Finely tuned nervous systems allowed birds and mammals to adopt smoother strides
January 27, 2020
Since the 1900s, neuroscientists have known that the peripheral nervous systems of tetrapods (four-footed animals) vary greatly, but how these differences affect the way that animals walk, run, or move has not been well understood. Now, a study published in the Journal of Experimental Biology on January 27, authored by a New York Institute of Technology anatomy professor, suggests that neuromuscular adaptations in mammals and birds may have allowed them to become more nimble than reptiles and amphibians.
“This research could explain why tigers have a much smoother walk than crocodiles, which lumber and drag their abdomens, and perhaps one reason why today’s humans have evolved to walk with such uniform steps,” says lead author Michael Granatosky, Ph.D., assistant professor of Anatomy at New York Institute of Technology College of Osteopathic Medicine (NYITCOM).
Tetrapods have small receptors in their muscles called Golgi tendon organs, which protect muscles from forces during locomotion (walking) and other physical activity. When muscle tension becomes dangerous, these receptors signal the nervous system to produce reflexes that release tension and prevent injury. Amphibians and reptiles, which diverged from early tetrapods before mammals and birds, have freeform Golgi tendons located further from the muscle-tendon junction, suggesting that they detect stress across the entire muscle. In contrast, birds and mammals have encapsulated Golgi tendon organs set directly at the muscle-tendon junction, signifying an ability to detect tension in precise muscle areas, which would allow for more controlled motion. Now, researchers pose that birds and mammals owe their agile strides to these finely tuned receptors.
“These structural variations are well known, but no one has questioned what they actually mean for the animals,” says Granatosky. “We studied the largest collection of zoological locomotive data to date, which spanned 30 years and 55 species, and found that these variations directly affect how animals respond to the forces acting on their limbs.”
Continuing the work of his post-doctorate mentor Callum Ross, Ph.D., professor of Organismal Biology and Anatomy at the University of Chicago, Granatosky analyzed vast sets of data from zoos and research facilities in the U.S., Canada, and Germany. To survey bodyweight distribution in motion, animal steps were measured with a three-dimensional scale called a force plate. Reptile and amphibian strides were found to vary greatly with each step, but mammals and birds crossed the force plate with very consistent strides. The findings suggest that, while in motion, a predictable response to force provides a selective advantage that could conserve energy and allow birds and mammals to swiftly regain footing from a fall. Granatosky also believes that the less responsive nervous systems of reptiles and amphibians may have caused a need for protection that led the animals to adapt stronger bones.
“Reptile and amphibian bones can sustain forces ten times heavier than their weight, whereas bird and mammal bones can only sustain forces two and a half times their weight. It’s possible that birds and mammals adapted lighter, more energy-efficient bone structures in response to no longer needing heavy, protective frames that demanded a great deal of energy,” he says.
To test his theory, Granatosky will study whether Golgi tendon organs played an evolutionary role in bone density adaptation and energy expenditure. He is also collaborating with New York Institute of Technology engineering, architecture, and digital arts students to build robots that accurately simulate animal locomotion. The first robot will simulate the walking patterns of the blue-tongued skink, an Australian lizard commonly used as a model for early tetrapod locomotion.
The British Prince Andrew is not cooperating with a US authorities investigation into sex offender and multi-millionaire Jeffrey Epstein. Geoffrey Berman, the prosecutor in New York, said that in a press conference in front of Epstein‘s house.
The US prosecutor and the federal police service FBI want to hear the prince about his relationship with multi-millionaire Epstein, who died … in his cell last year after his large-scale abuse of minors came to light. But Andrew did not respond to the request.
Five women who claim to have been abused by Epstein already asked Prince Andrew to cooperate in December. Attempts to talk to the prince failed, so the women’s lawyer wants to sue him.
PRINCE ANDREW ‘UNCOOPERATIVE’ IN EPSTEIN PROBE Britain’s Prince Andrew has not responded to interview requests by the FBI regarding his relationship with Jeffrey Epstein. “The Southern District of New York and the FBI have contacted Prince Andrew’s attorneys and requested to interview Prince Andrew and to date Prince Andrew has provided zero cooperation,” U.S. Attorney Geoffrey S. Berman said. [HuffPost]
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What makes Rembrandt’s paintings technically so extraordinary, and why are different people so deeply affected by his oeuvre, or a specific work? Centuries after his death, his paintings are still a source of drama and gripping plot twists.
Rembrandt’s paintings have lost none of their appeal in the 350 years since his death. Collectors worldwide cherish the magic of the Dutch master’s work.
This entertaining documentary shows the passion of a variety of Rembrandt enthusiasts. An eccentric, aristocratic Scot is looking for the ultimate place to hang his beloved portrait of a woman reading, and an animated Amsterdam art dealer has his eye out for a second chance to discover a “new” Rembrandt—this descendant of an old merchant family, whose ancestor was once painted by Rembrandt himself, has got something to prove.
An ambitious American businessman and his wife proudly make “their” Rembrandts available to the Louvre, and the Rothschild family’s decision to put Rembrandt’s wedding portraits of Marten Soolmans and Oopjen Coppit on the market threatens to provoke a diplomatic row between the Netherlands and France.
These issues have at least two sides. On the one hand, about Rembrandt himself and money and social classes. On the other hand, about Rembrandt’s works, money and social classes in our 21st century. It turns out that lots of money in art may destroy friendships between people and governments.
