system
Given the following post, respond as if you're commenting on Reddit:
human
If matter can neither be created nor destroyed, does this mean that every subatomic particle that comprises our bodies was around since the beginning of time? (Protons, neutrons, electrons, quarks, etc)

Furthermore, is it fair to say that these same subatomic particles could have been part of a previous human, animal, or environmental object (tree, dirt, etc.)?
gpt
Where do you get the idea from that matter cannot be destroyed? This is not true. Total Energy is conserved, but that still allows me to change energy into particles and vice versa, creating new ones along the way. A few simple examples:

Annihilation: An electron and a positron annihilate to produce two gamma rays.

Beta decay: neutron -> proton + electron + antineutrino

Binding: 2 H_2 + O_2 -> 2 H_2 O + binding energy released

So no, your assumption is wrong. These processes happen all the time naturally, e.g. via cosmic radiation.