Thanks for your question. It depends what you mean by humans. Our ancestors were around as long as 6 million years ago, but the more modern humans appeared 200,000 years ago. They say humans (Homo sapiens) evolved during the Cenozoic era, or “The Age of Mammals”. There used to be a lot less of us. To put in perspective, it took 200,000 years to reach 1 billion people but only 200 years to reach 7 billion! They now think we have around 7.7 billion people as of April 2019.