I was very wrong.
We began excavating the mounds of El Porvenir. We laid out 2 × 2 meter test pits arranged in a row to transect the mound, their edges lined by taut staked strings. We scraped through the hard dun clay, and within inches of the surface encountered the first traces of ancient dwellings.
There was not much to see. A few irregular lumps of adobe bricks, fire-reddened and ashy—the remains of a cooking hearth. A harder surface was a floor compacted by footsteps. A right-angled line of postholes penetrated the floor, small divots darkened by the rotted wooden poles that once supported the walls. A cluster of sun-dried clay chunks bore grooved imprints of river canes. From such prosaic traces, we discovered a portion of a roughly rectangular structure built from wattle and daub, and the cooking hearth indicated that we had uncovered an ancient home.
Below this floor was a jumbled stratum of fill, a craze of rubble and shells. The shells were principally of oysters and other mollusks that lived in mangrove swamps now located 6–10 kilometers west of El Porvenir. The clutter of shells, cocked at every angle, was a garbage dump, or midden, rather than the floor of a prehistoric home.
Under the midden layer were the fragments of another earlier house. Later occupants of El Porvenir had dug into and destroyed the lower levels, yet enough remained of the earlier structure to partially reconstruct it. In one corner there was a basin-shaped hearth molded from mud and holding grey ash and charcoal flecks. We found sections of compact floor made from intentionally poured layers of grayish river mud; the grey mud floor was ripped away in places by later trenching, but clearly defined an earlier dwelling. More post-molds were visible in the preserved patches of flooring, arching in a broad curve that indicated an elliptical structure. There were no traces of mud daub, indicating that this earlier house differed in plan and construction from the rectangular wattle and daub house perched above it.
We troweled into even earlier layers. As each stratum was uncovered, all the features were mapped and photographed. The soil was screened to recover the smallest fragments of the past.
We dug through another thick stratum of oyster, removing over 500 kilograms of bone-grey shells. In the same layers we found hundreds of fragile fish bones from catfish, mullet, tuna, sea bass, and other delectable fish. Some species had been netted and hooked in the quiet mangrove estuaries, others taken from boats on the open sea. Small pottery shards and stone flakes sprinkled the shell midden as we dug down in the mound.
And finally we came upon the very oldest house at El Porvenir.
The traces of the house were simply a curved wall marked by small post-molds. The posts had been set in pairs, presumably on both sides of an elliptical wall. Additional posts were set in the middle of the floor, apparently supporting narrow roof-beams that intersected like the spokes of a wheel. We estimated that the structure would have been about five meters in diameter. The floor consisted of a compact layer of dense midden.
When we excavated this floor we thought it was old, but only six months later—after we were able to export samples for radiocarbon dating and obtained the laboratory results—did we know just how old. The samples from the oyster shell layer dated to 4700–4340 B.C. and the floor was older than that—the house was more than 6,000 years old. The prehistoric house at El Porvenir is one 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