The ochre hashtag art found in Blombos Cave. img src: Craig Foster
73,000 years ago in South Africa, someone took up an ochre crayon and made what appears to be a hashtag. As art, it's not terribly impressive to the modern eye. The design is very abstract and we have no idea what the symbol meant to the individual who made it. However, it's very existence is a profound find. Why? Because it predates the only other known art made by human beings by 30,000 years.
Why is this significant?
Besides the age, this is significant for a few reasons. There has been a long standing debate when people became thinkers like modern people are. The origins of abstract thought, symbolism and critical thinking are largely unknown. When did we become intelligent in the modern sense? Not just able to make tools, but to create symbols and art. That has been largely unknown and hotly debated.
Neandertal Cave Art in Spain. img src: P. Saura
It was thought for a long time modern human beings alone were the sole originators of 'art.' However, finds of Neandertal art have been appearing for the last twenty to thirty years. Unless both Neandertals and modern humans developed the capacity to create abstract art, to conceptualize abstract ideas, it seemed likely the ancestor of both had the capacity and probably did so. The idea is that if both of your kids do something, you probably did it, too.
There was some idea Neandertals might have picked up art from modern humans when they came through into Europe and elsewhere, but it appears the oldest Neandertal cave art predates modern humans coming into Europe by 20,000 years. That cave art seemed to have been the oldest out there. Older than anything modern people did by a time longer than what separates us from the beginning of the iron age in India, King Solomon in Judea, the founding of the Kingdom of Ethiopia by Menelik I, or the Zhou dynasty of China. That made it possible, in theory, for Neandertals to have figured out abstract thought and 'thought' modern humans.
Then, lo, a new surprise.
The Blombos cave in South Africa. img src: Magnus Haaland
The hashtag art with an ochre crayon is anything but impressive to our eyes, but its date is. The sediments in the Blombos cave in South Africa where the art was found are 73,000 thousand years old. That predates other modern human art by 30,000 years! It also predates the Neandertal cave paintings by 8,000 years. The distance in time and over land make it unlikely the South African tradition would have influenced the Neandertal. That would strongly imply our mutual ancestor had the capacity to think abstractly, in a modern sense.
Now an interesting side bit is, at Gibraltar, a cave where Neandertals lived also had a hashtag carved into the rock. That would be after modern people arrived in Europe. It is probably a coincidence: very few things have the same meaning across 2,000 years in recent history, never mind 30,000 years. However, you have to wonder what the hashtag meant back then. The symbol definitely has taken on a particular meaning today, though. But then, you are trying to interpret abstract art from peoples who might be relatives, but had wildly different lives. Abstract art from people today is hard enough to understand.
An abstract drawing from the 73,000-year-old levels at Blombos Cave, South Africa
https://www.nature.com/articles/s41586-018-0514-3
Multimedia graphic design -- 73,000 years ago
https://www.eurekalert.org/pub_releases/2018-09/uotw-mgd091118.php
Neanderthal artists made oldest-known cave paintings
https://www.nature.com/articles/d41586-018-02357-8
Ancient Hashtag Is Oldest Drawing Yet Discovered
http://blogs.discovermagazine.com/d-brief/2018/09/12/ochre-hashtag-blombos-cave-drawing/#.W5qms5NKjBJ
Oldest-known drawing found in South African cave
https://newatlas.com/oldest-human-drawing/56297/
40,000 Year Old Neanderthal #Hashtag Engravings from Gorham’s Cave in Gibraltar
https://anthropology.net/2014/09/02/40000-year-old-neanderthal-hashtag-engravings-from-gorhams-cave-in-gibraltar/
A rock engraving made by Neanderthals in Gibraltar
http://www.pnas.org/content/early/2014/08/27/1411529111