Peer review other scientist will check the findings before it gets published
<span>Around 2.4 billion years ago, the first photosynthetic organisms appeared and used inorganic matter like carbon dioxide and water to produce glucose, with oxygen released in the atmosphere. Because of this, oxygen levels rose; this is called the <em>Great Oxygenation Event</em><span><em>.</em> Through time, photosynthetic organisms evolved to live in land (now as plants). As concentrations of oxygen in the atmosphere became higher, marine animals evolved to utilize oxygen readily available from the atmosphere (rather dissolved in water) hence the evolution of marine animals to land animals capable of respiration in land. </span></span>
Pluto
Nasa's New Horizons mission made a close pass of Pluto this week. For more than 70 years, Pluto was one of nine planets recognised in our Solar System. But in 2006, it was relegated to the status of dwarf planet by the International Astronomical Union (IAU)
