Oldest human remains from Puerto Rico contradict idea of simple island nomads | Science

Over 2 days in 2019, William Pestle drove a truck containing 35 carefully packed boxes from Virginia to Florida. At night, the University of Miami bioarchaeologist brought the boxes inside his hotel room for safekeeping. This was no ordinary cargo: Inside were the oldest human remains yet found in Puerto Rico.

A new analysis of the bones—some dating back about 3800 years—sheds light on the lives and rituals of Puerto Rico’s early inhabitants. Although typically thought of as roaming, nomadic fishers, the study, published today in PLOS ONE, suggests these people buried multiple generations of their dead in a single place and ate a more varied diet than previously believed.

It’s commendable work, says Reniel Rodríguez Ramos, an archaeologist at the University of Puerto Rico at Utuado who was not involved with the study. The age of the remains, combined with the island’s harsh climate, can make such analyses challenging. “With what they had, they definitely did wonders.”

Puerto Rico’s first inhabitants are believed to have come from South and Central America into the Antilles archipelago around 2500 B.C.E. But very little is known about these earliest Caribbean settlers. The island’s hot, humid conditions mean human and animal bones deteriorate relatively quickly. Only a handful of sites, and fewer than 20 human burials, have been found from this period. Based on the limited archaeological record, researchers generally thought these early settlers lived nomadic lives, constantly moving around the island without establishing complex social systems or building permanent settlements.

But the newly studied remains put those beliefs to the test. In 1993, an archaeological excavation was carried out on behalf of a construction company in an area in southwestern Puerto Rico known today as Cabo Rojo. The dig yielded the remains of five individuals, along with food remains and artifacts such as stone tools and pendants. When the construction company went out of business, however, the excavated remains stayed sealed up in boxes. At first, they were kept in Puerto Rico. Later, they were kept in Virginia by Daniel Koski-Karell, a private contractor who directed the excavation.

Three decades later, Koski-Karell teamed up with Pestle, whom he knew through a mutual friend. With support from the Puerto Rican government and the Institute of Puerto Rican Culture, the duo set out see what  could be learned from the remains.

Radiocarbon dating revealed the five individuals lived between approximately 1900 B.C.E. and 800 B.C.E. The earliest remains represent the oldest human remains yet found in Puerto Rico. Pestle’s group also studied the composition of carbon and nitrogen isotopes in the bones, which can provide clues to the diets of the individuals, such as whether they ate more seafood or terrestrial food, and what types of plants they consumed. They found the islanders regularly dined on both seafood and land-based animals; they also ate a lot of plants high in carbon-4—such as maize—suggesting they may have been experimenting with plant domestication. Compared with people analyzed from other ancient Puerto Rican burial sites, the Cabo Rojo individuals appear to have enjoyed a particularly diverse diet.

“They weren’t ordering from the same menu all the time as everybody else,” Pestle says.

The five burials span a period between 500 and 1000 years, suggesting some people may have settled permanently at the Cabo Rojo site, despite their nomadic reputation. “This place meant something to them,” Pestle says. Perhaps by burying their ancestors here, he adds, they were making a sort of territorial claim. Similar burials stretching over decades and even centuries have been found in early sites in Cuba, which may force researchers to rethink whether early inhabitants across the Caribbean were nomadic.

Combined with previous studies suggesting these early Puerto Rican inhabitants may have domesticated plants and built ceramics, the findings begin to tell of a more complex society than was previously thought. It “vindicates the history of populations that did not have the chance of telling [their] own story,” says Yadira Chinique de Armas, a bioarchaeologist at the University of Winnipeg. She hopes the next step will be finding and sequencing the remains’ ancient DNA, which will illuminate their ancestral connections.

Under the terms set by the Puerto Rican government, once researchers have finished analyzing the remains, they will be returned to the island—“where they shouldn’t have left in the first place,” Pestle says.

Rodríguez Ramos hopes the new results push researchers to continue to look for the remains of other early inhabitants in Puerto Rico. He is tantalized by the possibility of discovering remains at even older sites, such as Puerto Ferro in Vieques, a small island that is part of Puerto Rico, which has been dated to about 1900 B.C.E. “They are our most ancient ancestors who lived here the longest time and, unfortunately, one of the least that we know of.”

