M.J. Rose

These rather disliked sharks seem to live a ridiculously long time. Scientist are trying to figure out what gives them this incredible longevity.

Using carbon dating and a new method involving proteins in the lens of the eye, Danish scientists have unravelled the mystery of how long Greenland sharks live.
Photograph by WaterFrame / Alamy

From The New Yorker,

The Strange and Gruesome Story of the Greenland Shark, the Longest-Living Vertebrate on Earth
By M. R. O’Connor

“Greenland sharks are among nature’s least elegant inventions. Lumpish, with stunted pectoral fins that they use for ponderously slow swimming in cold and dark Arctic waters, they have blunt snouts and gaping mouths that give them an unfortunate, dull-witted appearance. Many live with worm-like parasites that dangle repulsively from their corneas. They belong, appropriately enough, to the family Squalidae, and appear as willing to gorge on fresh halibut as on rotting polar-bear carcasses. Once widely hunted for their liver oil, today they are considered bycatch. For some fishermen, a biologist recently told me, netting a Greenland shark is about as welcome as stepping in dog poop.

And yet the species has an undeniable magnetism. It is among the world’s largest predatory sharks, growing up to eighteen feet in length, but also among its most elusive. Its life history is a black box, one that researchers have spent decades trying in vain to peer inside. Where do Greenland sharks mate? What is their global range and population structure? And, most enticing of all, how long do they live? A study begun in the nineteen-thirties suggested that the species’ lifespan might well be extraordinary, based on the slow growth rate of a single shark that a scientist was lucky enough to catch twice. Verifying this, however, proved nearly impossible. To determine age in other sharks, biologists count the growth rings on their fin spines and vertebrae. But Greenland sharks have no hard tissues in their bodies; even their vertebrae are soft. The longevity question seemed unanswerable.

The mystery might have lingered were it not for the work of three Danish scientists—a physicist named Jan Heinemeier and two marine biologists, John Fleng Steffensen and Julius Nielsen. Nine years ago, Heinemeier and four of his colleagues published a paper on lens crystallines, a class of proteins found in the human eye. Like all organic molecules, crystallines contain carbon, including trace amounts of the radioactive isotope carbon-14. Unlike other proteins, which undergo constant recycling and replenishment, crystallines remain stable throughout a person’s life; they are envelopes sealed at birth, their contents an artifact from the womb. And, if crystallines are the envelopes, then carbon-14 is the postmark. The isotope has always occurred naturally on Earth, formed wherever incoming cosmic rays strike the atmosphere, but some of the current supply also comes from nuclear-weapons tests. The level fluctuates from year to year, and that means that every given time period has its own carbon-14 signature. (There was a particularly huge spike, called the bomb pulse, in the nuke-happy heyday of the fifties and sixties.) Experimenting on cadavers’ lenses, Heinemeier found that he could measure how much carbon-14 they contained and use it to determine the deceased’s date of birth…”

For the rest, and a video of these sharks, click here.

The tomb is strangely small for a pharaoh. Is there more?

From National Geographic,

Exclusive Photos: Search Resumes for Hidden Chambers In King Tut’s Tomb

Two previous investigations disagreed about what’s behind the tomb walls. Now scientists are launching an all-out effort to solve the mystery.

By Kristin Romey and A. R. Williams

“Luxor, EgyptA third round of ground penetrating radar (GPR) scanning is underway inside the burial chamber of King Tutankhamun, Egypt’s Ministry of Antiquities announced today, as part of an effort to answer a question that has long intrigued and stumped researchers: Are the walls of the famous tomb hiding other chambers—perhaps another royal burial concealed for more than 3,300 years?

Ever since archaeologist Howard Carter discovered the treasure-packed tomb in Luxor’s Valley of the Kings in 1922, experts have believed the space to be strangely small for a pharaoh. Various theories about the tomb have been proposed over the decades, but in 2015 Egyptologist Nicholas Reeves suggested an astounding possibility: The north and west walls might conceal the mummy—and fabulous possessions—of Tut’s stepmother, the legendary beauty Queen Nefertiti.

Two previous scans of the burial chamber, conducted in 2015 and 2016, varied in their results and were determined inconclusive. A third non-invasive GPR scan was commissioned by Egypt’s Minister of Antiquities Khaled El Enany following the recommendation of experts who met in 2016 to study the results of the previous scans. This latest investigation, conducted under the direction of the Polytechnic University of Turin, aims to resolve those results and verify whether or not there are voids behind the walls…”

For the rest, and many photos, click here.

Stay back Mr. Columbus, and scoot over Norse explorers, we have some news…

The migration routes of Polynesian seafarers have become more clear — and all thanks to the sweet potato. (Photo: John Webber/Wikimedia Commons)

From Mother Nature Network,

Polynesian seafarers discovered America long before Europeans, says DNA study
New DNA analysis of sweet potatoes, which were first cultivated in the Americas, is the key.
by Bryan Nelson

“The prevailing theory about the “rediscovery” of the American continents used to be such a simple tale. Most people are familiar with it: In 1492, Christopher Columbus sailed the ocean blue. Then that theory was complicated when, in 1960, archaeologists discovered a site in Canada’s Newfoundland, called L’Anse aux Meadows, which proved that Norse explorers likely beat Columbus to the punch by about 500 years.

Now startling new DNA evidence promises to complicate the story even more. It turns out that it was not Columbus or the Norse — or any Europeans at all — who first rediscovered the Americas. It was actually the Polynesians.

All modern Polynesian peoples can trace their origins back to a sea-migrating Austronesian people who were the first humans to discover and populate most of the Pacific islands, including lands as far-reaching as Hawaii, New Zealand and Easter Island. Despite the Polynesians’ incredible sea-faring ability, however, few theorists have been willing to say that Polynesians could have made it as far east as the Americas. That is, until now.

Clues about the migration patterns of the early Polynesians have been revealed thanks to a new DNA analysis performed on a prolific Polynesian crop: the sweet potato, according to Nature. The origin of the sweet potato in Polynesia has long been a mystery, since the crop was first domesticated in the Andes of South America about 8,000 years ago, and it couldn’t have spread to other parts of the world until contact was made. In other words, if Europeans were indeed the first to make contact with the Americas between 500 and 1,000 years ago, then the sweet potato shouldn’t be found anywhere else in the world until then.

The extensive DNA study looked at genetic samples taken from modern sweet potatoes from around the world and historical specimens kept in herbarium collections. Remarkably, the herbarium specimens included plants collected during Capt. James Cook’s 1769 visits to New Zealand and the Society Islands. The findings confirmed that sweet potatoes in Polynesia were part of a distinct lineage that were already present in the area when European voyagers introduced different lines elsewhere. In other words, sweet potatoes made it out of America before European contact…”

For the rest, click here.