Monday, 28 December 2015
Evolution or Revolution?
In a few short centuries, the Yakutian horse has gained a large body and
long, mammoth-like shaggy hair, allowing it to survive truly harsh
conditions
The myth is an attempt to explain why Yakutia has such an abundance of precious diamonds, but it is easy to see why the story developed. This republic of Russia gets very cold indeed. Temperatures can dip to -70 °C (-94 °F) and its capitol, Yakutsk, is the coldest city in the northern hemisphere.
There is life in the freezer though, including a population of stocky, shaggy steeds known as Yakutian horses. The Yakuts would undoubtedly have perished if not for these beasts. Locals relied on the horses for transportation, food in the form of horsemeat, and clothing made from horse hides. Horses have played a central role in the region's economy for hundreds of years.
It turns out that these horses adapted to the extreme Siberian climates with astonishing speed.
Averaging about 150cm, the Yakutian stands a little smaller than most horses. Its winter hair can reach about 10cm in length and it has a thick bushy tail and long mane that, like a shawl, covers both its neck and shoulders.
But how long has it taken the Yakutian horses to adapt to this extreme environment? Are they ancient natives to the region, like the now-extinct mammoths? Or did the Yakuts bring them to the area when they fled Mongolia in the 13th or 14th Century to escape Genghis Khan?
To answer such questions, scientists recently turned to genome sampling.
"We wanted to take horses from today, horses from after the 13th century, and from prior to the 13th century," says Ludovic Orlando of the University of Copenhagen in Denmark, the lead author of the study. "Because that way, we could really track the whole temporal line and see whether or not those population of horses are actually the same through time."
The team sampled the genomes of nine modern day Yakutian horses, one genome from an early 19th Century horse, and another from a horse that lived in the region 5,200 years ago. The scientists then compared the genomes to one another and to existing sequences for dozens of domestic horses, wild Przewalski's horses that are native to the steppes of central Asia, and ancient horses.
"We can exclude the possibility that the Yakutian horses descended from the horses that existed in Yakutia in ancient times," Orlando says.
The team's analyses placed the nine modern-day Yakutian horses and the Yakutian horse from the 19th century within the "evolutionary tree" of domesticated horses. They fall closest to the Mongolian, Fjord and Icelandic horses, with the Mongolian horses their most likely ancestors.
But the Yakutian horses differ significantly in appearance to these Mongol horses. They have adapted to their new environment in just 800 years.
"This is blink-of-an-eye evolution," says Doug Antczak, a veterinarian and equine scientist at Cornell University in Ithaca, New York. "What really captures peoples' imaginations from this research is the evidence for rapid adaption to the environment – in this case a cold, harsh, dry environment."
Icelandic and Fjord horses are also squat and fat with thick hair coats, whereas horses that live in the desert, such as Arabian horses, have shorter and finer hair coats. "There's an infinite gradation between the horses that have fine hair coats and the Yakutian horses," Antczak says.
The geneticists also found genes associated with the metabolism of sugars including glucose, which can have anti-freezing properties in the blood.
In July 2015, a team of scientists compared the genomes of ancient woolly mammoths to those of elephants to determine the features that contributed to the mammoth's appearance and ability to withstand extreme cold. The researchers found similar variations in hair growth, metabolism and stature.
"It shows that there are only so many ways a mammal can get adapted to such environments," Orlando says.
But typically, a mammal would take millennia to reach the level of hardiness that Yakutian horses exhibit today.
"It is amazing that in just 800 years, which is only about a hundred generations for horses, you can get from a regular horse, a type of Mongolian horse, to the Yakutian horses we have today," Orlando says. "It tells you how fast evolution can go."
The myth is an attempt to explain why Yakutia has such an abundance of precious diamonds, but it is easy to see why the story developed. This republic of Russia gets very cold indeed. Temperatures can dip to -70 °C (-94 °F) and its capitol, Yakutsk, is the coldest city in the northern hemisphere.
There is life in the freezer though, including a population of stocky, shaggy steeds known as Yakutian horses. The Yakuts would undoubtedly have perished if not for these beasts. Locals relied on the horses for transportation, food in the form of horsemeat, and clothing made from horse hides. Horses have played a central role in the region's economy for hundreds of years.
It turns out that these horses adapted to the extreme Siberian climates with astonishing speed.
Averaging about 150cm, the Yakutian stands a little smaller than most horses. Its winter hair can reach about 10cm in length and it has a thick bushy tail and long mane that, like a shawl, covers both its neck and shoulders.
We could really track the whole temporal lineIn short, its appearance is a little like the woolly mammoth version of a horse. It is clearly well suited to the brutal and enduring Siberian winters.
But how long has it taken the Yakutian horses to adapt to this extreme environment? Are they ancient natives to the region, like the now-extinct mammoths? Or did the Yakuts bring them to the area when they fled Mongolia in the 13th or 14th Century to escape Genghis Khan?
To answer such questions, scientists recently turned to genome sampling.
