2-hour wildfire evacuation notice issued for some Fort McMurray neighbourhoods
A wildfire evacuation alert for some Fort McMurray residents has been updated to a two-hour evacuation notice.
Scientists have a new idea for how Earth got its oxygen: It's because the planet slowed down and days got longer.
A study published Monday proposes and puts to the test the theory that longer, continuous daylight kick-started weird bacteria into producing lots of oxygen, making most of life as we know it possible.
They dredged up gooey purple bacteria from a deep sinkhole in Lake Huron and tinkered with how much light it got in lab experiments. The more continuous light the smelly microbes got, the more oxygen they produced.
One of the great mysteries in science is just how Earth went from a planet with minimal oxygen to the breathable air we have now. Scientists long figured microbes called cyanobacteria, were involved, but couldn't tell what started the great oxygenation event.
Researchers in a study in Monday's Nature Geoscience theorize that Earth's slowing rotation, which gradually lengthened days from six hours to the current 24 hours, was key for the cyanobacteria in making the planet more breathable.
About 2.4 billion years ago there was so little oxygen in Earth's atmosphere that it could barely be measured, so no animal or plant life like we know could live. Instead, lots of microbes breathed in carbon dioxide, and in the case of cyanobacteria, produced oxygen in the earliest form of photosynthesis.
At first it wasn't much, but in only about 400 million years Earth's atmosphere went to one-tenth the amount of oxygen we have now - a huge jump, said the study's lead author, Judith Klatt, a biogeochemist at the Max Planck Institute in Germany. That oxygen burst allowed plants and animals to evolve, with other plants now joining in the oxygen-making party, she said.
But why did the bacteria go on the oxygen making binge? That's where University of Michigan oceanographer Brian Arbic comes in. He studies tidal forces on Earth and how they've slowed Earth's rotation. Arbic was listening to a colleague's lecture about cyanobacteria and he noticed that the oxygen event coincided with the timing of Earth's days getting longer. The planet's rotation slows because of the complicated physics of tidal friction and interaction with the moon.
The Michigan and German researchers put their theory to the test with bacteria similar to what would have been around 2.4 billion years ago. They used purple and white mats of cyanobacteria living in an eerie world of the sinkhole nearly 79 feet (24 meters) deep in Lake Huron.
“We actually imagine that the world looked kind of like the Middle Island sinkhole for most of its history,” Klatt said.
Divers brought up the gelatinous carpets of bacteria, which smell like rotten eggs. Klatt and colleagues exposed them to varying amounts of light, up to 26 straight hours. They found that more continuous light caused the microbes to produce more oxygen.
The study authors and outside scientists said this is just one possible but plausible explanation for Earth's oxygen increase.
What makes the idea so impressive is that it doesn't require any big biological changes in bacteria or the world's oceans, said Tim Lyons, a professor of biogeochemistry at the University of California, Riverside, who wasn't part of the research team.
The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute's Department of Science Education. The AP is solely responsible for all content.
A wildfire evacuation alert for some Fort McMurray residents has been updated to a two-hour evacuation notice.
Saskatchewan RCMP are set to provide an update on what the service calls a 'significant' sexual assault and internet child exploitation investigation.
Canadian LifeLabs customers who filed an application for a class-action settlement began receiving their payments this week, though at a much lower amount than initially expected.
Nobel laureate Alice Munro, the Canadian literary giant who became one of the world's most esteemed contemporary authors and one of history's most honoured short story writers, has died at age 92.
Wildfires have led Environment Canada to issue air quality advisories for parts of B.C., Alberta, Manitoba, Saskatchewan and the Northwest Territories, as forecasters warn the smoke could drift farther east.
An American accused of sexually assaulting a Pennsylvania college student in 2013 and later sending her a Facebook message that said, 'So I raped you,' has been detained in France after a three-year search.
The annual list of Canada's top restaurants in the country was just released and here are the places that made the 2024 cut.
Ontario Provincial Police are responding to a fatal collision involving two vehicles on Highway 417 in Ottawa's west end on Tuesday morning.
The Israeli flag is flying at Ottawa City Hall today to mark the country's national day, with plans to hold a private ceremony to mark Israel's Independence Day. There is a significant police presence at City Hall, including security barriers outside the main doors.
A team is ready to help an entangled North Atlantic right whale in the Gulf of St. Lawrence.
A $200 reward is being offered by a North Vancouver family for the safe return of their beloved chicken, Snowflake.
Two daughters and a mother were reunited online 40 years later thanks to a DNA kit and a Zoom connection despite living on three separate continents and speaking different languages.
Mother's Day can be a difficult occasion for those who have lost or are estranged from their mom.
YES Theatre Young Company opened its acclaimed kids’ show, One Small Step, at Sudbury Theatre Centre on Saturday.
An Ottawa pizzeria is being recognized as one of the top 20 deep-dish pizzas in the world.
A family of fifth generation farmers from Ituna, Sask. are trying to find answers after discovering several strange objects lying on their land.
A Listowel, Ont. man, drafted by the Hamilton Tigercats last week, is also getting looks from the NFL, despite only playing 27 games of football in his life.
The threat of zebra mussels has prompted the federal government to temporarily ban watercraft from a Manitoba lake popular with tourists.