The book's extensive teachings about the history of the world include its physical development about 4.5 billion years ago, the gradual changes in conditions that allowed life to develop, and long ages of organic evolution that started with microscopic marine life and led to plant and animal life in the oceans, later on land. The emergence of humans is presented as having occurred about a million years ago from a branch of superior primates originating from a lemur ancestor. The first humans are said to have been male and female twins called Andon and Fonta, born "993,419 years prior to 1934."