It made sense to Charles Darwin that animals ihhabiting tropical islands would be tamer and more people friendly than their land locked counter parts, for islands such as the Galapagos that Darwin once so famously visited support fewer large animals, and thus fewer natural predators for smaller animals to consider. As per his Theory of Evolution, animals in such an environment would gradually adapt to less hostile conditions; thus, less cautious individuals would no longer be weeded from the population.

Darwin, of course, was a busy man and lacked the more scientific means used today. His theory hadn't been tested until a recent study by researchers from UC Riverside, Indiana University, Purdue University, and George Washington University (Fort Wayne, IN), Laboratory Equipment reported.

Their study not only validated Darwin's observation, but provided a more specific explanation. Animals less likely to flee are naturally selected for on islands, at least in the case of lizards. They expend less energy running away from perceived threats and more of their efforts searching for food and reproducing, according to the study.

Researchers measured how tame island lizards were compared to similar species on land in five continents simply by calculating how close they could get before the lizards would flee. They discovered a negative relationship between the distance from the mainland and the distance humans could achieve before the lizards would escape, meaning as the distance to the mainland increased, the distance between scientist and researcher decreased.

"Our study confirms Darwin's observations and numerous anecdotal reports of island tameness," said Theodore Garland, a professor of biology at UC Riverside. "His insights have once again proven to be correct, and remain an important source of inspiration for present-day biologists."

Interesting, researchers found that prey size is also indirectly related to flight initiation, meaning researchers were able to get closer to smaller animals. Presumably, larger predators wouldn't risk wasting an approach for such a small meal.

"When prey are very small relative to predators, predators do not attack isolated individual prey," Garland said. "This results in the absence of fleeing or very short flight initiation distance."

Garland conceded that other factors might have also spurred "island tameness."

"It is possible that other factors favor island tameness. For example, if food is scarce on islands, the cost of leaving food to flee would favor shortened flight initiation distance," he said