University of Cuyo Publisher (Argentina) via Salas et al. in Nature
University of Cuyo Publisher (Argentina) via Salas et al. in Nature

Scientists Discover a Rare Genome in an Incan Child Mummy

University of Cuyo Publisher (Argentina) via Salas et al. in Nature
University of Cuyo Publisher (Argentina) via Salas et al. in Nature

The boy was only 7 years old when he died more than 500 years ago, chosen for his beauty and health to be sacrificed in an Incan ritual known as capacochain which children were ritualistically killed to mark an important occasion, prevent a natural disaster, or to exert imperial power and control over the then-expanding Incan empire (1438–1533). In 1985, a group of mountaineers discovered his well-preserved mummy more than 17,000 feet up at the edge of the Aconcagua Mountain in Mendoza, Argentina. It was wrapped in different textiles and surrounded by six statuettes. His hair nearly reached his shoulders, and he wore a necklace.

Now scientists have sequenced the child’s genome, and they’ve discovered that he was part of a rare group of people never before identified genetically. Their findings were published today in the journal Nature.

Antonio Salas, of the Universidade de Santiago de Compostela, and his colleagues sequenced the entire mitochondrial DNA genome extracted from the boy’s lung, then compared it against a worldwide database of approximately 28,000 mitochondrial genomes, which are passed down from mother to child. They say he belonged to a haplogroup called C1bi that has not been identified previously. (A haplogroup is population that shares a common ancestor.)

There are 203 C1b mitogenomes in the genetic record, dating back to the earliest Paleoindian settlements a little more than 18,000 years ago. The boy, however, appears to have been a descendant of a rare genetic sub-clade of maternal ancestors that lived about 14,300 years ago in Peru, the researchers say.

Based on a database of haplotypes, or DNA variations that tend to be inherited together, the authors say that genetic relatives of the boy in the C1bi haplogroup may live in Peru and Bolivia today; they found a few C1bi genetic matches for the child in these locations in the database, including one person who was a member of the Wari Empire (circa 600–1100), in the Peruvian Andes.

But we’d have to look closer for them in today's South Americans. “The fact that C1bi is very uncommon in present-day populations from South America could be explained by insufficient sampling of modern populations,” they write. “Alternatively, this rarity could reflect important changes in the gene pool of South America since the period of the Inca civilization.”

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Drought Reveals Ancient Sites in Scotland That Can Only Be Spotted From the Air
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iStock

Typically rainy Scotland is in the middle of an unusually dry summer—and local archaeologists are taking advantage of it. As the BBC reports, the drought has revealed ancient sites, including Roman camps and Iron Age graves, that have been hidden by farm soil for years.

Historic Environment Scotland has been conducting aerial surveys of the country's landscape since the 1930s, but it's in seasons like this, when the crops recede during dry weather, that the buried remains of ancient structures are easiest to spot. Conditions this summer have been the best since 1976 for documenting archaeological sites from the sky.

Aerial view of field.
Historic Environment Scotland

The crescent-shaped crop mark in the photo above indicates a souterrain, or underground passageway, that was built in the Scottish Borders during the Iron Age. The surveyors also found remains of a Roman temporary camp, marked by straight lines in the landscape, built in modern-day Lyne—an area south of Edinburgh already known to have housed a complex of Roman camps and forts.

Aerial view of field.
Historic Environment Scotland

In the image below you'll see four small ditches—three circles and one square—that were likely used as burial sites during the Iron Age. When crops are planted over an ancient ditch, they have more water and nutrients to feed on, which helps them grow taller and greener. Such crops are especially visible during a drought when the surrounding vegetation is sparse and brown.

Aerial view of field.
Historic Environment Scotland

Historic Environment Scotland has a team of aerial surveyors trained to spot the clues: To date, they've discovered more than 9000 archaeological sites from the air. HSE plans to continue scoping out new areas of interest as long as the dry spell lasts.

It's not just in Scotland that long-hidden settlements are coming to light: similar aerial surveys in Wales are finding them too.

[h/t BBC]

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Billion-Year-Old Rocks Reveal the First Color Ever Produced by a Living Thing
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iStock

Billions of years ago, before there were plants and animals on Earth, there were rocks, tiny organisms, water, and not much else. It’s hard to envision what our barren planet looked like back then, but scientists now have some idea of what colors dominated the landscape.

As Vice reports, a team of researchers from Australian National University (ANU) were able to pinpoint the oldest colors ever produced by a living creature: purple-red hues dating back more than 1.1 billion years. The pigments, which appear pink when diluted, were found in molecular fossils of chlorophyll that had been preserved in rocks beneath the Sahara desert. A billion years ago, though, this area was “an ancient ocean that has long since vanished,” Nur Gueneli of ANU said in a statement.

Chlorophyll may very well be green, but these pinkish pigments are a result of "fossilized porphyrins, a type of organic compound that forms an atomic ring around a magnesium ion to form a chlorophyll molecule," Vice explains.

While this provides an interesting visual, the color itself is less important than what it reveals about some of the earliest life forms on Earth. Scientists determined that the chlorophyll was produced by ancient organisms called cyanobacteria, which derived energy via photosynthesis and ruled the oceans at that time, researchers wrote in a paper published in the Proceedings of the National Academy of Sciences. Larger planktonic algae—a potential food source for bigger life forms— were scarce, which may explain why large organisms didn’t roam the Earth a billion years ago. That kind of algae was about a thousand times larger than the cyanobacteria.

“The cyanobacterial oceans started to vanish about 650 million years ago, when algae began to rapidly spread to provide the burst of energy needed for the evolution of complex ecosystems, where large animals, including humans, could thrive on Earth," ANU associate professor Jochen Brocks said.

So the next time you encounter algae, you can thank it for helping you secure a spot on this planet.

[h/t Vice]

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