ManusJustus on 30 April 2010
| Slimebeast said: If it's so likely that there's life on other planets, then why did life only happen once on our planet? If the conditions for life here are so great, why did life only started precisely once in 6 billion years? |
Life regularly recycles organic compounds, so any other 'formations' of organic molecules would quickly be consumed by existing life.
Still, it appears that other forms of life did form. Mitochondria have their own DNA, and it is widely believed that they once lived on their own, but the cell as we know it today consumed the mitochondria and uses it for its own purposes. Just read up on the Endosymbiotic theory. Also, there are 'different life' theories on the origin of viruses.
