Evidence indicates a Galapagos tortoise thought extinct since the mid-1800s may still be around.
Summary: DNA testing of 1,600 tortoises on Isabela Island in the Galapagos has suggested a giant tortoise species long thought to have gone extinct in the mid-1800s may still be alive. Among the native Chelonoidis becki tortoises, researchers found at least 84 animals that were the direct offspring of a different tortoise species, Chelonoidis elephantopus, which originally lived on nearby Floreana Island, an island that now has no tortoises.
The 84 tortoises were Isabela/Floreana hybrids, but the scientists think there could potentially be 38 or more pure blooded Floreana tortoises still alive on Isabela Island. "The only way these hybrids could be produced is if we had some pure Floreana animals still alive on the island… because some of these animals are hybrids which are first-generation crosses," Adalgisa Caccone, an evolutionary biologist at Yale University, says.
The researchers believe the Floreana animals were taken by whalers onboard ships to be used as food but then must have been dropped off or escaped in order to find their way to Isabela island, which was never settled by humans.
This discovery dates to 1994 when the same researchers took 60 blood samples from tortoises living on the sides of a volcano on Isabela. Caccone says they found some individuals so divergent genetically they were referred to as “aliens.” Years later, after DNA analysis had improved, tests of bone and shell from extinct Galapagos tortoise species kept in museums revealed that the “aliens” had actually come from Floreana island. An expedition involving 50 people spent two weeks recently on Isabela and took 1,660 blood samples to confirm these conclusions.
While the scientists did not find any purebred Chelonoidis elephantopus individuals, they are satisfied that the purebreds are there on Isabela island and reproducing. If pure blooded animals are found, they will be reintroduced to their home island of Floreana. Otherwise, a breeding program might back cross the hybrids to build up a population closer to full-blooded Floreanas, which would later be taken to Floreana.
The Galapagos tortoises are among the animal species there that Charles Darwin said helped him form his ideas on evolution. Darwin noted that many of the islands had their own, distinct, tortoise species and inferred that each species had evolved to survive best on its own home island. Some of the Floreana tortoises, which can live to be 100 or older, may be the children of ones that Darwin saw.
(Thanks to Dr. Bruce Holman for suggesting this story.)
(Photo of a Galapagos tortoise with a scientific name [Geochelone elephantopus] similar to the “extinct” species is from Wikimedia Commons, credited to Matthew Field.)
To read the entire article, click on USA TODAY.
Comment: Where did Darwin go wrong in the Galapagos, considering he obviously was correct in his observation that different environments can lead to differences in animals? Like evolutionary scientists today, he erred when he inferred that minor changes in animals (variations within a type of animal) can be strung together in such a way that they can lead to major changes (molecule-to-man evolution).
However, nature cannot be shown to be a ladder, where one step will take you to another and another and another. The overwhelming evidence indicates that while there is room for variation within the genome of each type of animal, there are also strict limits to how much change is possible. Limited variation, sometimes called microevolution, is affirmed by all scientists, evolutionist and creationist alike. However, creationist scientists want to see evidence for the microbe-to-man type of change, referred to as macroevolution or Darwinian evolution.
It is easy for the people to be fooled. A type of faulty reasoning, called affirmation of the consequent, is sometimes employed to convince people that major changes, aka macroevolution, can occur and have occurred. This false logic takes a form something like the following: If A is true, we should see B. We see B. Therefore A is must be true. Sounds reasonable, doesn’t it? But many examples can be provided to show this approach can produce entirely wrong conclusions. For instance, consider: If there is a total eclipse of the sun, it should be dark outside. It is dark outside. Therefore, there must be a total eclipse of the sun. This thinking can be faculty because B can be due to other reasons besides A.
An evolutionist then might reason: If evolution is true, we should see changes in animals. We do see changes in animals. Therefore evolution must be true. But the changes we see in animals such as the tortoises are due to their genomes which permit some variation, but they are not due to Darwinian evolution. For example, the animals that descended from the “cat kind” which left Noah’s ark have taken on various different appearances and sizes, but they are all clearly cats. No part-cat, part-non-cat has ever been documented. The changes in felines down through the ages have been limited.
The human race today also displays many differences in appearance, but we are all clearly human. We are all descended from the original pair of humans, Adam and Eve, and also from the four couples aboard the ark. While different in some respects, we are all perfectly alike in one crucial way. We are all sinful creatures in desperate need of a Savior. And we all indeed do have a Savior. We are being offered total forgiveness of our sins and the assurance that through faith in Jesus Christ, heaven will be our future home. “Believe in the Lord Jesus, and you will be saved” (Acts 16:31).
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QUESTION OF THE DAY
Where is the world’s longest bridge over water?
The Qingdao Haiwan Bridge (aka Jiaozhou Bay Bridge) in northwest China covers 26.4 miles, making it the world’s longest sea bridge. The bridge opened in June, cost an estimated $2.3 billion, and required enough steel to build seven Empire State Buildings. (Photo from Wikipedia)
Source: Discover (November, 2011)
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