Genes •

Horse Domestication History Revealed By Ancient DNA

December 16, 2014 By Rebecca McGhee Leave a Comment

Speed, smarts, and the heart of a champion: utilizing genomic investigation, researchers have recognized DNA changes that helped transform aged horses, for example, those in ancient cavern art into today’s Secretariats and Black Beauty, specialists reported Monday.

Understanding the hereditary changes implicated in equine domestication, which prior studies followed to the windswept steppes of Eurasia 5,500 years back, has long been high on the list of things to get of evolutionary geneticists as of the vital part that taming wild horses played in the advancement of society.

When traders, officers and voyagers could jog instead of simply walk, it transformed trade, combat, the movement of individuals and the transmission of thoughts. It likewise empowered the advancement of continent sized domains like the Scythians 2,500 years back in what is presently Iran.

“It was all made possible by 125 genes,” as indicated by the findings of the study published in Proceedings of the National Academy of Sciences.

Identified with skeletal muscles, parity, coordination, and heart quality, they delivered traits so alluring that old raisers chose horses for them, said geneticist Ludovic Orlando of the Natural History Museum of Denmark, who conducted the study. The result was based on eras of horses personalized for chariotry, pulling plows, and racing.

Genes active in the cerebrum likewise experienced assortment. Variations connected to social conduct, learning, terror reaction, and friendliness are all more profuse in domesticated horses.

The disclosure of the hereditary premise for horse domestication was bound to happen as no wild relatives of antiquated breeds survive. The closest is the Przewalski’s horse. By contrasting domesticated species with their wild relatives, researchers made sense of how organic entities as distinctive as rice, tomatoes and the dogs got to be tamed.

With no truly wild horses to study, Orlando’s group analyzed DNA from 29 horse bones found in the Siberian permafrost and dating from 16,000 and 43,000 years back, and contrasted it with DNA from five advanced domesticated breeds.

A few genes in today’s horses were missing overall from the antiquated ones, indicating they emerged from late transformations. Among them: a short-distance “speed gene” that pushes each Kentucky Derby champ.

Geneticists not included in the study proposed that examining equine DNA from around the time of domestication, instead of centuries back, may demonstrate more evidently what hereditary changes happened as horses were domesticated.

“Contrasting aged genomes with present day genomes is precarious,” said Arne Ludwig of the Leibniz Institute for Zoo and Wildlife Research in Berlin.

Scientists Discover the Gene That Can Transform Wild Horses into Domestic Ones

December 16, 2014 By Rebecca McGhee Leave a Comment

Researchers discovered that DNA changes can turn an ancient horse into today’s Secretariats. It unveils that almost 125 genes are responsible for the process of equine domestication.

Beth Shapiro, co author of the study states that this is the most comprehensive list of gene candidate. Generally, humans who love domestic horses prefer these genes in horses. The extensive lists of these genes also play a significant role in the development of bones and muscles. Hence, it uncovers the genes transform wild horses into a domestic one.

These 125 genes are associated with muscles, coordination and cardiac strength. Especially the gene found in brain is associated with the domestic behavior of horses. It increases the fear response, learning and agreeableness in the wild horse. Usually, ancient breeders favored these characteristics of horses a lot.

Moreover, the study unearthed that the entire procedure of domestication provide a great help in the collection of lethal gene mutation. These deadly genes are not present in the modern horses any more.

The geneticists who are not included in the study propose that examination of equine DNA evidently demonstrates the genetic alteration of tamed horse.

Luidovic Orlando, the author of the report state that these genes are the essential for the transformation of wild animals into more passive domestic ones.

The study published in the Journal of Proceedings of the National Academy of Sciences.

Researcher Proves: Birds and Turtles Once Had Teeths.

December 15, 2014 By Brian Galloway Leave a Comment

At last, a new research unveils the reason why birds have teeth instead of beaks. The report demonstrates that birds lost its teeth nearly 116 million years ago.

Scientists discovered that Archaeopteryx which is the ancestor of the modern bird once had a set of teeth. The remnants of the bird found from Germany shows that birds emerged from tooth reptiles. The fossil became the basis of the entire research.

Afterwards, researchers tried to figure out the reason behind the loss of teeth. They closely analyzed the genetic structure of the birds in order to find out the reason.

Later on, the study shows that the genetic mutation in the birds is responsible for the loss of teeth. The scientists informed that six genes in birds give birth to teeth in birds.

Generally, these genes form enamel and dentin in vertebrates. Enamel is the outer side of the tooth, whereas dentin is the material present inside the tooth. Enamel is relatively stronger as compared to the dentin. The end of the production of enamel is the chief reason of the loss of teeth.

However, these six genes are inactive in modern birds. Surprisingly, birds are not the only one that lost teeth. A few other mammals such as turtle, whales and pangolins also lost teeth. These animals developed other means of feeding as a substitute of teeth.