Over 2 days in 2019, William Pestle drove a truck containing 35 carefully packed boxes from Virginia to Florida. At night, the University of Miami bioarchaeologist brought the boxes inside his hotel room for safekeeping. This was no ordinary cargo: Inside were the oldest human remains yet found in Puerto Rico.

A new analysis of the bones—some dating back about 3800 years—sheds light on the lives and rituals of Puerto Rico’s early inhabitants. Although typically thought of as roaming, nomadic fishers, the study, published today in PLOS ONE, suggests these people buried multiple generations of their dead in a single place and ate a more varied diet than previously believed.

It’s commendable work, says Reniel Rodríguez Ramos, an archaeologist at the University of Puerto Rico at Utuado who was not involved with the study. The age of the remains, combined with the island’s harsh climate, can make such analyses challenging. “With what they had, they definitely did wonders.”

Puerto Rico’s first inhabitants are believed to have come from South and Central America into the Antilles archipelago around 2500 B.C.E. But very little is known about these earliest Caribbean settlers. The island’s hot, humid conditions mean human and animal bones deteriorate relatively quickly. Only a handful of sites, and fewer than 20 human burials, have been found from this period. Based on the limited archaeological record, researchers generally thought these early settlers lived nomadic lives, constantly moving around the island without establishing complex social systems or building permanent settlements.

But the newly studied remains put those beliefs to the test. In 1993, an archaeological excavation was carried out on behalf of a construction company in an area in southwestern Puerto Rico known today as Cabo Rojo. The dig yielded the remains of five individuals, along with food remains and artifacts such as stone tools and pendants. When the construction company went out of business, however, the excavated remains stayed sealed up in boxes. At first, they were kept in Puerto Rico. Later, they were kept in Virginia by Daniel Koski-Karell, a private contractor who directed the excavation.

Three decades later, Koski-Karell teamed up with Pestle, whom he knew through a mutual friend. With support from the Puerto Rican government and the Institute of Puerto Rican Culture, the duo set out see what  could be learned from the remains.

Radiocarbon dating revealed the five individuals lived between approximately 1900 B.C.E. and 800 B.C.E. The earliest remains represent the oldest human remains yet found in Puerto Rico. Pestle’s group also studied the composition of carbon and nitrogen isotopes in the bones, which can provide clues to the diets of the individuals, such as whether they ate more seafood or terrestrial food, and what types of plants they consumed. They found the islanders regularly dined on both seafood and land-based animals; they also ate a lot of plants high in carbon-4—such as maize—suggesting they may have been experimenting with plant domestication. Compared with people analyzed from other ancient Puerto Rican burial sites, the Cabo Rojo individuals appear to have enjoyed a particularly diverse diet.

“They weren’t ordering from the same menu all the time as everybody else,” Pestle says.

The five burials span a period between 500 and 1000 years, suggesting some people may have settled permanently at the Cabo Rojo site, despite their nomadic reputation. “This place meant something to them,” Pestle says. Perhaps by burying their ancestors here, he adds, they were making a sort of territorial claim. Similar burials stretching over decades and even centuries have been found in early sites in Cuba, which may force researchers to rethink whether early inhabitants across the Caribbean were nomadic.

Combined with previous studies suggesting these early Puerto Rican inhabitants may have domesticated plants and built ceramics, the findings begin to tell of a more complex society than was previously thought. It “vindicates the history of populations that did not have the chance of telling [their] own story,” says Yadira Chinique de Armas, a bioarchaeologist at the University of Winnipeg. She hopes the next step will be finding and sequencing the remains’ ancient DNA, which will illuminate their ancestral connections.

Under the terms set by the Puerto Rican government, once researchers have finished analyzing the remains, they will be returned to the island—“where they shouldn’t have left in the first place,” Pestle says.

Rodríguez Ramos hopes the new results push researchers to continue to look for the remains of other early inhabitants in Puerto Rico. He is tantalized by the possibility of discovering remains at even older sites, such as Puerto Ferro in Vieques, a small island that is part of Puerto Rico, which has been dated to about 1900 B.C.E. “They are our most ancient ancestors who lived here the longest time and, unfortunately, one of the least that we know of.”