Evolving brain

A team of biologists says that the evolution of human brain has been an ongoing process for the last several thousand years. Comparing modern humans with our ancestors 37,000 years ago, they discovered new variants of two genes which are responsible for changes in brain size, its complexity and intelligence, reports Science.

Smell route

nWhen harbour seals go looking for food, how do they frequent distinct feeding grounds over and over' Scientists in Germany speculate that they may navigate by smelling low concentrations of dimethyl sulfide, a gas produced by planktons, says Biology Letters. The seals know that planktons harbour lots of ‘foods’ around, in the form of fish.

Old methane

Analysing traces of methane trapped in air bubbles within 2,000-year-old Antarctic ice, scientists have found that levels of the gas rose steadily around the earth during the first millennium too. Most of the ozone layer-destroying greenhouse gases came from huge fires lit by humans as they cleared woods or grasses for settlements and farming.