Evo scientists contend that life began 3.8 billion years ago possibly around vents in the bottom of earth's oceans. According to this theory, life began when the first replicating molecules and cells appeared in or aroud these vents. Accordingly, this process is not now going on. It was an anomoly--a one time event?
If the previous conclusion is true, curent cells in all life forms (including humans) must contain unscathed copies of this original genetic material--a copy of a copy duplicated for 3.8 billion years (that's what constitutes life) . Incredible.
The human begins with one cell. At maturity the human body consists of 100 trillion cells. Moreover, the 100 trillion cells are replaced totally every ten years--with some cells living longer than others. When someone is 50 years old there have been over 500 trillion copies of their orginal one cell.
One theory of the cause of death says that copying errors occurring in cells eventually (genetic entropy) causes death.
3.8 billion years of genetic entropy would most assuredly have doomed life by now!
That leads to the conclusion that life on earth hasn't been here that long.