[1] In the southeastern Pacific Ocean, on the piece of land known as Easter Island (now a territory of Chile), stand several hundred massive stone monoliths. These carvings, called “moai,” are recognizable by their oversized heads, heavy brows, long noses, elongated ears, and protruding lips. While they average four meters in height and 12.5 tonnes, the largest is almost 10 meters tall, and the heaviest weighs 86 tons. The upright sculptures are scattered around Easter Island, many installed on platforms called “ahu” along the coast, while others are more inland, and several stand near the main volcanic quarry of Rano Raraku. The Rapa Nui people of the island built a total of 887 of these impressive statues between the 12th and 16th centuries. They were, it is said, symbols of religious and political authority, embodiments of powerful chiefs or ancestors who faced inland toward the island’s villages, perhaps watching over their creators, keeping them safe. 

[2] While the very creation of such monoliths – most out of volcanic ash with stone hand chisels – is an impressive feat, what is more remarkable (not to mention mysterious) is how they were transported to their resting places. In the past, most researchers associated the building and transportation of the moai with widespread deforestation on the island and the eventual collapse of the Rapa Nui civilization. This hypothesis is based, in part, on the fact that the pollen record suddenly disappeared at the same time as the Rapa Nui people stopped constructing the moai and transporting them with the help of wooden logs. How exactly would logs facilitate the movement of the statues? Most proponents of this method believe that the people created “rollers” by arranging parallel logs on which the prone statues were pulled or pushed. They would not have required an entire roadway of logs since logs from the back could be placed at the front, creating a moving platform of sorts. To make it easier to roll, and keep in position, the statue would be placed on two logs arranged in a V shape. 

[3] One proponent of this idea of rolling the statues in a prone position is Jo Anne Van Tilburg, of UCLA. Van Tilburg created sophisticated computer models that took into account available materials, routes, rock, and manpower, even factoring in how much the workers would have to have eaten. Her models supported the idea that rolling prone statues was the most efficient method. As further evidence, Van Tilburg oversaw the movement of a moai replica by the method she had proposed. They were successful, but evidence that it was possible is not necessarily evidence that it actually happened. Van Tilburg was not the only one to have experimented with rolling the statues. In the 1980s, archaeologist Charles Love experimented with rolling the moai in an upright position, rather than prone, on two wooden runners. Indeed, a team of just 25 men was able to move the statue a distance of 150 feet in a mere two minutes. However, the route from the stone quarries where the statues were built to the coast where they were installed was often uneven, and Love’s experiments were hampered by the tendency of the statues to tip over. While Love’s ideas were dismissed by many, the idea of the statutes tipping over along the route was consistent with the many moai found on their sides or faces beside the island’s ancient roads. Local legend held that the statues “walked” to their destinations, which would seem to support an upright mode of transportation. In fact, rolling was not the only possible way of transporting the moai in an upright position. 

[4] In the 1980s, Pavel Pavel and Thor Heyerdahl had experimented with swiveling the statues forward. With one rope tied around the head and another around the base, they were able to move a five-ton moai with only eight people, and a nine-ton statue with 16. However, they abandoned their efforts when their technique proved too damaging; as they shuffled the statues forward, the bases were chipped away. This confounding factor led most to believe that an upright, rope-assisted walking method was incorrect. 

[5] But many now believe that they were, in fact, transported upright. In 2012, Carl Lipo of California State University Long Beach and Terry Hunt of the University of Hawaii teamed up with archaeologist Sergio Rapu to refine the upright walking idea. They found that the statues that appeared to be abandoned in transit had bases with a curved front edge. This meant they would naturally topple forward and need to be modified once they reached their destinations. But that curved edge also meant they could easily be rocked forward using a small team of people and three ropes attached to the head. Indeed, their experiments demonstrated the feasibility of this method, and their theory has gained traction. 

[1] While the use of stone tools began 2.5 million years ago, it wasn’t until about 10,000 BCE that Homo sapiens applied these tools to the deliberate cultivation of plants and animals. The adoption of sustained agriculture – what anthropologists call the “Neolithic revolution” – signifies an important turning point in the development of human societies, as it led directly to population growth, permanent or semi-permanent settlement, as well as technological and social development.

[2] Neolithic agriculture developed at different times in different parts of the world, beginning with the Levant and Mesopotamia, followed by Northern Africa, Southeast Asia, and Europe. But while we often call it a “revolution,” it would be a mistake to believe that agriculture was a sudden and complete development, an all or nothing proposition that societies adopted wholesale at the first opportunity. Instead, it developed slowly, beginning as a supplement to more traditional hunting and gathering lifestyles in which people relied on plants and animals gathered or hunted in their natural environment. Over time, as people learned more about and relied more greatly on domesticated plants and animals, they settled more permanently and cultivated the land more intensively.

[3] Neolithic farmers collected and planted seeds that they learned would produce palatable grains, selectively breeding plants deemed healthy and delicious and avoiding those not. Early agriculture was restricted to a limited number of plants, namely Emmer wheat, Einkorn wheat, and barley. Later, people learned to cultivate pulses, including lentils, peas, chickpeas, bitter vetch, and the multi-purpose flax plant. These eight plant species are known as the Neolithic founder crops or primary domesticates.

[4] People’s success in planting, cultivating, and harvesting these plants came about as a result not only of their increased knowledge of the plants themselves but also of the conditions for growth. They explored innovative irrigation techniques, which enabled even greater production and, eventually, food surpluses. Of course, food surpluses are useless unless people have the ability and facilities to store them, which people did in granaries. And food surpluses, in turn, enabled a host of other social developments, like occupational specialization (since not everyone had to be involved in food production), trade, and social stratification.

[5] These advances in agriculture went hand in hand with technological development. People fashioned stone tools such as hoes for working soil, sickle blades for harvesting crops, and grinding stones for processing grains. However, the polished stone axe was more important than such agricultural implements, which allowed the Neolithic farmers to clear forests on a large scale and open up new lands for cultivation. Along with the adze, the axe also enabled them to work the trees they felled into wood that was usable for building shelters and other structures.

[6] Besides cultivating plants, these stone-age farmers also domesticated animals. At first, it was sheep, goats, and dogs whose temperament, diet, and mating patterns made them good candidates for domestication. Later, cows and pigs were added to the mix. Besides meat, these animals provided people with milk (a renewable source of protein), leather, wool, and fertilizer. Cows became valued for their labor, as they assisted with plowing and towing, and dogs provided protection (not only to humans but also to their crops and livestock) as well as companionship.

[7] That agriculture enabled hitherto unknown population growth is undeniable. Food surpluses and an agricultural lifestyle brought security and safety that nomadic hunter-gatherers did not enjoy. And it may be argued that the subsequent advances in all realms of society – not only the aforementioned technology but also knowledge, art, writing, and astronomy – would not have emerged without a sedentary lifestyle. But the impact of the Neolithic revolution, often heralded as a giant step forward for humankind, was not all positive.

[8] Sedentary agriculture narrowed the diet of Neolithic peoples: they consumed greater amounts of starch and plant protein and fewer types of food overall. An increasing number of researchers claim that human nutrition worsened with the Neolithic revolution. In addition, the disease increased as humans lived in closer contact with each other and with domesticated animals; sanitation didn’t advance quite as quickly as agricultural methods. It also turns out that agriculture required significantly more labor than hunting and gathering. The combined result of these facts was a life expectancy that was most likely shorter than that of the apparently more primitive hunter-gatherers.