A barrage of tests proves that the marijuana possessed potent psychoactive properties and casts doubt on the theory that the ancients only grew the plant for hemp in order to make clothing, rope, and other objects. Lead author Ethan Russo told Discovery News that the marijuana "is quite similar" to what's grown today.
(Source) In 2007, a 5,000-year-old piece of chewing gum, the oldest ever discovered, was found by a British archaeology student in Finland.
Another site in Oregon, Paisley Cave, is considered home to the earliest known residents of North America based on human physical evidence. Dennis Jenkins, discovered coprolites - fossilized feces - containing human DNA dated over 14,000 years old.
Scott Thomas, the BLM archaeologists, says the small number of sites more than 13,000 years old and the lack of skeletons make it difficult to draw conclusions about pre-Clovis culture.
“These theories are actually multiplying about how people got here, not getting tighter, with all these new discoveries,” Thomas said.
“We have this intriguing piece of evidence that says this site is among the oldest, but we still have a lot of work to do,” O’Grady said.
The team has one more clue about the knife’s origins.
The other edge has a steep, flaked edge that could have been used to scrape hides and cut meat off of bones.