They try to put organism's compexity on a logarithmic scale and look where this line "reaches zero". Then they find out it was very very long ago, before the Earth coalesced. They then proceed to imply that life is older than Earth.
The problem here is: you can't do that.
For example, if you look at human population, it was growing kind of exponentially for as long as we know. And if we continue this trend long enough to the past we'll infer that Earth featured several dozens of humans even when it was still in a liquid magmatic state five billion years ago!
Exponential growth becomes glacially slow when we go back in time. Therefore, any growth seems to be not exp(t) but rather max(ct, exp(t)) - not slower than linear.
It doesn't matter once we hit present history, but it does matter when we talk about a linear part in the past.
The problem here is: you can't do that. For example, if you look at human population, it was growing kind of exponentially for as long as we know. And if we continue this trend long enough to the past we'll infer that Earth featured several dozens of humans even when it was still in a liquid magmatic state five billion years ago!
Exponential growth becomes glacially slow when we go back in time. Therefore, any growth seems to be not exp(t) but rather max(ct, exp(t)) - not slower than linear. It doesn't matter once we hit present history, but it does matter when we talk about a linear part in the past.