All at once, over a 15,000 year period? Those cave paintings show that they were created over a very long period. Also, just because we haven't found anything older is not evidence that nothing was done before then.
I would argue that the existence of jewerly that is far older than any cave painting shows that the origion of the esthetic arts is truly primordial.
Now, about the "jewelry" ~ unless it's been handpolished, carved into a recognizable animal or human form, had a hole drilled in it to hang on a thong, it ain't art ~ just a shiny rock and even crows like shiny rocks.