I award 10 points for original thinking!

I have a friend who became a professional tropical fish breeder. She observed similar trends in her fish tanks.

I am currently going through a book called "The Yugas". This book really challenges contemporary thinking on pre-history. The authors claims that humanity has been civilized for thousands of years. But these civilizations were "light on the environment", which means they did not leave a big footprint for us to find. And they were not so crowded either. Yet they had their philosophers, scientists, and mathemeticians. And they travelled the world sharing ideas.