The entire human population of Earth was less than 26,000 for about 1
million years.

According to scientists from the University of Utah, the entire human
population of Earth was less than 26,000 for about a million years. Even
fewer, about 18,500, were capable of breeding. This means that 1.2 million
years ago, humans were an endangered species. Endangered species are
species at risk of becoming extinct.