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A rare disease among children is discovered in a 66-million-year-old dinosaur tumor – CNN

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Researchers at Tel Aviv University noticed unusual cavities in two tail segments of the hadrosaur, which were unearthed at the Dinosaur Provincial Park in southern Alberta, Canada.
They compared the vertebrae with the skeletons of two humans who were known to have a benign tumor called LCH (Langerhans cell histiocytosis), a rare and sometimes painful disease that affects children, mainly boys.
Hadrosaur vertebra.
“Diagnosing diseases in skeletal remains and fossils is complicated as in some cases different diseases leave similar marks on bones. LCH, however, has a distinctive appearance that fit to the lesions found in the hadrosaur,” said Dr. Hila May, head of the Biohistory and Evolutionary Medicine Laboratory, at TAU’s Sackler Faculty of Medicine.
The researchers used advanced, high-resolution CT scans to analyze the dinosaur tail fossils.
“New technologies,such as the micro CT scanning, enabled us to examine the … structure of the lesion and reconstruct the overgrowth as well as the blood vessels that fed it,” May told CNN.
An illustration of a type of hadrosaur.  An illustration of a type of hadrosaur.
“The micro and macro analyses confirmed that it was, in fact, LCH. This is the first time this disease has been identified in a dinosaur,” May said.
In humans, LCH is sometimes described as a rare form of cancer but May said that there are different opinions among experts as to whether it is definitively a cancer or not because in some cases its passes spontaneously.
“Most of the LCH-related tumors, which can be very painful, suddenly appear in the bones of children aged 2-10 years. Thankfully, these tumors disappear without intervention in many cases,” she said.
Hadrosaurs would have stood about 10 meters high and weighed several tons. They roamed in large herds 66 to 80 million years ago, the study, which published this week in the journal Scientific Reports said.

Dino diseases

Like us, dinosaurs got sick but evidence of disease and infection in the fossil record — a field known as paleopathology — has been scant.
However, there is evidence that tyrannosaurids, like the T-Rex, suffered from gout and that iguanodons may have had osteoarthritis. Cancer has proved more difficult for paleopathologists to diagnose but there is evidence that dinosaurs would have suffered from the disease, the study said.
Studying disease in fossils, independent of the species, is a complicated task. And it is even more complicated when dealing with those of animals that are extinct as we do not have a living reference, May explained.
Dr. Hila May holding a hadrosaur vertebraDr. Hila May holding a hadrosaur vertebra
The authors said the finding could help further evolutionary medicine — a new field of research that investigates the development and behavior of diseases over time.
Given that many of the diseases we suffer from come from animals, such as coronovirus, HIV and tuberculosis, May said understanding how they manifest themselves in different species and survive evolution can help find new and effective ways to treat them.
“When we know that a disease is independent of species or time, it means the mechanism that encourages its development is not specific to human behavior and environment, rather [it’s] a basic problem in an organism’s physiology,” May said.

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The Earliest Sex Between Different Human Ancestors May Have Occurred 700,000 Years Ago – ScienceAlert

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Our evolutionary history is full of inter-species sex.

Different human ancestor species seem to have mingled and mated far more than anthropologists previously realised. Neanderthals interbred with modern humans. Homo sapiens had sex with Denisovans.

And 700,000 years ago, according to a new study, a population of ancient humans mated with a distinct, unknown population that had separated from other human species at least 1 million years prior.

“This continues the story that we’ve been seeing in studies throughout the past decade: There’s lots more interbreeding between lots of human populations than we were aware of ever before,” Alan Rodgers, an anthropologist and the lead author of the new study, told Business Insider.

“This discovery has pushed the time depth of those interbreedings much farther back.”

According to his team’s research, published today in the journal Science Advances, the newly discovered interbreeding event took place in Eurasia, and it represents the earliest known example of mating between different populations of ancient humans.

The analysis, which compared DNA from Neanderthals, Denisovans, and modern humans from Europe and Africa, lends further credence to the idea that the our ancestors’ genes (and our own) came from myriad sources.

