Resurrection of a biblical tree

Date palm pit found at Masada germinates at 2,000 years old

The palm some ancients called the “Tree of Life” has been revived from a 2,000-year sleep, genes and all. In what is now the germination of the oldest known seed, a date pit plucked from ancient rubble at Masada has sprouted, scientists report. The sapling’s genetic fingerprint suggests it is none other than the Judean date palm, a variety referred to in the Bible and long thought extinct.

DATED PALM Archaeobotanist Mordechai Kislev holds ancient date palm seeds (Phoenix dactylifera L.) from Masada (left). The 7.5-month-old sapling (right) grew from one of those seeds. Some early leaves had white patches, perhaps resulting from a lack of chlorophyll. Guy Eisner / Courtesy of Science Magazine

Like the iceman found in the Alps, this Judean date palm opens a window into the past, comments Paul Gepts, a plant geneticist at the University of California, Davis. “A small window, but a window nonetheless.”

Excavations in the ’60s uncovered five date pits in the Dead Sea region of Israel at Masada — a mesa-top Herodian fortress and, in the first century A.D., the last stronghold of Jews who, as the story goes, chose to fall upon their own swords rather than be slaughtered by the Roman forces surrounding them. For decades the seeds sat on a shelf in the office of Mordechai Kislev, an archaeobotanist at Bar-IlanUniversity in Israel.

In 2005, Kislev gave the seeds to botanists who soaked them in hot water and nutrients and planted three in enriched soil. Three months later, the dirt cracked and a single shoot appeared. The researchers nicknamed the tiny sapling “Methuselah” after the oldest person whose age is mentioned in the Old Testament.

The scientists, reporting in the June 12 Science, confirmed the sapling’s age with calibrated radiocarbon dating — a method widely used to date organic remains. Two of the original seeds and seed fragments clinging to the root of the sapling gave calendar dates ranging between 206 B.C. and A.D. 392.

Either way, “it’s in the ballpark of 2,000 years old, which is amazing,” comments Bruce Smith, an archaeobotanist at the Smithsonian Institution in Washington, D.C.

Botanists want to know what a fully grown 2,000-year-old date palm looks like. According to the Bible, Mesopotamian wall paintings and relics from Egyptian tombs, Judean date palms once flourished in the Middle East. But by the time of the crusades, the trees had disappeared, Kislev says. Date trees currently grown on Israeli farms derive from trees originally imported from elsewhere in the Middle East and from California.

Genetic fingerprints from the sapling resemble today’s edible Iraqi (Barhee) and Egyptian (Hayani) varieties more than Moroccan (Medjool) varieties. Still, the gap between the cultivars is wide. Genetic tests including more living date palms and more genes will allow for better resolution of relationships in the future, Kislev says.

Extracting DNA fragments from eroded materials like fossilized grains or T. rex tissue is extremely difficult. In comparison, this living representative of an ancient tree will provide plant geneticists with easy-to-obtain DNA, ripe for testing a number of hypotheses about plant evolution, Smith says.

In a few years, Methuselah may come of age. Only mature female date palms bear fruit. And if the sweet purple dates do blossom, botanists might be able to reintroduce the Judean date palm to the world. It could provide farmers with an edible date palm better suited for harsh, dry climates.

To others, the resurrection of a date pit buried at Masada symbolizes hope, strength and life, Kislev says. “I hope it will be a sweet female,” he says. “Even if it is not so sweet though, I think many people would like to have part of this fruit, or something from this very nice lady.”

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