Unit 2
Human Diet and Evolution

Overview

It may seem a little incongruous that a course on nutrition should include the topic of the human diet and evolution. However, a little thought on the subject shows that this topic is, in fact, highly relevant. It is an axiom of biology that each species is well adapted to the environment in which it evolved. Indeed, we can still see clear evidence of our adaptation to the natural world. Our bodies are adapted to a force of gravity of one g, to all but the most extreme temperatures found on earth, and to the composition of the air. Our eyes are most sensitive to yellow, the colour of sunshine, and work well at all levels of light intensity, from bright sunshine down to weak moonlight. We may all feel at home in the early twenty-first century, with its myriad comforts, but biochemically and physiologically, we are creatures of the Stone Age. It follows, therefore, that the diet for which we are best suited is the one that was eaten during that epoch.

In this unit, we examine the diet eaten during the paleolithic period, and discuss its implications for the dietary requirements of modern humans. The paleolithic period, the “Old Stone Age,” lasted for hundreds of thousands of years, constituting a major part of the period of human evolution. In brief, the paleolithic diet was high in dietary fibre, but low in fat, saturated fat, and salt. We will discuss the paleolithic diet in greater detail in this unit.

Objectives

After completing this unit, you should be able to

1. describe the diet typically eaten by humans in the paleolithic period.
2. compare the paleolithic diet with the modern human diet.