Mark Springer, one of the main researchers of the report stated that the presence of these inactive mutation propose the birds lost teeth nearly 116 million years ago.

Scientists Sequenced A 45000-Year-Old Man’s Genome

October 23, 2014 By Rebecca McGhee Leave a Comment

The DNA of a 45000 year old bone of a Siberian man has been recently examined by the researchers to find out when human and Neanderthals first interbred. On record, this is an oldest genome sequence of Homo sapiens exposing a mysterious population that may once have spanned northern Asia. The study is published in the Nature journal.

The oldest human genome also revealed that the closest extinct relatives of the modern humans were the Neanderthals who lived in Europe and Asia and vanished around 40,000 years ago. The Neanderthals interbred with ancestors of modern humans when modern humans began spreading out of Africa and today 1.5 to 2.1 percent of the DNA of anyone living outside Africa is Neanderthal in origin, study reveals.

“It remains vague when interbreeding between Neanderthals and modern humans happened. But it probably ranged between 37000 to 86000 years ago,” researchers stated.

The researchers examined the bone (human left femur), discovered by Nikolai Peristov, an artist and mammoth ivory collector on the left bank of the river Irtysh near the settlement of Ust’-Ishim in western Siberia in 2008. The age of the man’s bone to be is about 45,000 years old, researchers stated.

Janet Kelso, co-author of the study and a computational biologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, told Live Science, “This is the earliest directly dated modern human outside of Africa and the Middle East, and the oldest modern human [genome] to have been sequenced.”

Formerly, the researchers had proposed modern humans firstly populated Asia by traveling towards southern, coastal route that gave rise to the present-day people of Oceania, while a later, more northern migration, gave rise to mainland Asians. Kelson stated, “the researchers’ evidence for the modern human presence in Siberia 45,000 years ago specifies that the early modern humans were not just migrated to Eurasia through a southern route as previously suggested.”

The researchers further examined the carbon and nitrogen isotopes present in the man’s bone proposes that he ate C3 plants, which rule cooler, wetter, cloudier regions such as garlic, eggplants, pears, beans and wheat as well as animals that also dined on C3 plants. Though, the study analysis reveals that he might have eaten aquatic foods like fresh water fish.

The DNA analysis of mans’s bone revealed that the he was closely related to present-day Asians and to early Europeans. “From this we conclude that the population to which the Ust’-Ishim individual belonged diverged from the ancestors of present-day Europeans and Asians before, or at around the same time as, these groups diverged from one another,” Kelso said.

The researchers believed that 45,000 years old man carried a similar level of Neanderthal ancestry as present-day Eurasians and the Neanderthal genes moved into the ancestors of this man 7,000 to 13,000 years before he lived.

The results of the study propose that modern humans and Neanderthals interbred around 50,000 to 60,000 years ago, “which is close to the time of the major expansion of modern humans out of Africa and the Middle East,” Kelso added.

Monarch Butterflies Migrated Long Distances Like Marathoners

October 2, 2014 By Jason Leathers Leave a Comment

Monarch butterflies can be found throughout the world, although only in North America they make a magnificent mass migration. The researcher have sequenced 90 butterfly genomes, and discovered that there is only one gene which is responsible for the capability of butterflies to migrate long distances like marathoners. The study findings propose that the monarch butterflies are evolved with more efficient muscles that help them to fly so far.

A recent genetic analysis published this week in the Nature journal stating that the intimates of the contemporary monarchs initially dispersed out North America, instead of central or South America, as formerly believed.

However, Marcus Kronforst, University of Chicago’s biologist confesses that he along with his fellow colleagues firstly discovered evolutionary proofs hard to accept. He stated in his interview with BBC News, “It really took lots of convincing,” though, the findings portray how genetics could elaborate the origins of a species’ traits on a level far more fundamental than, say, Rudyard Kipling’s “Just So Stories,” said the University of Exeter’s Richard H. ffrench-Constant.

H. ffrench-Constant (not involved in the project), stated in a Nature journal; “Butterflies are leading a revival in our understanding of the molecular basis of natural selection.”

Different patterns of alteration in genomes are analyzed by researchers to conclude that North American butterflies are nearby to their ancestral roots of evolutionary tree.

The researchers assumed that, the travelling Monarchs originated in Central or South America, and established themselves in North America. But the latest proof indicates that, the species got its start in Southern United States or Mexico, perhaps 1 million to 2 million years ago, said by Kronforst.

The butterflies most likely to followed a short range traveling pattern. The researchers says that, North American population began to expand about 20,000 years ago, at the end of the Last Glacial Maximum, when butterflies could more readily spread on milkweed crowd plants in the American Midwest.

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