  In a recent paper [1] Lineweaver and Davis performed a statistical analysis
to claim that the rapidity of biogenesis on Earth indicates high probability of
biogenesis on terrestrial- type planets. We argue that the rapid appearance of
life on Earth hardly tells us anything about the probability of life to appear
on other planet. The conclusion should be different. The rapid initial
biogenesis is consistent with a large number ($N \sim 10$) of crucial steps in
evolution from simplest life forms to humans.
