Cold is hot in evolution -- Researchers debunk belief species evolve faster in tropics

Mar 15, 2007

University of British Columbia researchers have discovered that contrary to common belief, species do not evolve faster in warmer climates.

UBC Zoology PhD candidate Jason Weir and his mentor Prof. Dolph Schluter, director of the UBC Biodiversity Research Centre, charted the genetic family tree of 618 mammal and bird species in the Americas over the last several million years.

By analyzing the DNAs of species that are closely related to one another, the researchers found that speciation – the process in which one species splits into two – takes place faster in temperate zones than in the tropics. Their findings are published in today’s edition of the journal Science.

"It’s been long established that the tropics have more species, but it’s not clear why," says Weir. "The common assumption is that species simply evolve faster in warmer climates."

"Our analysis shows that new species actually evolve faster as we move towards the poles. It would take one species in the tropics three to four million years to evolve into two distinct species, whereas at 60 degrees latitude, it could take as little as one million years."

The higher speciation rate in higher latitudes, however, is counteracted by a high extinction rate, both likely due to more intense climate fluctuations, says Weir.

"In comparison, even though there is a lower speciation rate in the tropics, the stable environment contributes to an equally low extinction rate. As a result, more species survive. This could help explain why there are more species in general in warmer climates," says Weir.

"In other words, there’s a higher turnover of species in places like Canada, making it a hotbed of speciation, not the Amazon," says Schluter.

Source: University of British Columbia

Explore further: Researchers combat bias in next-generation DNA sequencing

Related Stories

New research reveals first warm-blooded fish

May 14, 2015

New research by NOAA Fisheries has revealed the opah, or moonfish, as the first fully warm-blooded fish that circulates heated blood throughout its body much like mammals and birds, giving it a competitive ...

Evolution puts checks on virgin births

Apr 17, 2015

It seems unnatural that a species could survive without having sex. Yet over the ages, evolution has endowed females of certain species of amphibians, reptiles and fish with the ability to clone themselves, ...

The vital question: Why is life the way it is?

Apr 01, 2015

The Vital Question: Why is life the way it is? is a new book by Nick Lane that is due out on April 23rd. His question is not one for a static answer but rather one for a series of ever sharper explanations—explanations that a ...

Recommended for you

Researchers combat bias in next-generation DNA sequencing

45 minutes ago

Ever since scientists completed mapping the entire human genome in 2003, the field of DNA sequencing has seen an influx of new methods and technologies designed to help scientists in their search for genetic ...

11 new species come to light in Madagascar

5 hours ago

Madagascar is home to extraordinary biodiversity, but in the past few decades, the island's forests and associated biodiversity have been under greater attack than ever. Rapid deforestation is affecting the ...

Birds 'weigh' peanuts and choose heavier ones

May 23, 2015

Many animals feed on seeds, acorns or nuts. The common feature of these are that they have shells and there is no direct way to know what's inside. How do the animals know how much and what quality of food ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.