Here's the deal ... on Thursday, an apparent Bigfoot made its TikTok debut ... recorded just chilling against a tree in a wooded area of Lawton, about 3 hours from Oklahoma City. It was quickly dismissed as an obvious fake -- but it also piqued some legit new interest!

Dr. Jeffrey Meldrum, a professor of anatomy and anthropology at Idaho State University, tells TMZ Bigfoot finding such a popular foothold in pop culture is a double-edged sword … 'cause it does poke fun at those who truly are investigating its existence … but the silliness also encourages more people to ask questions.

The author of “Sasquatch: Legend Meets Science” says the existence of a Bigfoot creature is “one of the most interesting questions facing researchers of human evolution” … so there’s a lot more to this than just selling beef jerky, and stooges trying to get clicks.

Dr. JM says he has “hundreds” of legit foot casts of sasquatch and other relict hominoids from around the world … so he is quite confident something was -- and may still be -- out there.

It is easy for skeptics to point to prank videos like the recent one, and to snack commercials, to mock the idea … but if people look at the actual evidence, their tune would change pretty quickly.

Of course ... he points out discoveries of actual evidence rarely make news … people acting like boobs with fake videos are more fun for the media to cover.

As for the popularity of Bigfoot over other mysterious creatures ... Dr. Meldrum tells us that is born out of nationalism. The term "Bigfoot" was coined in the U.S. in 1948, and it became “our monster” … and from there, creatives ran with the idea for sci-fi.