Origin & Evolution of Life: October 2013

Any textbook will tell you that oxygen is essential for advanced life to evolve. But why did life not explode when oxygen levels rose dramatically 2.1 billion years ago? This is the big question after a Danish/Swedish/French research team, led by University of Southern Denmark, has shown that the oxygen content 2.1 billion years ago was probably the same as when life exploded 500 million years ago.

Finding life on exoplanets may be more difficult than people thought, said Feng Tian, a professor at the Center for Earth System Science at Tsinghua University in Beijing, China. The report is being presented today to the American Astronomical Society Division for Planetary Sciences meeting in Denver, CO. The result is of special interest because it may shed light on how and where life could be identified on exoplanets.

The mystery of why life on Earth evolved when it did has deepened with the publication of a new study in the latest edition of the journal Science. Scientists at the CRPG-CNRS University of Lorraine, The University of Manchester and the Institut de Physique du Globe de Paris have ruled out a theory as to why the planet was warm enough to sustain the planet's earliest life forms when the Sun's energy was roughly three-quarters the strength it is today.