91热爆

Genetically modified Bt crops have been hailed as one of the success stories of GM crops. Cotton, maize and soybeans which have the 鈥榠nsecticide gene inserted鈥� are thought to be responsible for increases in global agricultural productivity of US$78 between 1996 and 2013. But now farmers are starting to see crop pests developing resistance to the Bacillus thuringiensis toxin. It鈥檚 one of the evolutionary arms races that nature is so famous for. But now scientists at Harvard University are harnessing evolution in the lab to fast-track themselves to a new generation of the insecticidal toxin.

Cricket Calls
Cricket songs get higher as the temperature rises 鈥� Crickets 鈥榮ing鈥� to attract mates and ward off rivals. The problem is lots of other insects make noises for the same reason. So how does the cricket make sure other crickets can hear him? He broadcasts on a particular frequency. But, as tree crickets make sound by rubbing their wing cases together, when the temperature rises during the day, their muscles twitch faster and the sound gets higher. New research shows that they can tune the sound back to the correct frequency.

Ice Sails
On Science in Action, we like phenomena, especially 鈥榚phemeral phenomena鈥� 鈥� strange things that pop up, then disappear. Like ice sails - oddly beautiful structures you may come across if you鈥檙e lucky enough to be walking along one of the glaciers streaming in slow motion off the Karakoram mountain range spanning the borders between Pakistan, India, China and Afghanistan. Ice sails are huge sail-shaped chunks of ice, only found in this region and only found between certain altitudes. Now scientists have worked out how they are made and why they are so unusual. It鈥檚 important as it tells us about how the glaciers works and these glaciers provide a lot of drinking water for a lot of people.

Wildlife in the Chernobyl Exclusion Zone
In the 30 years since the Chernobyl nuclear accident, what has happened to the wildlife in the 30Km exclusions zone?

LA鈥檚 Wildlife
Pink glow worms and 3 new species of snail have been discovered in the unlikely 鈥榗oncrete jungle鈥� that is Los Angeles. All thanks to an army of citizen scientists searching for and reporting the wildlife in Southern California. The work is part of the new Urban Nature Research Center launched by the Natural History Museum of Los Angeles County and they say it鈥檚 鈥渢he largest urban biodiversity study in the world.鈥�

(Photo: A cotton field waits to be harvested on BTC farm which raises 1000 acres of cotton, 80% of which is genetically modified (GM) Bt, Roundup Ready cotton. 漏 Scott Olson/Getty Images)

Presenter: Jack Stewart
Producer: Fiona Roberts