In the eastern part of the Pacific Ocean, near the equator, 973 kilometers from the west coast of South America, sits the Galapagos Islands.
The Galapagos Archipelago consists of 7 large islands, 23 small islands, and more than 50 rocks, of which Isabella Island is the largest and Santa Cruz Island has the largest population. The archipelago, consisting entirely of volcanic piles and lava, runs through the north by the equator, and has a cool and extremely arid climate due to the influence of the peruvian cold current.
These islands are home to exotic animals such as galapagos land iguanas and Galapagos penguins, and many of the flora and fauna are unique to the world.
<h1 class="pgc-h-arrow-right" > Galapagos tortoise</h1>
The island's best-known animal is probably the Galapagos tortoise, one of the largest tortoises in existence. Endemic to the Galapagos Islands in Ecuador, adult tortoises are 1.5 m (4.9 ft) long, weigh an average of 175 kg, record 400 kg (880 lbs) and have a life expectancy of more than 100 years in the wild, making it one of the longest-lived species in the animal kingdom.
Galapagos tortoises are herbivores whose diet includes cacti, grass, leaves, mosses and berries. A turtle eats an average of 32-36 kilograms (70-80 pounds) of food per day, but consumes less nutrients because of the lower efficiency of the digestive system.
Galapagos tortoises get most of their water from the dew and sap of the plant, so they can stay out of water for a long time. They can also endure up to 18 months without eating or drinking; when they are thirsty, they can drink water at a rate that is both large and fast, and stored in their bladder and heart, so that they do not have to drink water for a long time. On arid islands, tortoises lick the dew from boulders in the early morning, so many of the island's rocks have formed rock depressions caused by such behavior for many generations.
There are currently nine subspecies of Galapagos tortoises (12 in history, three of which have become extinct in modern times): Galapagos tortoises in Pinzon Island, Galapagos tortoises on Espanola Island, Galapagos Tortoises on Frélianna Island, Galapagos Tortoises on Santa Cruz Island, Galapagos Tortoise in Southern Isabella Island, Galapagos Tortoise on Pinta Island, Galapagos Tortoise on Wolf Volcano, Galapagos Tortoise on San Cristobal Island and Galapagos Tortoise on San Tejago Island.
During the Age of Discovery, the Galapagos Islands became a whaling base, and many pirates used it as a transit point, killing and capturing thousands of Galapagos tortoises for food. Tortoises can stay on board as a means of providing fresh protein, as these animals can survive for months without any food or lack of water on board. This move led to a massive reduction or even extinction of Galapagos tortoises. At the beginning of the 16th century, there were about 250,000 Galapagos tortoises, but now only 19,000 remain.
Among these subspecies that currently exist, the Galapagos tortoise on Espanola Island can be said to be in danger of extinction, and it was not until the appearance of the centenarian turtle Diego that the population was saved.
< h1 class= "pgc-h-arrow-right" > Diego save the population</h1>
Before Diego arrived, the researchers landed on Espanola Island to search for the island's tortoise population to see if the island's tortoise population had survived, and initially the researchers did not have larvae of the turtles, thinking that the island's tortoises were extinct.
Only 14 adults, 2 males, and 12 females remain on the island, but due to the slow walking speed, they did not meet each other and did not breed successfully for nearly 30 years, which is why there are no juveniles on the island.
Since there are still males, the researchers quickly transported these adult turtles to the Tortoise Breeding Center in Santa Cruz to help them breed, but the 2 males were not very powerful, which made the researchers very sad.
At this time, the researchers found that the Darwin Institute also had a Galapagos tortoise on Espanola Island, which was Diego. He was taken away from home in 1933 while allan Hancock was on a scientific voyage on his yacht. On August 8, 1977, after 40 years of "displacement", Diego returned to the Galapagos Islands and met his companions.
Weighing 82 kilograms and measuring 90 centimeters long, Diego is the oldest male tortoise on the island, but is more powerful than the other two male tortoises in breeding offspring.
For decades, he has always had a fanatical obsession with Papa, and has successfully bred more than 800 offspring with hundreds of female turtles, and nearly 40% of the island's newborn animals are his offspring, and all the tortoises basically flow his blood.
Thanks to its efforts, the entire Espanola subspecies was saved from 14 to 2,000. Then many people are curious, isn't there only 12 female turtles in total? Where are the hundreds of female turtles popping up? This is not simple, after all, the mother turtle will also give birth to a small female turtle...
In 2020, after 43 years of hard work, the centenarian turtle finally retired, and after retirement, it will return to the wild on the island of Espagnola.
Turtle conservation experts in Galapagos National Park praised Diego as an active male breeder who has made a significant contribution to the archipelago's population.
< h1 class="pgc-h-arrow-right" > whether there will be genetic problems</h1>
But some scientists worry because the Espanola subspecies are mostly descendants of Diego, which also means that the population is too genetically diverse, and that population is vulnerable to some dangerous disease or environmental changes caused by climate change.
But Linda Cayo, a scientist at the Galapagos Natural Resources Management Council, disputed, saying the Galapagos island species had a long history of being massively destroyed to the point where only a few survived and then recovered in numbers without incident — such as a group of giant tortoises that chose to live in the caldera of a volcano. After the volcano erupted 100,000 years ago, the number of these tortoises gradually rebounded and returned to the caldera.
For now, the Galapagos tortoise on Espanola Island will experience a bottleneck effect, which refers to the collapse of large groups during the process of biological generational change, resulting in a serious loss of individual number and genetic variation within the population.
As the population experiences a bottleneck and then expands to its original size, the frequency of the median gene in the population fluctuates, an effect known as the bottleneck effect. Populations may rapidly re-expand to the number of individuals in the original population after experiencing bottlenecks, but the level of genetic variation in the population cannot be restored to the original level until the genetic mutation or gene flow is restored to the original population's genetic variation level.
In any case, extinction means never to be reborn, and the Galapagos tortoise on Espanola island at least remains on Earth. As for the future, we will also continue to explore a path to revive their populations.