What is the “Lazarus effect” and which animals have fallen victim to this phenomenon

Until recently, the Gould mouse (Pseudomys gouldii) was believed to be extinct, as it was last seen in 1895. However, recently a group of Australian scientists have rediscovered the species on a small island in Shark Bay, in the ocean country. After performing DNA analyzes on living individuals and comparing them to mice on display in museums, experts found that what until then was known as the Shark Bay mouse, was actually a Gouldian mouse. Thus, they concluded that the species did not go extinct, but only hid itself for over 125 years.

The mouse is cold-blooded, enters 85 and 115 millimeters, weighs between 30 and 60 grams, and has a life expectancy of only two years. According to a scientific study that compared a DNA sample from extinct rodents and their living relatives, the Gould mouse has DNA indistinguishable from that of Shark Bay, The species is native to the country, before the arrival of the colonizers in 1788.

Despite the fact that a population of 2,000 of these rodents was found on an island 42 kilometers from Shark Bay, researchers argued that it was not enough for a species to survive. That is why they were transferred to other islands between the months of May and November, during their breeding season, so that they could establish new colonies. The fact that they are on remote islands does not mean that the danger of extinction is disappearing, due to the large presence of their predators, such as wild and domestic cats.

This phenomenon, in which a species is assumed to be extinct and then reappears years later, is known as “Lazarus effect”, by a passage from the Bible in which Jesus Christ resuscitated Lazarus of Bethany four days after his death.

Specific, many species were victims of the Lazarus effect. Among the most striking are the Giant Fernandina Tortoise (Chelonoidis phantasticus) in the Galapagos Islands. In February 2019, researchers discovered a large turtle on Fernandina Island. According to an article by National Geographic, we calculate that the turtle found has over 100 years old and a specimen had not been seen since 1906, that’s why it was hidden for so long until it was considered extinct. Experts believe he is not the only living of his kind.

Another species is the bird cahow petrel (Pterodroma cahow) on Nonsuch Island, Bermuda. For 330 years they were considered extinct, until 1951 36 specimens were rediscovered. Today, after many years of nest management and pest control, the cahow petrel managed to significantly increase its number of breeding pairs: from 18 to 131. “This is an ongoing recovery and an example of an endangered species in a world and at a time when invasion and destruction of habitats is endangering more species than ever before,” said Jeremy Madeiros, head of the conservation, according to National Geographic.

The prehistoric fish coelacanth (Coelacanthiformes) was rescued in South Africa in 1938 by naturalist Marjorie Courtenay-Latimer- Scientists thought it was extinct, but two of the 90 documented species in the world still swim in the depths of the oceans. According to Caitlin Etherton of National Geographic, divers observed coelacanths in the coast of Tanzania, Kenya, Madagascar, Mozambique, Comoros, Sodwana Bay and Bunaken National Marine Park in Indonesia.

A study published last June in the scientific journal Cell claimed that these species could live up to 100 years, but did not reach maturity until 50 years. In addition, their gestation period is around five years, which makes them “Very vulnerable to natural and anthropogenic changes”, Based on research. Also, since they live around 200 meters deep, it is difficult to spot and study them.

Other notable species that suffered from the Lazarus effect were the Mongolian wild horse (a horse from the Caspian Sea) in Missouri and California; the porphyrio hochstetteri (calamón takahē) in New Zealand; the Phoboscincus bocourti and correlophus ciliatus (gecko crestado) in New Caledonia; the gastrotheca cornuta (cornupial frog) in the Chocó forest, Ecuador; and the catagonus wagneri (peccary quimilero, peccary taguá or Chaco) in Gran Chaco, Paraguay, Argentina and Bolivia.

Read on: