The key is the phrase "for all intents and purposes", what he is trying to say is that we have as little idea behind what those early humans were like as we do aliens from another planet. He's not saying that aliens created the art. This is what happens when you read the Daily Fail. Wrong conclusions in the article and quotes taken out of context. The article tries to make it an ancient aliens connection. Not the book or scientist.
If these were really ancient depictions, I'd wonder about the skirts the figures are apparently wearing. OTOH, this is not the isolated and protected inside of a cave, so I'd presume that wind, sand and rain would have erased those paintings a longer time ago, i.e. this rather looks to me like recent Nigerian art. Bob
Yeah, the notion that the writer is in any way suggesting or endorsing the notion that these things were created by aliens is an hysterical misreading of simple English.
Just finished watching When Aliens Attack on NatGeo. That was some stupid shit. They kept pointing to the Afghan rebels beating the Soviets but neglected that the U.S. was feeding them weapons.
The concept of ancient aliens as presented on the show is complete bullshit, but like werewolves and vampires, it makes for entertaining TV.