It may have appeared 2.2 billion years ago based on new fossils: > > http://www.sciencedaily.com/releases/2013/07/130722141548.htm-Complex organisms at 2.2-2.8byn, more than half the age of the earth. On one side, it is closing the time frame that life had to come into existence, on the other, it is extending the time frame that life had to 'evolve' according to the current model of evolution. Strangely though, it presents another interesting problem. If life existed 2.2-2.8byn ago, why did large life only crop up in the last tiny fraction of that time?