Chapter 3: Let’s Make a Knife

The men who were the better hunters and more aggressive would not necessarily become leaders… hunting does not explain our lineage’s success.

“Active and organized hunting shows up pretty late in our evolutionary trajectory- scavenging, gathering, and innovating with diverse foods all precede it. Being hunted rather than the hunters is the reality at the start of our lineage, and gender differences associated with food that we see today are not evident in our deep past” (51) 

Top Chef

Food stress was a huge problem for early Homo. They had to get creative to develop food options! Early Homo made sharp stone flakes and hammer stones, collaborated, watched how other animals got their food and mimicked them. Researchers found evidence in Kenya from 1.9 mya of turtle shells cut with tools and filleted catfish. This food source variety increased chances of survival. Advantages associated with new food habits include reduction in the energy it takes to acquire and process nutritionally rich food, reduction in competition with other species, and decrease in the danger of scavenging carcasses.

Getting an Edge

The most nutritious meal is one with a perfect mix of macronutrients and micronutrients. Humans learned to forage, hunt, and cook in a special way to make this diet possible.

The Homo lineage was the most creative with its tool use, and chimps were the second. Chimps selected specific rocks to crack nuts, chose large sticks to break open termite mounds then small sticks to fish out the termites, and used leaves to drink from streams. They could tell that there was a difference between the shapes of rocks and sticks that made them better or worse tools!

Stone making was first seen in our lineage 2-3 mya and it greatly improved our ability to access food. Stone making required much collaboration and creativity, much more so than selecting an unmodified stick or stone. The oldest and simplest stone tools come from the Oldowan industry in Tanzania (first seen 2.5 mya) and more complicated tools came later in the Acheulean industry (first seen 1.5 mya).

Oldowan tools are very impressive because they required knowledge of physics. The rocks were hit from particular angles to make the sharpest possible tool. The most common tool was a sharp stone flake created by striking a stone core (cobble) with another stone (hammer stone). Homo had to know what types and shapes of stone would make the best cobbles and hammer stones and also what location to strike the stone to make the best flake. They then had to pass this information along to others to allow Oldowan tools to be made in the next generations. Researchers at the University of St. Andrews and Emory University demonstrated that brain size and cognitive complexity actually increased because of tool making.

“The action of toolmaking, and the watching, imitating, and communicating about toolmaking, can set up and expand the activity and dynamics of particular areas in the brain- areas that we know began to grow between 2 and 1 million years ago, and areas that are eventually associated with language and other high-level cognitive behavior” (60-61) 

The Acheulean tool industry began 1.5 million years ago and existed until 250 thousand years ago. The technique of the early Acheulean era included removing smaller flakes on both sides with very specific strikes to make sharper and stronger edges. A hammer was then used to modify the stone further. This was a very complicated process and required much more visualization and planning than the Oldowan method. Collaboration was required to carry stones to the location of the prey, because 20-25 pounds of stone was required to deflesh and dehide a wildebeest! 

The Late Acheulean industry (700-250 kya) was even more complex than the early Acheulean. Hard, soft, and bone hammers were used.  Four to six pre-modifications were made to the core and many flake removals were required. This allowed for the diversification of tool types as well as sharper tools, which led to greater flexibility and efficiency when acquiring food.  

Oldowan and Acheulean tools improved human life for over 2 million years. These two tool cultures required much collaboration and creativity, and allowed for societal change. These tools increased nutrition, brain growth, creative collaboration, and manipulation of the environment. 

Avoiding Being Dinner

A tradeoff existed between eating better and more nutritious food and being eaten. Hunting was much riskier than foraging. Tool making was a loud process and attracted predators. But humans got creative and found a way to hunt, make tools, and still avoid being eaten. Dietary diversity and complex behavior developed as brain size increased, allowing for greater levels of creativity.