There is a lot wrong with this approach, but even if you agree with their method there is one thing that seems odd in their analysis. Let's suppose that life or

There is a lot wrong with this approach, but even if you agree with their method there is one thing that seems odd in their analysis. Let's suppose that life originated before the birth of the earth. Obviously it managed to reach earth, which would mean it (the organism) had to travel through space for an extended period of time - the authors claim that it was frozen - so you should account for that time in the graph, and obviously life couldn't settle on earth for quite some time because in the beginning our planet was extremely hot and unsuitable for any kind of life. That would shift their postulated origin of life further into the past, most likely to a point where there wasn't even a universe to begin with, or at least no planets that would allow for the formation of life. [Note: I didn't read the whole paper, maybe they discussed these points. Also please correct me if I'm wrong on anything]