of the oldest houses known from northern South America.
The dwellings at El Porvenir exemplify the archaeological evidence of home. First, the evidence we found in our excavations bore the imprints of human intention. The post-molds were evenly spaced and aligned, well-made pits; they were neither root bores nor animal burrows. In the upper layers the floors were made from thick caps of grey river clays and the lower floors were compacted midden; both were human made. These were cultural features, not natural products, and they reflected a plan. They were, to recall Tim Ingold’s observation, a human project.
Second, people carried things to these dwellings, a point so obvious that it is easily overlooked. People transported shellfish and fish, pottery and stone tools to these places—moving these materials kilometers, bringing these things home.
Finally, each of the dwellings contained the traces of a suite of human activities—cooking meals and making tools, in addition to building huts—all pointing to simple domesticities six millennia ago.
And while there is a great deal about the early villagers of El Porvenir that remains unknown, we do know this: like humans elsewhere in the past, they built homes.
. . .
So why is there home? Why did the human home evolve?
One prominent hypothesis argues that the human home originates from two biological imperatives: reproductive success and the extended dependency of human offspring.21
Obviously, all species either reproduce or become extinct, but not all species demand the high levels of parental investment in offspring as humans do. The California mussel gives birth to 60,000–70,000 spawn in the crashing waters of the Pacific coast without giving her offspring another thought.
In contrast, human infants cannot walk until nine to twelve months after birth and they do not have all their teeth until sometime after two years old, leading one wag to suggest that instead of a mere nine months of pregnancy, humans have a 32-month gestation period: 9 in utero plus 24 ex utero.
Further, since humans rarely bear more than a single offspring at a time, both parents’ genetic heredity is dependent on one child’s survival to reproductive age (although the more offspring the better the odds). Thus, the argument goes, both parents have a vested genetic interest in the survival of their young.
But the mother’s and father’s investments differ. In traditional societies, mothers typically breastfeed their infants for two to three years or more.22 While the mother-child interactions are sustained and intimate, how does the father contribute? He brings home food, particularly meat. Similarly, male hominids ensured the survival of their offspring by provisioning their families, wandering out to forage (and becoming increasingly bipedal in the process), and returning with food. Rather than risk their parental investment, it is to the reproductive advantage of both parents to have their offspring in a relatively safe location to which resources are transported.
Such are the evolutionary advantages of home.
When this eminently plausible “home-base hypothesis” was first articulated, it seemed to account for a broad range of anthropological facts that relatively quickly became matters of dispute.23 For example, the hypothesis explained the idea of “Man the Hunter” in which males venture out in quest of game, returning with highly prized meat.
But when more detailed ethnographic research was conducted, a different picture emerged. Women in foraging societies often contributed more calories to the diet than men did. Men were not the only hunters, but women, children, and the elderly also hunted small game, fished, or collected shellfish. More surprisingly, detailed studies of meat-sharing indicated that relatively little of a hunter’s catch actually went to his own offspring because of strong social requirements to share meat with other kin or band members.
Finally, critics argued, the classic ethnographies of hunter-and-gatherer societies overlooked the transformations that many of these societies had endured due to contacts with other agrarian or industrial societies and empires. Driven into marginal environments, decimated by introduced diseases, or ensnared through commercial and/or political ties, these ethnographic cases were not frozen representatives of a Lower Paleolithic past.
Ultimately, resolving the questions of the earliest hominid social group was stymied by a simple but daunting fact: it is extremely difficult to find archaeological sites more than one million years old.
First, to find one-million-year-old sites, you have to search one-million-year-old landforms, which are often deeply buried deposits. For example, the Great Rift Valley system of eastern Africa has proven so rich in hominid and other fossils precisely because ancient and deeply buried strata are laid bare in its eroded exposures.
Second, if the artifacts and features created by chimpanzees, bonobos, and gorillas are a guide, the sites created by hominids probably were ephemeral and incompletely preserved. It is unlikely that one-million year-old termite-hunting twigs or improvised leafy nests will ever be discovered by archaeologists.
Finally, even if durable artifacts are found on ancient land surfaces, there is a good chance that such materials will have been moved about by erosion or other natural processes and the archaeological materials are no longer in their original in situ associations.
These challenges only made the sites excavated by Mary Leakey all the more exciting. In meticulous excavations conducted throughout the 1960s, Mary Leakey and her colleagues focused on a number of sites located in the oldest sediments in the main gorge at Olduvai, sediments deposited by a now-dry lake between 1.87 and 1.71 million years old. Leakey excavated in two main areas exposed by streams that cut down through Olduvai’s strata over the last 200,000 years, the DK Locality and the FLK Complex.24
The sites contained a variety of animal bones and stone artifacts: crude choppers, hammer stones, and stone flakes with utilized edges. The faunal remains were surprisingly diverse, including big game (such as ancient relatives of giraffes, elephants, rhinos, zebras, and wildebeests) as well as two species of turtles and one species of tortoise. Twenty-three different taxa of mammals were found, including a large number of crocodile teeth.
In one portion of the DK Locality, Leakey’s team discovered an amazing feature: a circular array of stones. Leakey wrote, “At DK there is a stone circle which is the earliest man-made structure known. It is built of loosely pile blocks of lava and measures three and a half to four metres in diameter. It bears a striking similarity to crude stone circles constructed for temporary shelter by present-day nomadic peoples such as the Turkana in Kenya.”25
Confessing to her own suspicions, Leaky admitted, “The Olduvai structure was a most surprising discovery in view of its age and for a while I was reluctant to believe that the blocks of lava had been artificially arranged into a circle. However, the geologists and prehistorians who have since seen the circle are almost unanimous in considering that it is likely to be the work of the early hominids and not a natural feature.”
Mary Leakey had found the oldest known house on earth.
Other archaeological projects expanded on the Olduvai discoveries, particularly at the FXJj 50 site in northern Kenya, where excavations in the 1970s and early 1980s were directed by Richard Leakey and Glynn Isaac.26 At FXJj 50 a litter of chipped stone tools and animal bones (representing mammals, birds, and fish) suggested the existence of a home base about 1.6–1.5 million years ago. Further, it was possible to fit together the chipped stone flakes and cores at the site—like pieces of a lithic jigsaw puzzle—indicating that the artifacts at FXJj 50 were largely in their original places, undisturbed by time.
Thus,
