A new study could shake the very foundations of Darwin’s theory of evolution, which says that ‘living space’ and not competition, was the major driving force of evolution.
The study at University of Bristol claims that Charles Darwin may have been wrong when he imagined a world in which organisms battled for supremacy and only the fittest survived.
PhD student Sarda Sahney and colleagues used fossils to study evolutionary patterns over 400 million years of history.
The team said that the amount of biodiversity closely matched the availability of "living space" through time.
Living space - more formally known as the "ecological niche concept" by biologists - refers to the particular requirements of an organism to thrive. It includes factors like the availability of food and a favourable habitat.
For instance, birds that took to flight for the first time opened up a vast range of new possibilities not available to other animals.
"For example, even though mammals lived beside dinosaurs for 60 million years, they were not able to out-compete the dominant reptiles. But when the dinosaurs went extinct, mammals quickly filled the empty niches they left and today mammals dominate the land," BBC News quoted Professor Mike Benton as saying.
However, Professor Stephen Stearns, an evolutionary biologist at Yale University did not agree, saying that he "found the patterns interesting, but the interpretation problematic".
“What is the impetus to occupy new portions of ecological space if not to avoid competition with the species in the space already occupied?" he asked.
The study is published in Biology Letters.