Zee Media Bureau/Salome Phelamei
Washington: Charles Darwin`s Galapagos theory that states animals living on islands were tamer than on the mainlands has been proven correct by the scientists in a new study.
Researchers from the University of California, Riverside, Indiana University, Purdue University, Fort Wayne and George Washington University have found that that lizards living on islands are indeed tamer than those living in the mainland.
Our study confirms Charles Darwin`s observations and numerous anecdotal reports of island tameness. His insights have once again proven to be correct, and remain an important source of inspiration for present-day biologists," said Theodore Garland, professor of biology at University of California, Riverside.
More than 150 years ago, Darwin, the founder of the theory of evolution, surveyed the Galapagos Island to observe the animals living there. As Darwin noticed the relatively calm, unthreatened nature of the animals populating the Islands, he questioned whether they had evolved this way due to their lack of predators.
Darwin observations later became his inspiration for his most famous theory, natural selection, which states that animals would develop new functions to help them better the survival chances as the environment change.
In the study, researchers examined the connections of flight initiation distance (the predator-prey distance when the prey starts to run), distance from the mainland, island area and activities of 66 different species of lizards.
The study, which was published in the online journal Proceedings of the Royal Society B, focused on lizards collected from five continents and islands in the Atlantic and Pacific Oceans, and the Caribbean and Mediterranean Seas.
The scientists found that island tameness exists and that there is a decrease of flight initiation distance the farther the lizard is from the mainland.
The team also discovered that the size of the prey can play an important factor in determining flight initiation distance, because predators do not attack small, isolated prey.
“When prey are very small relative to predators, predators do not attack isolated individual prey,” Garland explained. “This results in the absence of fleeing or very short flight initiation distance.”
