It’s a question that has captivated naturalists for centuries: Why have some groups of organisms enjoyed incredibly diversity—like fish, birds, insects—while others have contained only a few species—like humans.
It’s a question that has captivated naturalists for centuries: Why have some groups of organisms enjoyed incredibly diversity—like fish, birds, insects—while others have contained only a few species—like humans.
Researchers trying to explain why the Tree of Life is so unbalanced have agreed on a few explanations—a species’ ability to change colour, its body size, and how it interacts with its environment all influence how quickly it can form new species compared to other organisms. Geological age has also been a major explanation—older groups of organisms have had more time to accumulate more species.
But new research in the Proceedings of the National Academy of Sciences shows the passage of time has a surprising, and consistent impact on evolutionary diversity—and might favour young species.
“If you look at rates of macroevolutionary diversification across 3.8 billion years, it’s younger groups of organisms, on average, that accumulate diversity much more quickly than older groups,” says Matthew Pennell, an evolutionary biologist at the University of British Columbia and senior author on the paper.
Read more at University of British Columbia
