Free Tasty by John McQuaid Page B

this makes it possible to use differences in the DNA of related species to extrapolate how long ago they diverged from a common ancestor, or when a particular mutation happened. Wooding compared the human DNA code for Fox’s bitter-taster gene in a human to that of a chimp. What he saw surprised him: the genes looked nothing alike. Somehow, different DNA codes produced identical taste experiences. Chimps and humans had each evolved the same traits independently, a finding that hinted they were even more potent survival tools than anyone thought.
    Scientists have tracked these genetic signals through the past several million years and around the world, looking for what shaped them. Tasting and non-tasting had emerged first in chimpanzees, more than 5 million years ago, and more recently in early humans, between 1.5 million and 500,000 years ago—around the time that older species were starting to give way to the early Homo sapiens . Neanderthals, whose species split from a common ancestor with humans about 400,000 years ago, included both tasters and non-tasters, too. Carles Lalueza-Fox of the Evolutionary Biology Institute in Barcelona tested DNA from a 48,000-year-old fossil of a male Neanderthal unearthed, along with ten others, from a cave in El Sidrón, Spain. The Neanderthal turned out to be a taster.
    â€¢Â â€¢Â â€¢
    When modern humans departed Africa around one hundred thousand years ago on their way to populating the world, they carried these genetic variations with them. Taste’s small supporting role in this journey still echoes today in the taste for coffee and in produce choices in the supermarket, and shapes flavors throughout the world.
    The crossing out of Africa likely occurred at what’s now called the Bab el-Mandeb Strait near the southern outlet of the Red Sea, the narrowest stretch of water separatingNorth Africa from the Arabian Peninsula. Today, the strait is nearly twenty miles wide. But long ago, the Indian Ocean was hundreds of feet lower, and the strait was narrow and shallow, easy to cross by makeshift raft or maybe even by wading. Humans and their immediate ancestors were expert travelers. Similar crossings had occurred before, many times. Some early humans, like the people who tamed fire at the Gesher Benot Ya’aqov cave 700,000 years earlier, had made it as far as what is now Israel, about 1,400 miles to the north. Homo erectus had trekked to East Asia. And, as the humans camped on the beach, Neanderthals were hunting in Europe’s forests.
    These humans were more perceptive than their predecessors. Hundreds of thousands of years of evolution had made their brains larger, and their tastes simultaneously more robust and refined. The world had become one big lab for testing new tools and techniques for the hunt and the hearth. More than a hundred thousand years before the Bab el-Mandeb crossing, early humans started making earth ovens, digging deep pits and lining them with flat stones to focus heat for roasting game, roots, and vegetables. They may have smoked meat to preserve it, infusing it with new flavors in the process. They shared archaic recipes and passed them down the generations, tinkering as they went. These practiced rituals were a hedge against starvation wherever they traveled.
    No one knows what drove them out of Africa for the unknown—possibly a famine, or some tribal dispute. Whatever it was, genetic evidence suggests that a small group of hundreds, or at most thousands, of people passed through this or several similar gathering points nearby, in a single exodus. Their descendants spread through therest of the world, displacing (and sometimes interbreeding with) the only other human species around, Neanderthals. Virtually all non-­African people in the world today are descended from the relatively small group that crossed at Bab el-Mandeb.
    By chance, this founder group had quirky tastes. Genetic detective work indicates that in the