WHERE DO WE COME FROM?

We have a pretty good idea of the role eating meat has played in human evolution. In 1999, researchers at the University of California, Berkeley, revealed that early humans were eating animal meat 2.5 million years ago, confirming a lot of the research conducted over the past century about the relationship between human evolution and animal protein.

A meat-based diet was the norm rather than the exception when you look back to the dawn of man. It was nutrient-dense animal protein that helped early humans find enough nutrition and energy to evolve from being instinctual and living in the moment to being sociable, intelligent beings, capable of recognizing patterns, planning outcomes, and better controlling their environment.

In fact, the theory is, without an animal-protein-rich diet, we probably wouldn't have evolved into what we are today. A plant-based diet simply didn't have the complexity and density of nutrition that our bodies needed during that critical transformation period to develop our brains and to help the human body itself evolve.

In the last two centuries, scholars across the board — in evolutionary biology, paleontology, and epigenetics — have taken great pains to perfect their research methods. Thanks to their work, today, we know a lot of the details of how the natural environment, dietary habits, and behavioral factors led to the development of our species. It is through this knowledge that we can gain a profound appreciation for the power of food and our relationship to our environment to help each of us make wise choices about our individual approach to food.

Scientists from the fields mentioned have studied and continue to study life and the cultures of past generations, from the moment human beings first appeared on earth and began to produce simple tools to the present day.

The scope of their work covers an unusually broad range of time (millions of years) and space (the entire planet, both on land and in the watery depths) and is, at times, general (former societies and human groups) and anonymous (without the identity and concrete nature of names and languages).

As a result of this approach to the origins and development of our species, an enormous amount of in-depth knowledge has been gained on the subject, along with a detailed picture of the conditions under which we came into being as people: Homo sapiens.

For us, the most interesting age is the Quaternary Period, as the history of the birth and development of humankind is tied to this period. This is the period of anthropogenesis, or the formation of our species. Humans did not come into existence on earth as fully formed, perfected beings with all the psychological and physical characteristics we know today.

It was over the course of seven million years of evolution that humans laboriously and persistently made their way from imperfect forms that threatened their survival toward more perfect ones guaranteeing us safety, health, and further development.

The research irrefutably demonstrates humankind's evolution from animals and our genetic ties to primates, which first appeared on earth seventy million years ago. To this day, scientists disagree over the classification, taxonomy, and chronology of the genesis and evolution of humankind.

However, they do agree that ten to fourteen million and six to seven million years ago, the beings known as hominids — all anthropoid apes and our precursors (large, tailless primates) — branched out into several species. There is thus a close genetic relationship between large apes and humans (98 percent of our DNA is shared with large apes). The first beings to clearly differentiate themselves by their characteristic upright posture are members of the genus Australopithecus.

Australopithecines first appeared in East and South Africa in the Rift Valley lake region. An expedition by French and American paleoanthropologists discovered fifty-two bones of a young female skeleton there. Finding them at the height of Beatlemania, they gave her remains the name Lucy (Australopithecus afarensis) — the heroine of one of the rock group's songs. Her anatomy indicates that she is closer to chimpanzees than to contemporary humans.

This prehistoric beauty is a bipedal being who walked nearly upright on two legs and had strong neck muscles, long arms, and short, massive legs. Lucy is about twenty years old, weighing 30 kilograms (66 pounds) and standing 120 centimeters tall (slightly under 4 feet). Her small head sits practically on her shoulders, and her brain takes up 400 to 550 cubic centimeters (about 24.4 the 33.6 cubic inches) of the capacity of her skull, which is only about 20 percent of that of Homo sapiens. Lucy had mainly a plant-based diet, including leaves, fruit, seeds, roots, nuts, insects, and some small vertebrates, like lizards.

Our genus Homo split off from Australopithecus something like two million years ago, and a group of three Homo species (ergaster, rudolfensis, and habilis), along with another hominid (Paranthropus aethiopicus) appeared. Paranthropus was a vegetarian, our immediate ancestor H. ergaster, known as H. erectus, clearly ate meat.

Homo erectus stands up straighter and has a larger cerebral cortex. Its head is supported by its spine, and neck muscles that it no longer needs to support its cranium disappear. Its upper limbs become freer due to its vertical position, and it skillfully uses them to make tools. Encephalization allows the size of its brain to reach 1,000 cubic centimeters (about 61 cubic inches) of the capacity of its skull,8 and H. erectus was able to use this development to create a higher level of cultural progress.

H. erectus used universal flint tools — hand axes — to dig up edible roots from...