[electromagnetic]

You're correct and these "art started xx,000 years ago" are kind of laughable.

Yes the first instance of preserved art is from that date. However, it's a fossil. Do we assume our ancestors sat around the camp fire suddenly decided "hey I'm going to take some berries and plaster them on the wall in the shape of a deer". No one before that took a stick and drew in the dirt?

We're also oblivious to huge amounts of human history. Neanderthals are thought to have lived in groups of about 50 people and there's evidence of them living in everything from open air camps to huts.

What these paintings could well be showing us is merely a record of what they've seen in the area. When you're nomadic it was likely beneficial to leave a reminder of what you hunted in the area.

I expect art started in the Neanderthals, there's evidence they may have practiced medicine. They made tools. It makes sense modern humans would have learnt and improved it like we did everything else.

We took huts and made longhouses. We took fur clothing and sewed them into clothes. We took spears and darts and made atlatl and bows. Why wouldn't we have taken Neanderthals scratchings in the dirt and probably on rocks and we made permanent paintings on the walls with colour and detail.