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

March 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: Passenger pigeon genome shows effects of natural selection in a huge population

Related Stories

Scientists demonstrate one of largest quantum simulators

November 29, 2017

Physicists at MIT and Harvard University have demonstrated a new way to manipulate quantum bits of matter. In a paper published today in the journal Nature, they report using a system of finely tuned lasers to first trap ...

Tree rings used to counter smugglers' rings

November 14, 2017

Analysing regional differences in the DNA of wood and has allowed scientists to determine the location of the original tree within 15km, and the work could help crack down on the billion-euro trade in illegal timber.

In the fight against viral infection, spelling counts

November 13, 2017

For millions of years, humans and viruses have engaged in a constant tug of war: as our cells evolve new ways to defend us from our viral enemies, these pathogens in turn acquire new traits to sidestep those defenses.

Recommended for you

Faster, more accurate cancer detection using nanoparticles

December 12, 2017

Using light-emitting nanoparticles, Rutgers University-New Brunswick scientists have invented a highly effective method to detect tiny tumors and track their spread, potentially leading to earlier cancer detection and more ...

0 comments

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.