It is now accepted that the first cells derived from simpler "objects," and that their descendants became more and more complicated and ordered until their evolutionary transformation into modern cells, namely, cells endowed with the same basic structures and mechanisms as those existing today. Although the appearance of the first modern cells goes back at least two billion years, many scholars believe that it occurred almost four billion years ago. In that case, the Earth's formation, which took place quite quickly about 4. 6 billion years ago, is in close proximity to the originoflife....