Speedy ocean predators change their skin colour to signal they’re going in for the kill (1:02)

Marlin are predatory fish that can reach tremendous speeds in pursuit of food, making collisions between them potentially deadly. A new study has shown that the fish display bright and vivid skin colours to signal to other marlin when they’re attacking prey, so as to avoid butting heads. Alicia Burns and her team from the Science of Intelligence Cluster, Humboldt University used drones to capture video footage of the marlins’ hunting behaviour.

The tiny genetic fluke that led humans — and other great apes — to lose our tails (9:15)

Back when in our evolutionary history, a fragment of genetic material accidentally found itself in in a gene long been known to be important for the development of our entire back end. The result of this mutation, according to a study in the journal Nature, was that we and our great ape ancestors lost our tails. Itai Yanai, a cancer biologist from New York University Grossman Medical School, identified the mutation and found when they duplicated it in mice, they also lost their tails. 

A cannibal star shows signs of its last meal (18:06)

Astronomers have identified a nearby white dwarf star with what they are calling a ‘scar’ of material visible on its surface. This was probably an asteroid flung towards the star, ripped apart by its gravity, and its rubble drawn onto the star’s surface by its powerful magnetic field. This is the first time such a phenomenon has been seen. This study was conducted by a team including astronomer John Landstreet, a professor emeritus from the Physics and Astronomy Department at Western University.

Stone age craftsmen acted like engineers when selecting materials for their tools (26:32)

A new study of what it takes to make efficient and effective stone tools, like the ones ancient humans were producing back in the Middle Stone Age, shows how discriminating they were in the materials they selected. Patrick Schmidt, an archaeologist from University of Tübingen, published a study in the journal PNAS about a model he developed to assess how well suited the raw materials were for the type of tools they were creating. Schmidt said their findings suggest that stone age craftsmen had an engineer’s understanding of the mechanical properties of the materials they used.

Boreal forest on the move — the past, present, and potential future of the ‘lungs of the planet’ (35:39)

The boreal forest has an important role in maintaining a healthy planet, by storing carbon, purifying the air and water, and helping to regulate the climate. Researchers are using novel ways to understand how the boreal forest has changed over time, to help predict how it can change in the future.

Paleoecologist Sandra Brügger traced a detailed history of the forests in Eastern Canada over the past 850 years by studying trapped pollen found thousands of kilometers away in the Greenland ice sheet. The ice cores allowed the team to look at the shrinking and expansion of the forest since the Little Ice Age, and spot the effects of humans as they took over the landscape. The research was published in the journal Geophysical Research Letters.

Then, by doing detailed analysis of trees along the Brooks mountain range in Alaska, a team of researchers including Colin Maher discovered a link between retreating sea ice and an expanding Boreal forest. When the sea ice disappears, the open water generates more snow, which not only blankets the landscape and protects the young seedlings, but it also helps the soil unlock more nutrients for the growing trees. The research was published in the journal Science.