Tropical bird species evolved without isolation: study
Last Updated: Wednesday, November 14, 2007 | 4:20 PM ET
CBC News
Evolutionary theorist Charles Darwin had it right when he said different species could develop in the same place, a new Canadian-led study suggests.
Darwin's theory of sympatric speciation — distinct species evolving from a single parent species within a geographic area — first appeared in his 1859 book The Origin of Species. He was not able to prove it, and the dominant theory since has been allopatric speciation — that a barrier, such as a mountain, glacier or ocean, is required to produce separate species.
Now, 148 years later, research led by Queen's University in Kingston, Ont., may prove the existence of sympatric speciation. The international research team found that this type of evolution could occur by "allochronic isolation," or separation by breeding times.
Prior to the study, released this week in the journal Proceedings of the National Academies of Science, there were only two documented cases of species evolving in the same place and no clear evidence as to how it would occur in nature.
The research team studied a species of tropical seabird known as the Madeiran or the band-rumped storm petrel, which populate archipelagos in the tropic and sub-tropic, and have different breeding seasons. Some colonies have a single breeding season, others prolonged seasons, and in five locations, there are two distinct breeding seasons. The research focused on the latter five areas.
Researcher Andrea Smith told CBC News the team was interested in whether the difference in breeding periods "was a barrier to drive them to become separate species."
By analyzing genetic variation in the species, they found the petrel populations differed genetically in all five locations and had ceased to exchange genes in two.
"The seasonal populations from four of the locations are more closely related to each other than populations from the same breeding seasons elsewhere," said Smith, suggesting that "one arose from the other just out of the separation of breeding."
The study says this finding suggests that "seasonal populations appear to have arisen sympatrically at least four times." Additionally, they found that the species had not interbred for between 1,000 to 180,000 years.
"I think it's exciting for a number of reasons," said Smith. "One is that it's challenging the idea that you need a geographic barrier for species to arrive."
She said the findings also suggest that this mode of speciation might be more common than researchers had previously thought.
Smith said their discovery could lead to changes in species protection.
"In finding that there are actually populations that are considered separate species, it indicates that we need to be looking into conservation for these species, because a lot of them are represented only by a couple hundred birds," she explained. "We don't want to lose that biodiversity that we've documented."
Corrections and Clarifications
- In five locations, the tropical seabird known as the Madeiran has two distinct breeding seasons. An earlier version of the story incorrectly reported there were periods when there was no breeding at all. Nov. 14, 2007|11 p.m. ET
Share Tools
Top News Headlines
- Greece passes new austerity deal amid rioting
- Greek lawmakers have approved harsh new austerity measures demanded by bailout creditors to save the debt-crippled nation from bankruptcy, after riots in Athens and other cities left stores looted and burned and more than 120 people hurt. more »
- Quebec town 'heartbroken' after killing of woman, sisters
- A small Quebec town is in mourning Sunday after a Quebec man was charged with killing his nieces and his mother, who were found dead in their family home. more »
- Houston autopsy results withheld by police
- Whitney Houston was found in a hotel bathtub but it'll take weeks to determine precisely how she died, a Los Angeles coroner's official says. more »
- Musicians who died before their time
- The growing list of musicians who have died young. more »
Latest Technology & Science News Headlines
- Ancient Antarctic lake may harbour microbial life
- If scientists find microbes in a frigid lake 3.2 kilometres beneath the thick ice of Antarctica, it will illustrate once again that somehow life finds a way to survive in the strangest and harshest places, and it will offer hope that life exists beyond Earth. more »
- B.C. killer whale habitat protection ruled a legal duty
- The federal minister of fisheries has no discretion when it comes to protecting the critical habitat of B.C.'s southern resident killer whales, the Federal Court of Appeal has ruled. more »
- Game developer seeks $400K, makes $1M in a day
- Videogame studio Double Fine went on the website Kickstarter to raise $400K US in a month to develop a new game. They reached that target in a matter of hours. more »
- McGill asbestos study review criticized
- A group of anti-asbestos activists and scientists are criticizing McGill University's plans for an internal review of a major asbestos research study that has been called into question. more »
Bob McDonald's Blog
Glacier Discovery Walk: Will the visitor centre enhance the view? Feb. 10, 2012 3:17 PM Environment minister Peter Kent has announced the construction of a new Glacier Discovery Walk and visitor centre on the Icefields Parkway in Jasper National Park. It raises the issue of how to balance commercial development in our National Parks against the preservation of the last refuges of wilderness.
Quirks & Quarks
- February 11: Inside the Mind of a Neandertal Feb. 10, 2012 4:01 PM Can we get inside the mind of a species that's been dead for 30,000 years? A new book, How to Think Like a Neanderthal, suggests we can. The authors reconstruct a creature like us in many ways, but with important differences.
Latest Features
- Adele wins best album, best record Grammys
- Houston autopsy results withheld by police
- Quebec town 'heartbroken' after killing of woman, sisters
- Northern lights viewed from space
- Greece passes new austerity deal amid rioting
- Pop queen Whitney Houston dies at 48
- Manitoba man dies after falling off moving SUV
- Doors blocked in fatal Manitoba trailer blaze
- Former Stanley Park petting zoo goats feared slaughtered

