evolution by natural selection

"Survival of the fittest" is the catch phrase of evolution by natural selection. While natural selection favors the most fit organisms around, evolutionary biologists have long wondered whether this leads to the best possible organisms in the long run.

A team of researchers has developed a new theory, which suggests that life may not always be optimal.

When Charles Darwin first set foot on Patagonia, he was a fresh-faced 22-year old yet to finesse his revolutionary theory of evolution by natural selection.

But traveling around the tip of South America aboard the HMS Beagle--part of an epic, five-year scientific expedition--the young naturalist had his eyes opened to the immense diversity of species and landscapes.