You might think that man began recycling operations sometime in the 20th century, but you would, in fact, be incorrect. So, when did humans begin recycling? The 1800s? Maybe the 1700s? Medieval times? Not even close. According to scientists at an environmental conference in Tel Aviv, Israel, humans began to recycle more than 20,000 years ago. That’s right: in the time of cave people.

Before there were plastics or stainless steel—even before the invention of the wheel—early humans practiced recycling techniques for the flint and bone that they used in everyday life to create new tools and utensils. In fact, the Associated Press reports that the more than 50 scholars who gathered at the conference came to the shocking conclusion that even our pre-human Neanderthal and Homo Erectus ancestors had some hand in recycling.

Tel Aviv University archaeologist Avi Gopher said that while he doesn’t feel that environmental concerns prompted ancient recycling efforts, the cave people did have some of the same incentives that we do today: Energy conservation and raw material conservation, to name the big ones. She also said that the earliest proof of ancient recycling—the reworking of flint from one usable tool to another—took place an astonishing 1.3 million years ago.

Gopher said that the behavior was not a sporadic or occasional one, either.

“It was part of the way they did things. Part of their way of life.”

What does this mean to us? First of all, that finding ways to work around human limitations or raw materials that may be in short or dwindling supply has been a top priority for multiple generations of humans. The fact that recycling is now considered to be environmentally friendly is just a recent development in modern times.  It has been a valuable part of human beings’ lives for as long as we’ve been on this planet. The need to recycle for the benefit of the planet may be new, but the act itself certainly isn’t.

If this teaches anything, it’s that recycling is not only here to stay: but it’s been here the whole time. Recycling as a part of waste management services, both on a small and large scale, is more than just important: it’s who we are as humans.