Dickinsonia costata, a typical fossil of the Ediacara biota

An article published in the journal “Nature” in December is causing discussions among paleontologists. The reason is that according to Gregory Retallack, a geologist at the University of Oregon in Eugene, life on land began 65 million years earlier than is generally estimated.

Rita Levi Montalcini in 2009 (Photo Presidency of Italian Republic)

Rita Levi-Montalcini, neurologist and since 2001 senator for life in the Italian Parliament, passed away today. Born on April 22, 1909 in Turin, Italy, for her discovery of the Nerve Growth Factor (NGF), in 1986 she received the Nobel Prize for medicine.

In December 2010, the discovery of a bacterium called GFAJ-1 in Mono Lake in California caused quite a sensation. The scientists who studied it declared that it was capable of using arsenic instead of phosphorus among the basic elements of its biochemistry. Now two new studies disprove that this bacterium uses arsenic in its DNA.

The Viking 2 on Mars at Utopia Planitia in 1976 (Image JPL/NASA)

In 1976, the Viking 1 and 2 landers carried out an experiment on Mars that aimed to test the possibility that there was life on the red planet. Some chemical reactions revealed were unexpected but they weren’t regarded as evidence of the existance of life forms. The issue remained controversial and now an international team of scientists who conducted new analysis on the data from that time concluded that probably there’s life on Mars.