Chapter 1–PEOPLE OF THE LAKE
The first chapter sets the scene for the book in the Miocene period in Kenya. It is a region teeming with wildlife that will eventually die and become fossilized due to the favorable conditions for fossilization in the Lake Turkana basin. Leakey and Lewin introduce the Koobi Fora camp site and describe the lake as it would have appeared millions of years ago, standing 200 feet higher as a source of the Nile river.
An image is presented of small, human-like creatures and their day-to-day interaction with their environment, which includes making tools, scavenging for meat, communicating, and touching each other frequently. It is a snapshot of an early hunter-gatherer community.
The authors go on to mention that many fossils have been found in this area, and put forth an estimate that between thirty and fifty million hominids must have lived in the geological corridor that runs from the Hadar, past Lake Turkana, down to Olduvai.
Chapter 2–A QUESTION OF SURVIVAL
This chapter focuses on important concepts that will be developed further as the book goes on. The authors mention some early findings from the camp that have allowed them to utilize taphonomy to help gather clues about the physical appearance of some early hominids. They are sure to mention that the conclusions they draw are based purely on inference, as many of the topics they explore throughout the rest of the book are all but impossible to confirm for certain.
Answers to come include why hominids started eating meat, the development of stone tools, the origins of language, the nature of man as it relates to violence and warfare, and more.
Chapter 3–IN THE BEGINNING
Despite a small amount of supporting fossil evidence, the authors are able to assert that three ape-like creatures lived around 15-10 mya. These are Gigantopithecus, Sivapithecus, and Ramapithecus. Ramapithecuse, according to Leakey and Lewin, is the most likely candidate to be considered the first true hominid. They were small and were likely never far from trees as they still possessed many arboreal characteristics. The discovery of these pre-human creatures led to a large-scale reclassification of the Miocene apes.
They speculate as to whether or not Ramapithecus was bipedal or quadrupedal, and decide that they can not be certain, but are certain that this shift took place sometime before the first reasonable hominid fossils appear around 3 mya. They also mention the likelihood that Ramapithecus had a very early form of tool use as a means to gain access to food. They were almost certainly a social animal, whether for protection, education, or some other external force. They also exhibited sexual dimorphism, with the males double the size of females.
Ramapithecus did not develop a taste for meat at this time, as their teeth were far better suited for food that was more accessible while living in the fringes of the forest.