The Galapagos Islands are the famous breeding grounds for the giant Galapagos Tortoise that were first discovered by a Spanish priest, Tomas de Berlanga in 1535 when he was sailing from Panama to Peru. A storm blew the priest’s ship off-course and he landed in the Galapagos Islands. Since that time, the Galapagos Tortoise has suffered immeasurable damage due to man’s exploitation. Sailors, whalers and pirates exploited the tortoises for food because they discovered the Galapagos Tortoise could survive up to a full year without food or water. This made the tortoises a perfect food for long sea voyages, where perishable foods would spoil. Apparently, they would simply be turned upside down and stored on board ships until they were consumed. It is estimated that approximately 100,000 tortoises were killed this way.
Ironically, this astounding evolutionary advantage, almost led to their complete extinction because of man’s exploitation. Without this exploitation, the tortoises were thriving on a lush tropical island chain, free of predators, with little competition for food due to the lack of indigenous species. In addition to these favourable characteristics, the Galapagos Tortoise has an extremely low metabolism which is the reason they could survive on board ships for a full year with no food or water.
As the average life-span for a Galapagos Tortoise is over 100 years, (with some surviving up to 150 years), it is tempting to associate low metabolism as a favourable characteristic for long life. However, there are a number of other characteristics to consider:
Galapagos Tortoise Exhibits Negligible SenescenceSenescence refers to the development of aging symptoms. Humans are considered to exhibit these symptoms because as we age our cells deteriorate resulting in numerous depleted abilities from our youth. The Galapagos Tortoise however, does not appear to exhibit depletion of the following important abilities with age, therefore it is considered to be one of the species exhibiting “negligible senescence”:
-decreased capability of reproduction
-decreased strength, mobility, hearing and eyesight
-age related increases in disease
-age related increase in death rate,
Most animals in the world exhibit reduced abilities with age, so it is truly remarkable to find species that do not exhibit deterioration of important life sustaining functions. Understanding of these abilities and determining where they originate is key to unlocking the secret to old age with NO deterioration of function in humans. Is this ability genetic? Has the ability evolved through natural selection? Why is it present in only certain species? These are just some of the questions being addressed through current research.
Other Animals with Negligible SenescenceThere are other animals that also exhibit negligible senescence and they include Rougheye rockfish (205 years), lake sturgeon (152 years), certain clams (~160 years) and lobsters (140 years).
On-going Research in Negligible SenescenceAlthough negligible senescence was discovered in the 1930’s, the study of animals that exhibit this favourable trait is still only in its infancy. The problems in studying some animals with these traits is that normally to get significant age data, it is necessary to kill the animal, therefore the maximum age cannot be determined. Among the more recent and promising research is on rockfish, where it was discovered that 16% of the all the rockfish being caught by fishermen for human consumption were over 50 years old (ageless animals.org) and some were over 100 years old.
With continued research, there will certainly be advances in this promising, yet virtually untouched field of study. This is just one reason why the preservation of the Galapagos Tortoise along with other species exhibiting negligible senescence is so important.
Galapagos Tortoise May Hold Key To Long Life
Thankfully, the country of Ecuador has taken an active role to preserve these magnificent creatures. There is a breeding center on one of the islands where eggs are taken from the wild, hatched in incubators and then young tortoises are raised to sizes in which they are no longer susceptible to predators and are then released to the wild. With this help, the Galapagos Tortoise populations are stabilized if not increasing. Who knows, we may even learn to do this with other species in the future.
Maddalena Environmental inc.