the tortoise a favor by removing the tick And it had found its own breakfast in the process The finch distracted the tortoise from munching on the vine Instead the tortoise remained still under the morning sun There was
no need for the tortoise to rush There was always grass nearby Lucky to Be Alive Tortoises have roamed the Galápagos Islands for centuries These islands form an archipelago off the coast of Ecuador The Galápagos tortoise caught the eye of English naturalist Charles Darwin Darwin visited the Galápagos Islands in 1835 The tortoise is believed to have played a big role in the development of Darwin's theory of evolution Over time 14 species have evolved from the original Galápagos tortoises This is a process called adaptive radiation Some species are specific to a single island But some islands have more than one species These species are part of the same genus Chelonoidis A genus is a category that contains species with similar characteristics Approximately 250 000 of these reptiles lived on the Galápagos Islands during the 1600s Over time both people and other animals threatened the
Darwin's studies of the tortoises and the islands other species played a key role in his work on evolution tortoises By the 1970s only approximately 3 000 of them remained Some of the largest threats to Galápagos tortoises were whalers fur sealers and pirates Starting in the 1600s these people quickly learned that the tortoises were a handy source of food
The animals could go long periods without eating or drinking Sailors could put the tortoises on their ships and kill them when they needed food Other threats harmed the tortoises too Visitors brought other animals to the islands Both Darwin's Discoveries When he visited the Galápagos Islands Darwin noticed differences in the shells of these large reptiles Saddleback tortoises have shells that rise in the front like saddles This feature allows them to extend their necks higher This helps them eat tall plants Dome shaped tortoises do not have this feature Since these tortoises eat food off the ground they do not need the rising shells The more Darwin studied the tortoises the better he understood how they had adapted to their environments goats and rats caused major problems for the Galápagos tortoise Goats competed with tortoises for native plants This threatened the tortoises food source Rats ate tortoise hatchlings threatening the population
