The body of a canid puppy preserved for 14,000 years in the Siberian permafrost has helped scientists make a crucial breakthrough in archaeological RNA analysis. In the right conditions, DNA can be extracted from archaeological remains thousands of years old, but the widely accepted hypothesis was that RNA degrades relatively quickly due to enzymatic action in plants and animals, especially in mammalian soft tissues.  Recent studies have been able to reveal RNA genomes in archaeological material, almost all of the specimens from plant seed endosperm which is uniquely suited to long-term preservation. A new study sought to sequence RNA in historic and archaeological tissue specimens that, through rapid desiccation or freezing, had been exceptionally well-preserved.

The team took five samples from three canids: one sample each from two historical wolves (19th and 20th century) from Greenland, and tissue from the liver, cartilage and muscle of a “wolf” puppy discovered in Tumat, Siberia, in 2015. The pup was found in the thawing permafrost and many of its soft tissues had survived the 14,000 years in excellent condition. It was identified as a juvenile canid, but it’s not clear whether it was a wolf pup or a domesticated wolf-dog hybrid.

The DNA of the samples had already been sequenced, which gave researchers the means to verify the authenticity of any RNA results. Not surprisingly, there was much more RNA in the two historical samples, but the team was able to sequence the RNA from the Tumat canid’s liver tissue. This is the oldest directly sequenced RNA by at least 13,000 years.

“Ancient DNA researchers have previously been reluctant to attempt to sequence ancient RNA because it is generally more unstable than DNA, and more prone to enzymatic degradation,” [University of Copenhagen’s Dr. Oliver] Smith said.

“However, following our recent successes in sequencing ancient RNA from plant material, we speculated that a well-preserved animal specimen, frozen in the permafrost, just might retain enough material to sequence.”

“To our delight, we found that not only did we find RNA from various tissues, but in some case the signal was so strong that we could distinguish between tissues in a way that makes biological sense.”

“Knowing that RNA acts as an intermediary between DNA and proteins, both of which are more stable, it might be tempting to ask, ‘so what?’ But we think the future of ancient RNA has great potential. For example, many of the most clinically relevant viruses around today have RNA genomes, and the RNA stage is often crucial to understanding the intricacies and complexities of gene regulation. This might have repercussions when discussing the environmental stresses and strains that drive evolution.”

The results of the study have been published in the open access journal PLoS Biology.

Archaeologists have discovered a rare Pictish symbol stone that was reused as a headstone in the 18th century. It was found during a survey of an early Christian church site near Dingwall in the Scottish Highlands. It had been identified as a likely cross slab dating to the late 8th century. An inscription squeezed in on the top left of the front face reads: “Hugh McAulay Alexander McAulay January 2 1796.”

Cross slabs are named for a design element — an intricately carved cross — found on at least one side. There are around 350 recorded and documented Pictish symbol stones. There are only around 50 carved Pictish cross slabs known. There is no cross on the front of the newly discovered stone (which technically makes it the back, or reverse of the stone; the cross side is the obverse). When the back of the slab is cleaned and if the carvings are sufficiently extant, experts will be able to confirm whether this is a cross slab.

Only about half of the height of the stone survives. Archaeologists think it was originally over six feet tall; there’s just over a meter (3.2 feet) left, likely from the top part. There are carvings on both sides — archaeologists saw as much when the stone was lifted, but the coating of soil obscured the imagery.

John Borland, of Historic Environment Scotland and president of the Pictish Arts Society, said: “The discovery of the top half of a large cross slab with Pictish symbols is of national importance.

“The find spot – an early Christian site in Easter Ross – is a new location for such sculpture so adds significant information to our knowledge of the Pictish church and its distribution,

“This new discovery will continue to stimulate debate and new research.”

Recycled Pictish stones have been found before. They were reused as boundary stones and lintels, in portals and as headstones. This one has some characteristic Pictish abstract designs including the Z-rod and Double Disc, but it has Celtic interlace motifs as well. This is typical of later symbol stones which syncretized the decorative traditions and included carved pictorial references to Biblical characters, see the Nigg Church Pictish cross-slab, for example.

The stone was raised on Thursday and will be cleaned and conserved. Eventually it will be exhibited in a museum, ideally in the Highlands.

The 3,800-year-old relief with the emoticon-like seed discovered last year at the ancient site of Vichama in Peru has a new-found friend: a toad with anthropomorphic hands on each side of a disembodied head. This tableau is on a small wall in front of the larger frieze, but they share a common theme. The large frieze on the nine-foot wall behind this ones featured four disembodied human heads with two serpents winding above them that meet over the anthropomorphic seed putting down roots and looking really happy about it. 

Snakes and toads both represented water in the Norte Chico civilization which occupied Vichama about 1800 B.C., a period afflicted by a succession of droughts that ultimately lead to the abandonment of Caral, Norte Chico culture’s captial and its largest and oldest city. Vichama, thanks to its proximity to the ocean and the freshwater Huara River, outlasted it by centuries.  The city was abandoned around 1500 B.C.

Dr Ruth Shady Solís, director of the Caral Archaeological Zone (ZAC), believes the scene represents the “arrival of water” through rainfall.

She says that in Andean civilisation, toads represented water and says the face below it represents humans waiting for rainfall to give continuity of life. […]

Researchers said the sculptures would probably have been produced in a period of scarcity and famine.

Tatiana Abad, another archaeologist at the site, said at a news conference on Monday the carving represented a time of “crisis” for the people living there.

There are some differences between the figures on the background and foreground relief. The toad on the newly-discovered wall has PacMan-like pupils that look due east. The human face has the east side eye open and the west side one closed. (The heads on the long frieze all have closed eyes.) That persistent unidirectional strabismus may be a reference to the Andes which like to the east of Vichama and are the source of fresh water for the coast.

The friezes were found in the anteroom of a large ceremonial hall that was almost 10,000 square feet in total area. That structure overlooked the agricultural fields of the Huaura River valley. The building was used for centuries and was constantly being remodeled, repaired and redesigned. Several important sculptural friezes have been found since excavations began in 2007. The motif of famine is addressed in many of them even more directly, depicting anthropomorphic characters with empty stomachs, some dead, other engaged in a ritual dance. Archaeologists have also discovered 22 architectural complexes including public buildings, plazas — one circular sunken one — and residential dwellings.