Evolutionary anthropologists say Stone-Age people, who buried their dead,
were around for about 185,000 years, at a population between one and ten
million. If these numbers are correct, they would have buried at least
eight billion bodies, but we have found remains of only a few thousand.
That is more in line with an age of only a few hundred years before
history.
The fact that some people buried bodies does not mean all did. In many
cases, such as wars, plagues, natural disasters, and lone people
getting lost, people get killed without even any consideration of
funerals. Some land, such as swamps, hardpans, and ground frozen in
winter, makes burial impractical at best. Even today, common funerary
practices include incineration, exposure to the scavengers and
elements, and burial at sea.
Burial alone does not preserve a body.
In many acid soils, all organic matter can easily decay in 1,000
years. Hot, damp conditions in the tropics will also decay bodies
and leech bones quickly.
Groundwater, plant roots, digging animals, or a combination of
these can also speed decay to the point where nothing would remain
after a few thousand years.
Erosion or reuse of the land by humans may unbury the body, at least
to the point that the bones are subject to greater decay.
Sea level rise, volcanism, modern construction, or other processes
may make the land unreachable now.
All of these are significant factors. Fossilization is not a common
process. And we have examined only a tiny fraction of the land where
bodies might be buried. The few thousand remains we have found are
well in line with a 185,000-year human history.
We would not expect the burial of artifacts to be common. There would
be no reason to bury cheaper tools, such as pounding stones, with
people. More valuable artifacts would not likely be buried with poor
people.