The oldest episode of interbreeding in the anthropological record

When geneticists finished sequencing the Neanderthal genome in 2010, they realised that Neanderthals had interbred with modern humans between 40,000 and 60,000 years ago.

Then a 2018 study revealed that Denisovans – which disappeared about 50,000 years ago – passed on some of their genes to Homo sapiens.

But the interbreeding event that Rodgers and his colleagues found was far, far older. In that case, a group of humans who were ancestors of both Neanderthals and Denisovans (the study authors nicknamed them “neandersovans”) interbred with their predecessor species about 744,000 years ago.

Those predecessors, in turn, were part of a”superarchaic” group in Eurasia that was between 20,000 and 50,000 people in size.

A major implication of the study, then, is that human populations migrated from Africa to Eurasia three times during our long evolutionary history: once 1.9 million years ago, again 700,000 years ago, and then a final time 50,000 years ago.

The first of these waves involved the “superarchaics”. Then the neandersovans followed 700,000 years ago; they likely separated from the modern human lineage before they migrated north, the study suggests.

As that second wave of ancestors moved into Eurasia, the researchers wrote, they likely “interbred with indigenous Eurasians, largely replaced them, and separated into eastern and western subpopulations – Denisovans and Neanderthals.”

Then many hundreds of thousands of years later, modern humans left Africa, interbreeding with Neanderthals – and eventually Denisovans, too – as they spread through Eurasia.

“These same events unfolded once again around 50,000 years ago as modern humans expanded out of Africa and into Eurasia, largely replacing the Neanderthals and Denisovans,” the study authors wrote.

A population of ‘superarchaic humans’

Rodgers’ team’s discovery came after they compared publicly available modern human DNA with ancient DNA. The analysis revealed at least four watershed moments in which genetic material passed from one human species to another over the last 1 million years.

Three of those moments matched the results other studies had already found. But the oldest instance was a new find.

In addition to representing the oldest evidence of human interbreeding on record, the finding is also surprising because but the two populations that mated were far less closely related than other human groups previously known to have interbred.

Whereas modern humans and Neanderthals had been on separate branches of the evolutionary tree for about 750,000 years when they interbred, the newly discovered population and the “neandersovans” had been separated for more than 1 million years.

Several mysteries remain, however. Rodgers’ team isn’t sure what ancient species the “superarchaic” population belonged to.

All they know is that genetic evidence suggests the superarchaics separated from our human lineage about 2 million years ago, and that ancient humans were living in Eurasia at the time the species separation occurred.

“We’ve got fossil evidence of humans in Eurasia that dates back to 1.85 million years old,” Rogers said.

At least two groups of human species, or taxa, lived in Eurasia during the time the superarchaics broke off from our lineage. One, Homo erectus, was the first of our ancestors to walk upright. The other possible taxon was Homo erectus’ younger cousin, Homo antecessor, which inhabited modern-day Spain.

“Any of those taxa might be the superarchaics,” Rodgers said. “Or they might be some taxon we don’t know about yet.”

But regardless of which group the superarchaics belonged to, Rodgers said, the new evidence of interbreeding offers a glimpse into an ancient time period that researchers know very little about.

“We’re just shedding light on an interval on human evolutionary history that was previously completely dark,” he said.

This article was originally published by Business Insider.

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University of Alberta scientist to participate in NASA Mars mission – CTV News

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EDMONTON —
Chris Herd might not be going to the Red Planet himself but he’ll play a key role in NASA’s Mars 2020 rover project slated to launch this summer.

Herd, a professor in the Department of Earth and Atmospheric Sciences at the University of Alberta, has been chosen to analyze rock samples collected and stored with the intention of bringing them back to Earth through future missions to Mars.

“It was around the age of 13 that I wanted to work on rocks from Mars,” said Herd. “I wanted to be there when the rocks came back so for me to be chosen to be involved in a big mission and NASA’s next big mission to Mars, and the fact that it’s going to be collecting samples that will eventually come back to Earth, that really is the most exciting thing.”

