Home is where the temperature is right as far as plants are concerned, even when great expanses of Arctic Ocean are in the way. An Arctic Island plant study shows that the limiting factor for species migration during climate change is the local climate, not how far the seeds have to go to get there.

The Arctic could be ice-free in summer as soon as 2020. A study of Arctic ice measurements from 1953 to 2006 predicts ice-free summers 30 years earlier than the previously predicted 2050-to-early-22nd-century window. This is not only bad news for polar bears, it accelerates global warming: dark ocean waters absorb more solar heat than reflective ice cover.

Humans can be motivated to work harder without even knowing it. The trick is to subliminally suggest that greater rewards await greater efforts. A brain imaging study showed that subjects worked harder when images of higher amounts of money were flashed to them subliminally than images of lower amounts.

The interactions among plants and insects in a field turns out to be a good measure of the impact of global warming, and the outlook is not promising. Things looked good early on in a field study of grasslands that simulated coming climate change. For two years production and diversity increased. But after five years the grass took over and plant diversity fell by half. Flowering plants in particular were suppressed, leaving insects with far less food.

Collaborative tagging sites like del.icio.us are examples of systems that harvest crowd intelligence. The collective behavior of thousands of people acting independently produces a solution.

It turns out that even though people are acting intelligently and independently, collaborative tagging behavior follows two simple rules: the rich get richer, i.e. more popular tags get more popular, and recent tags are picked more frequently than older tags.

Hmm. If something can be modeled it can often be reverse-engineered. So what happens when someone comes up with an algorithm that does “collaborative” tagging automatically?

It turns out that subliminal distractions throw off your game more than the consciously annoying kind. A study found that subliminal visual distractions impaired task performance more than visual distractions that subjects consciously perceived. It looks like subliminal visual distractions get past the parts of the brain that filter out visual noise.

Some animals hunt cooperatively, but usually the teamwork involves the same species. Scientists have found an example of cross-species cooperative hunting in the Red Sea — groupers and giant moray eels.

Groupers hunt in open water and moray eels hunt in coral reefs. Prey fish fleeing groupers often take shelter in coral reefs and prey fish fleeing moray eels often take to open water. This sets the stage for a strategic partnership.

The scientists saw groupers signaling moray eels by approaching the eels and shaking their heads from side to side. The eels then followed the groupers and they hunted together. Sometimes during the hunt, groupers stood on their heads to signal that prey was hiding in particular crevices.

The theory is the partnership works because groupers and moray eels swallow their prey in a single bite so there is no fighting over carcasses to sour the relationship.

A NASA study shows that global warming decreases the amount of phytoplankton, the microscopic plants that underpin the ocean food chain. This delivers a double blow. It decreases marine populations, including fish stocks. It also contributes to global warming because phytoplankton absorb carbon dioxide from the atmosphere.

Your mind and your brain aren’t always on the same page. An experiment using a magic trick shows that the success of the illusion depends on social cues. The magician’s gaze and head movements convince us that a ball vanishes in the air, even though our eyes are not looking where we think we see the ball disappear. The research supports the notion that perception and vision are separate systems.

They say that people who get rich tend to forget where they came from. It looks like this is a scientifically valid observation. A series of experiments shows that money makes people less helpful and makes them prefer to play and work alone and keep their physical distance.