Even more dramatic, a number of genetic studies suggest that hominids faced near extinction more than once eg http://www.scientificamerican.com/article.cfm?id=e

Even more dramatic, a number of genetic studies suggest that hominids faced near extinction more than once eg http://www.scientificamerican.com/article.cfm?id=early-human-population-size-genetic-diversity http://www.scientificamerican.com/article.cfm?id=early-human... estimates a total population of around 50k.