When Did Prehistory Begin?

Historians had no difficulty in marking the end of prehistory as it happened when humans invented writing, the time of the first handwritten ( hand-drawn?) relic in history.

Recorded history is supposed to have originated with the invention of "writing" around 4000 BC in geographically distant regions of the world:

The ancient Sumerian Kingdom in what was later came to be known as Mesopotamia and is now the modern Iraq.

Egyptian hieroglyphics appeared at least eight centuries later.

Pre-Columbian logographics in Latin America including Olmec, Zapotec, Mayan and Aztec date down in history one to three millenniums later.

Yes, until we unearth any written or drawn document older than 4000 BC, that was the period when prehistory ended.

That brings us back to the other question:

When did prehistory begin?

Defining the beginning of prehistory was not that easy since it could literally mean the beginning of our Universe.

But, that meant much of prehistory would have been out of bounds for humans, being shrouded in mystery. And it would have remained so until human race disappeared from the face of this planet.

(Human race becoming extinct, really? Am I kidding? Unfortunately, the recent Japanese nuclear reactor explosions and the fallout are a foreshadowing pilot model of how our human race will end through celestial incidents a few millenniums from the present. That discussion on our future is better reserved for another article. Back to prehistory.)

For practical purposes, the beginning of prehistory has been set arbitrarily.

One broader definition says prehistory began with the appearance of "life" on this planet. Such a beginning should be of interest to biologicians and scientists in general.

For history buffs, this was still an elastic definition, stretchable by imagination. So, they restricted the beginning of prehistory to the appearance of the present human race on earth.

The human genus, the Homo, is thought to have appeared on earth some 2.5 million years before the present. The only surviving species of that genus, the Homo sapiens appeared 200,000 years ago.

Such defined limits of prehistory also became convenient in further dividing it into three "ages" (approximate earliest beginning dates given in brackets):

Stone Age (2,000,000 BC)
Bronze Age The Bronze Age (3500 BC)
Iron Age (1500 BC).