Observation
Every atom of every person that ever died is still on this planet
Except for those few that escaped into space (mostly hydrogen), or those that were unlucky enough to get caught up in a nuclear reaction, or just underwent natural radioactive decay.
The corollary is that 100% of the atoms in our bodies have previously belonged to other organisms.
GPT helpfully adds this:
The first part is essentially right, with these qualifications.
The corollary is too strong. Nearly all atoms in our bodies have almost certainly previously participated in other organisms, but “100%” cannot be established and is probably literally false. Some atoms will have entered the biosphere relatively recently from rocks, the atmosphere or other reservoirs without previously being incorporated into life.
The stronger observation is:
> We are not materially distinct from previous life. The atoms are continuously recycled; what distinguishes an organism is their temporary organisation.
Estimated correctness: 0.98
offshore westerly 