"We wanted to take horses from today, horses from after the 13th century, and from prior to the 13th century," says Ludovic Orlando of the University of Copenhagen in Denmark, the lead author of the study. "Because that way, we could really track the whole temporal line and see whether or not those population of horses are actually the same through time."
The team sampled the genomes of nine modern day Yakutian horses, one genome from an early 19th Century horse, and another from a horse that lived in the region 5,200 years ago. The scientists then compared the genomes to one another and to existing sequences for dozens of domestic horses, wild Przewalski's horses that are native to the steppes of central Asia, and ancient horses.
They have adapted to their new environment in just 800 yearsThe findings of the study were unequivocal. In the genomes of the modern Yakutian horses the researchers found a strong signal of a "founder effect": a reduction in genetic variation that results when a small population is used to establish a new colony. The precise level of genetic variation indicates that the small founding population of horses arrived in the Yakutian region about 800 years ago, in the 13th Century.
"We can exclude the possibility that the Yakutian horses descended from the horses that existed in Yakutia in ancient times," Orlando says.
The team's analyses placed the nine modern-day Yakutian horses and the Yakutian horse from the 19th century within the "evolutionary tree" of domesticated horses. They fall closest to the Mongolian, Fjord and Icelandic horses, with the Mongolian horses their most likely ancestors.
But the Yakutian horses differ significantly in appearance to these Mongol horses. They have adapted to their new environment in just 800 years.
"This is blink-of-an-eye evolution," says Doug Antczak, a veterinarian and equine scientist at Cornell University in Ithaca, New York. "What really captures peoples' imaginations from this research is the evidence for rapid adaption to the environment – in this case a cold, harsh, dry environment."
It shows that there are only so many ways a mammal can get adapted to such environmentsFocusing on the variation in the Yakutian horse genome, the team identified the key biological functions involved in the adaptive process: those that modified the morphology, hormones and metabolism of the horses. They found variations in the gene pathways involved in hair development, limb length and body size, explaining the Yakutian horses' unique appearance.
Icelandic and Fjord horses are also squat and fat with thick hair coats, whereas horses that live in the desert, such as Arabian horses, have shorter and finer hair coats. "There's an infinite gradation between the horses that have fine hair coats and the Yakutian horses," Antczak says.
The geneticists also found genes associated with the metabolism of sugars including glucose, which can have anti-freezing properties in the blood.
In July 2015, a team of scientists compared the genomes of ancient woolly mammoths to those of elephants to determine the features that contributed to the mammoth's appearance and ability to withstand extreme cold. The researchers found similar variations in hair growth, metabolism and stature.
"It shows that there are only so many ways a mammal can get adapted to such environments," Orlando says.
But typically, a mammal would take millennia to reach the level of hardiness that Yakutian horses exhibit today.
"It is amazing that in just 800 years, which is only about a hundred generations for horses, you can get from a regular horse, a type of Mongolian horse, to the Yakutian horses we have today," Orlando says. "It tells you how fast evolution can go."
Ice Age ABCs?
Why Are These 32 Symbols Found In Ice Age Caves Across Europe?
7 December, 2015 by Maiya Pina-Dacier
Archaeologist Genevieve von Petzinger has made an incredible discovery.
There’s something about caves that draws you in; as soon as you cross their threshold, you enter a surreal and shadowy alternative world. Back when Europe was deep in the Ice Age something drew people in then too; and they left their marks all over the walls.Archaeologist Genevieve von Petzinger has been studying these marks, which are not only among some of the world’s oldest art, but also some of the most famous. Who can say they have not been impressed by the paintings of Lascaux or Altamira? But, says von Petzinger in a landmark TED talk, we’ve been so caught up by the beautiful, flowing artistry of these painted animals, that we’ve missed something even more remarkable.
Don’t let the animals distract you…
Among the elaborate horses, bulls, bears and hunters, there are some other rather less captivating designs – small geometric motifs, etched onto the walls. Until now, they’ve not received much attention. But as it turns out, these humble designs conceal a much more intriguing mystery.Von Petzinger and her photographer-husband visited 52 caves across Europe recording every instance of these symbols that they could see. They found new, undocumented examples at 75% of the caves they visited, and found the symbols far outnumbered the human and animal images. But the amazing thing was that however many caves they visited, they found the same 32 shapes being used again and again and again.
Ice Age alphabet?
The fact that the same 32 symbols are repeated across sites that span 30,000 years and an entire content is nothing less than mindblowing. But what do they actually mean?The oldest written texts appear well over 5,000 years ago, and these symbols appear some 25,000 years earlier than that, but they don’t quite seem to form a written language – there are neither enough characters to represent all their spoken words, nor do they repeat often enough to be some sort of alphabet.
Nevertheless, they clearly meant something to whoever created them and von Petzinger concludes that whatever that meaning was, these symbols changed the course of human communication; no longer confined to spoken words, or gestural movements, 25,000 years ago human communication finally became graphic too.
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