Bumblebees sense flowers’ electric fields

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Bumblebees (Bombus terrestris) can detect flowers’ electric fields, scientists have discovered. Results indicate floral electric fields improve the bees’ ability to discriminate between different flowers. When used with visual signals, electrical cues can enhance the bee’s memory of floral rewards. Researchers suggest this method of signalling provides rapid and dynamic communication between plants and pollinators.

The findings are published in the online journal Science Express.

Flowering plants reward pollinators with nectar and pollen in return for their assistance in the flowers’ sexual reproduction. Flowers attract pollinators using cues such as bright colours, patterns and enticing fragrances but this study suggests the importance of electrostatic information as an additional cue for the first time.

“Of course it has existed for a long time but this is a new way we can look at the interactions between bees and flowers,” said Prof Daniel Robert of the University of Bristol. “This doesn’t throw away any of the previous work on cues that flowers are using, it adds another layer on top of that.” Prof Robert and his team were studying the mechanism of pollen transfer between flowers via an insect pollinator.

“What the pollen needs to ‘know’ is when to ‘jump’ onto the ‘vehicle’ – the bee – and when to get off it. So it’s a selective adhesion type of question,” Prof Robert told BBC Nature.

The team’s investigation highlighted the possible importance of electrostatic forces. “We looked at [existing] literature and realised that the bees were being positively charged when they fly around, and that flowers have a negative potential. “There’s always this electrical bias around. As a sensory biologist, suddenly I thought: can the bees sense that?” Prof Robert said.

Dominic Clarke, one of the lead authors, designed “fake” electric flowers in a laboratory “flying arena” to prove that electric fields are important floral cues. Electric flowers with a positive charge offered a sucrose reward while those without offered a bitter quinine solution. Bumblebees were allowed 50 visits in the flying arena and the last 10 visits showed the bees had learnt to tell the difference between the flowers.

When the electric field was turned off, “the bee goes back to selecting at random because it hasn’t got a way to tell the difference between them any more,” commented Mr Clarke. “That’s how we know it was the electric field that they were learning.”

“Animals are just constantly surprising us as to how good their senses are. More and more we’re starting to see that nature’s senses are almost as good as they could possibly be,” Mr Clarke told BBC Nature. Prof Robert summed up: “We know they can detect these electrostatic fields… this is the tip of the iceberg, there’s so much more that we haven’t seen yet.”

http://www.bbc.co.uk/nature/21508035

Thanks to Kebmodee for bringing this to the attention of the It’s Interesting community.

Meteorite has highest water concentration of any yet discovered from Mars

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A team of scientists has established a whole new class of meteorites that seems to have come from Mars’ crust, based on a rare sample from 2.1 billion years ago.

The newly analyzed meteorite has more water than any other Martian meteorite that we know of, by a magnitude of more than 10, said Carl Agee, lead study author and director of the Institute of Meteoritics at the University of New Mexico. Agee and colleagues published their analysis of the meteorite in the journal Science Express.

“There are thousands and thousands of meteorites, and so far this is the only one like it,” Agee said.

This is a volcanic rock that was probably part of an eruption, and interacted with water to the extent that some water got incorporated into the structure of the minerals, Agee said. “That’s why we’re able to see it after a couple of billion years,” he said.

The precise source of the water in the meteorite is unknown. It could have come from a lake or stream, or ground water that a volcano intruded into, Agee said. Alternatively, the water could have come from frozen Martian tundra that melted when hot volcanic material moved through it.

“We do know that there was a significant amount [of water] available,” he said.

Agee and colleagues were able to extract water from the meteorite by putting it into a vacuum-sealed tube and heating it up. Using a mass spectrometer, they were able to determine that the gas released from the heated meteorite was water vapor.

“That vapor is true Martian water that is, sort of like, being awakened” after many years, he said. “We’re pulling it out of the rock.”

Agee’s meteorite is similar to the type of rocks that NASA spacecraft have found on the surface of Mars in terms of its chemical composition. This is the first meteorite that’s a good match to those rocks on Mars today.

The meteorite’s age also makes it unique, Agee said. It from 2.1 billion years ago, making it the second-oldest sample that we have. The oldest is the Alan Hills meteorite, discovered in Antarctica in 1984, which is 4.5 billion years old. All other samples have been much younger.

Right now, Mars is cold and dry, inhospitable for life, Agee said. But many scientists believe the environment used to be warm and wet and that somewhere in its history the planet lost its atmosphere and surface water. When and how that happened are big mysteries.

“This meteorite is a sample from that transitional period, perhaps,” Agee said. “Because of the water that’s present in it, it may be giving us a glimpse of what the surface conditions were like, as well.”

The rare Mars rocks came from Morocco. There are nomads in that country who make a living by scouring the Sahara Desert for the dark, black rocks that have fallen from space, Agee explains. They bring these meteorites into towns and sell them to a dealer. Then the dealer sells them internationally to collectors, museums and scientists.

When Agee realized how rare and important his first sample was, he wanted to know if there were more. The meteorite hunters have since recovered a few more pieces.

The biggest piece of this Martian meteorite fits into the palm of your hand and weighs 320 grams (about 11 ounces), Agee said. There are two samples in his lab and two more in Paris.

“It’s going to be real interesting to see if there are more that are recovered,” he said. “But I think that this particular type is going to be extraordinarily rare.”

Meteorite has highest water content of any from Mars, scientists say