New evidence that life began MARs, hints that NASA should being focused in on MARS not Asteriod side missions2 Sep 2013, 21:01 UTC
New evidence presented by Professor Steven Benner at The Westheimer Institute for Science and Technology in Florida suggests that, billions of years ago, Mars was a much better place for the first cells to have formed compared to Earth. This gives more weight to the theory that life may have started on the Red Planet and then found its way to Earth aboard a meteorite.
Life on Earth
The fossil record tells us that life first appeared on our planet around 3.5 billion years ago, but we know very little about how the first cells came to be.
Scientists theorize that, as the Earth slowly cooled down, simple organic compounds (monomers) slowly formed and combined into more complex compounds (polymers). Then, as sea currents pooled these large molecules by "hotspots" like oceanic shores and hydrothermal vents on the sea floor, they may have eventually combined to form the first protocells.
However these building blocks combined, there is growing evidence that the first cells replicated using RNA instead of DNA, and that the switch to DNA replication, which is stabler but harder to achieve, happened only much later in the history of evolution. (One convincing piece of evidence for this ...