The project marks the first time Martian meteorite and rock will be collected and stored. The hope is that the samples will provide key information about the planet’s geological history.

“We think that Mars may have had the conditions right for life at one point … especially the rocks that we’re going to look at,” said Herd. “So eventually the idea is to bring these samples back and really pour over them and tell us whether these actually have evidence for ancient life in them or not.”

Herd is one of 10 experts and the only Canadian selected by NASA for the project.

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Earliest interbreeding event between ancient human populations discovered – HeritageDaily

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For three years, anthropologist Alan Rogers has attempted to solve an evolutionary puzzle. His research untangles millions of years of human evolution by analyzing DNA strands from ancient human species known as hominins.

Like many evolutionary geneticists, Rogers compares hominin genomes looking for genetic patterns such as mutations and shared genes. He develops statistical methods that infer the history of ancient human populations.

In 2017, Rogers led a study which found that two lineages of ancient humans, Neanderthals and Denisovans, separated much earlier than previously thought and proposed a bottleneck population size. It caused some controversy–anthropologists Mafessoni and Prüfer argued that their method for analyzing the DNA produced different results. Rogers agreed, but realized that neither method explained the genetic data very well.

“Both of our methods under discussion were missing something, but what?” asked Rogers, professor of anthropology at the University of Utah.

The new study has solved that puzzle and in doing so, it has documented the earliest known interbreeding event between ancient human populations–a group known as the “super-archaics” in Eurasia interbred with a Neanderthal-Denisovan ancestor about 700,000 years ago. The event was between two populations that were more distantly related than any other recorded. The authors also proposed a revised timeline for human migration out of Africa and into Eurasia. The method for analyzing ancient DNA provides a new way to look farther back into the human lineage than ever before.

“We’ve never known about this episode of interbreeding and we’ve never been able to estimate the size of the super-archaic population,” said Rogers, lead author of the study. “We’re just shedding light on an interval on human evolutionary history that was previously completely dark.”

An evolutionary tree including four proposed episodes of gene flow. The previously unknown event 744,372 years ago (orange) suggests interbreeding occurred between super-archaics and Neanderthal-Denisovan ancestors in Eurasia. Credit : Alan Rogers

The paper was published on Feb. 20, 2020, in the journal Science Advances.

Out of Africa and interbreeding

Rogers studied the ways in which mutations are shared among modern Africans and Europeans, and ancient Neanderthals and Denisovans. The pattern of sharing implied five episodes of interbreeding, including one that was previously unknown. The newly discovered episode involves interbreeding over 700,000 years ago between a distantly related “super-archaic” population which separated from all other humans around two million years ago, and the ancestors of Neanderthals and Denisovans.

The super-archaic and Neanderthal-Denisovan ancestor populations were more distantly related than any other pair of human populations previously known to interbreed. For example, modern humans and Neanderthals had been separated for about 750,000 years when they interbred. The super-archaics and Neanderthal-Denisovan ancestors were separated for well over a million years.

“These findings about the timing at which interbreeding happened in the human lineage is telling something about how long it takes for reproductive isolation to evolve,” said Rogers.

The authors used other clues in the genomes to estimate when the ancient human populations separated and their effective population size. They estimated the super-archaic separated into its own species about two million years ago. This agrees with human fossil evidence in Eurasia that is 1.85 million years old.

The researchers also proposed there were three waves of human migration into Eurasia. The first was two million years ago when the super-archaics migrated into Eurasia and expanded into a large population. Then 700,000 years ago, Neanderthal-Denisovan ancestors migrated into Eurasia and quickly interbred with the descendants of the super-archaics. Finally, modern humans expanded to Eurasia 50,000 years ago where we know they interbred with other ancient humans, including with the Neanderthals.

“I’ve been working for the last couple of years on this different way of analyzing genetic data to find out about history,” said Rogers. “It’s just gratifying that you come up with a different way of looking at the data and you end up discovering things that people haven’t been able to see with other methods.”

UNIVERSITY OF UTAH

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