Rembrandt was luckier financially than Vincent van Gogh and many other artists. Van Gogh sold just one painting for little money while he was alive. However, after his death, Van Gogh, in a cruel twist of economical mechanisms, like quite some others, became an artist off whom some people made very much money. Rembrandt sold many paintings, usually for good money. But, as he spent much on eg, attributes for his paintings, he went bankrupt and died relatively poor. After his death, like with many other artists, some people who had never contributed a drop of paint to his art got very rich off it.
As for Rembrandt and social class: like Rubens, Rembrandt lived in the time of the Low Countries’ revolt against the kings of Spain. The Spanish monarchs managed to defeat that uprising in the south, in what, roughly, is now Belgium. However, the north became the independent Dutch republic. Rembrandt lived in the bourgeois Dutch republic. Rubens in the Spanish Netherlands, ruled by princes and nobles. The differences in social context between Rembrandt and Rubens meant differences in the subjects of their art.
In the Dutch Republic, there was no monarchical court comparable to most 17th century European countries.
Which would have liked very much to be a princely court like elsewhere in Europe; but constitutionally wasn’t.
Rembrandt got a commission from that princely court (princely, as the Stadhouders were also absolute monarchs in the tiny statelet of Orange in southern France).
A Hermitage Amsterdam exhibition noted that Stadhouder Frederik Hendrik prefered painters from the feudal southern Netherlands, though that region was the military enemy, to “bourgeois” northern painters like Rembrandt. He also prefered Gerard van Honthorst to Rembrandt as a painter of portraits of his wife. Honthorst was not from the Spanish occupied southern Netherlands. However, his home province Utrecht in the central Netherlands was less bourgeois rebellious than Rembrandt’s Holland. And Honthorst had spent much time in feudal Italy.
So, Rembrandt got most of his commissions for painting not from the Stadhouder’s court, but from bourgeois merchants, especially in Amsterdam city: the ruling class of the newly independent republic. They were as rich, or often richer, as nobles in other countries. Usually, they did not live in castles in the countryside, but in houses along canals like the Amsterdam Herengracht.
In one of the first scenes, the Rijksmuseum says they would like very much to have a painting which is now not in any of the houses to which Rembrandt sold his work, but in a big feudal castle in Scotland.
This Rembrandt work, Old woman reading, is owned by the Duke of Buccleuch. If for some reason, the castle owners would no longer want it, then the Rijksmuseum would like very much to bring it back to the city where it was painted.
A Rembrandt painting which is already in Amsterdam is this portrait of the merchant and mayor Jan Six.
The Six family still owns it. In the 19th century, this originally bourgeois dynasty got the title of nobility jonkheer (baronet).
Another family who got a title of nobility then was the Rothschild family, originally bankers. In the first part of the film, Baron Éric de Rothschild was still the owner of the Rembrandt’s wedding portraits of Marten Soolmans and Oopjen Coppit.
However, it seems that the Rothschild family is not as rich and powerful as some conspiracy theorists think, not as good in tax dodging as some other rich persons: Baron Éric de Rothschild’s brother owed debts to tax authorities. To pay these, Éric de Rothschild needed 160 million euros. The proceeds of selling his beloved portraits of Marten Soolmans and Oopjen Coppit, hanging at both sides of his bed in Paris.
Éric de Rothschild does not like interviews, and the filmmaker had just one hour for talking to him. Previously, an appointment for an interview had turned out to be impossible because of a Yellow Vest demonstration in Paris.
Ms Hoogendijk also made Marten & Oopjen, a TV film about the wedding portraits of Marten Soolmans and Oopjen Coppit.
So, these portraits cost 160 million euros. The Paris Louvre museum did not have that money. Neither had the Rijksmuseum in Amsterdam. But the Rijksmuseum collected money and was almost at 160 million. Then, the French government banned these two paintings from going from private property in France to public property in the Netherlands. A diplomatic conflict between the European Union member governments of France and the Netherlands was imminent. It turned out to be not as sharp a conflict as the proxy oil war between the European Union member governments of France and Italy in Libya. The Dutch government, being smaller than the French one, gave in. There was a compromise: both museums paid 80 million euros, mostly government money. And the two paintings would sometimes be together in the Louvre, sometimes together in the Rijksmuseum.
A major role in this documentary is Jan Six. Not the 17th-century Jan Six depicted by Rembrandt, but a 21st-century relative. An art historian and art dealer, that Jan Six, ‘Jan Six XI‘, used to work at Sotheby’s. He claims to have discovered two unknown works by Rembrandt. No Rembrandt painting had been rediscovered for 42 years.
Some unknown 17th century painter had painted over the Rembrandt original, so recognizing the work as a Rembrandt was not obvious. It is probably from when Rembrandt was still young and lived in Leiden.
This is the other newly discovered Rembrandt: Portrait of a Young Gentleman.
The discovery showed how money in art can ruin friendships. Jan Six had bought the painting for 160,000 euros on behalf of an anonymous investor from an owner who did not suspect it was a Rembrandt. Fellow art dealer Sander Bijl claimed that Six had broken an agreement to buy the painting together. The purchase also caused a conflict between Six and Rembrandt expert Ernst van de Wetering.
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