Around 10,000 BC there likely were only an average of 5 million people on earth: Why?

1. Because it is thought that we were more hunter gatherers then. And as hunter gatherers instead of farmers there was much less stability and efficiency regarding food and food preparation. So, birth rates and health were a problem likely then too. IN other words if you cannot count on regular food and you are being killed by neighbors also competing for food then you cannot grow as a family or tribe very much.

2. 
   

3. Around 10,000 BC there likely was an average of 5 million people on earth. Or it is thought between 2 milion and 10 million people worldwide. So, in the last 12,000 years things have changed a lot here on earth.

1. begin quote from wikipedia:

2. 10th millennium BC - Wikipedia, the free...