A new study published in Biology Letters calls into question elements of Charles Darwin's theory of evolution.
While Darwin argued that competition was the key force driving evolution, a research team from the University of Bristol argues that "living space" is in fact the primary driver. Michael Benton, a co-author of the study, said his team concluded that "competition did not play a big role in the overall pattern of evolution."
"The new study proposes that really big evolutionary changes happen when animals move into empty areas of living space, not occupied by other animals," BBC News explains. "For example, when birds evolved the ability to fly, that opened up a vast range of new possibilities not available to other animals. Suddenly the skies were quite literally the limit, triggering a new evolutionary burst."
Slate describes how PhD student Sarda Sahney conducted her research:
Using fossils to study evolutionary patterns over hundreds of millions of years of history, Sahney and team found that biodiversity, at least among the land animals that they decided to focus on, matched the availability of living space through time. Living space refers to the particular requirements of individual organisms to thrive and reproduce. It can include several components but primarily describes the availability of food and favorable habitat.
"Throughout geological time, patterns of global diversity of tetrapod families show 97 per cent correlation with ecological modes," Sahney writes in the Biology Letters article co-authored by Michael Benton and Paul Ferry.
Not all have accepted the team's conclusions. According to BBC News, Yale University evolutionary biologist Stephen Stearns said the interpretation was "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?" Stearns asked.