Millions of years before scientists created genetically modified Atlantic salmon with genes from two other fish, nature created genetically modified smelt with a gene from herring, growing evidence shows.
And now the Canadian scientists who first proposed that controversial idea say they have a hunch how nature might have done it.
A new study by Queen’s University researchers Laurie Graham and Peter Davies finds “conclusive” evidence for the controversial idea that the antifreeze gene that helps rainbow smelt survive icy coastal waters originally came from herring and was somehow stolen by smelt about 20 million years ago.
They propose in their new paper in Trends in Genetics that this could have happened through a process quite similar to the way genes are sometimes transferred from one species to another by scientists in the lab today.
Stealing genes from other species
Genes are normally passed on from parents to offspring. But in recent decades, scientists discovered they can also “jump” or be “stolen” from one species to another outside normal reproduction — a process called horizontal gene transfer or lateral gene transfer.
It’s something that happens frequently among microbes such as bacteria — so frequently that Canadian scientist W. Ford Doolittle suggested it might explain a big part of life’s history on Earth.
Laurie Graham, a research associate at Queen’s University, said when she and Peter Davies first proposed that horizontal gene transfer had happened in fish more than a decade ago, they had a hard time getting the paper published. (Laurie Graham)
In more complex organisms such as fish and people, certain virus-like DNA sequences called “transposable elements” or “transposons” are also known to jump from species to species.
But the same hadn’t been seen for useful genes that code for things like proteins. That’s because genes in multicellular organisms can only be transmitted from generation to generation if they specifically get into reproductive cells such as eggs or sperm.
Davies is a professor and Canada Research Chair in Protein Engineering at Queen’s University. Graham is a research associate in his lab.
When the two first realized more than a decade ago that the herring and smelt must have shared their antifreeze protein via horizontal gene transfer, it was the first time anyone had suggested that a vertebrate — a complex animal with a backbone — had transferred such a gene to another vertebrate. That made it quite controversial.
“We had a really hard time finding a journal to take our first paper,” recalled Graham. “The reviewers were not exactly kind, and there was a lot of doubt.”
Graham had been originally examining different kinds of antifreeze proteins, not just in fish but also insects, bacteria, plants and small soil creatures called springtails.
Most of them appeared to arise from a common ancestor, with a similar structure in closely related animals.
Herring are unloaded from a fishing boat in Rockland, Maine, in 2015. Both Pacific and Atlantic herring have an antifreeze gene that helps them survive in icy coastal waters. (Robert F. Bukaty/The Associated Press)
But that wasn’t the case for herring and smelt, which are so distantly related that the last time they shared an ancestor was 250 million years ago, about the time the first dinosaurs arose.
“Every other gene we’ve looked at in these two species, it tends to be quite different,” Graham said.
Meanwhile, she added, closer cousins don’t have the antifreeze protein that Atlantic herring, Pacific herring and rainbow smelt are known to share.
“We’ve got other fish that are more closely related to these species that make completely different kinds of antifreeze protein. So this doesn’t really make sense on an evolutionary basis if everybody’s inheriting their antifreeze protein from their ancestors.”
Skeptics weren’t convinced, so the researchers looked for more evidence. Closely related fish such as different types of smelt tend to have the same genes in the same order. And the researcher found that was the case — except for the antifreeze gene, which was found between two genes that are normally next to each other in other smelt.
“That’s what you would expect when you have a gene that’s just sort of been pasted into a genome through horizontal gene transfer.”
Then, recently, the researchers heard that the genome of Atlantic herring was published in a public database.
They decided to take a closer look.
‘One of the take-home lessons here is that this genetic modification is actually happening in nature,’ said Peter Davies, professor and Canada Research Chair in Protein Engineering at Queen’s University. (Peter Davies)
Remember those transposable elements that often jump between organisms? They can also be used as a fingerprint for a particular organism. Herring have certain transposable elements pasted hundreds of times all over their genome, including in and around their eight antifreeze genes.
When the researchers looked at the smelt’s single antifreeze gene, it had three of those herring transposable elements attached, Graham said. “So it was like a little tag to say, ‘Hey, I’m from herring.'” Those transposable elements weren’t found anywhere else in the smelt.
The researchers say it’s conclusive evidence that the antifreeze gene moved between the two fish via horizontal gene transfer and that it went from herring to smelt and not vice versa.
How did the gene jump species?
When the researchers’ previous papers went through peer review, one of the questions reviewers had was how the gene might have moved between species, so they sought to come up with a hypothesis.
One possibility, they thought, was it might be similar to techniques used in the lab to create genetically modified animals. One called “sperm-mediated gene transfer” involves mixing sperm with the DNA you want to introduce, then using it to fertilize an egg.
“And we thought, ‘Well, couldn’t this also happen in nature?” Graham recalled.
Fish and many other marine animals have external fertilization, where eggs and sperm — known as milt — are released into the water at the same time in massive quantities during spawning, and some of them combine to produce offspring.
[embedded content]
Graham noted that when herring spawn on Canada’s Atlantic and Pacific coasts, “you can actually see the ocean is sort of stained white from all of the milt that the male herring are releasing.”
The sperm breaks apart after a few hours, releasing DNA into the water. And the researchers proposed that during one of these events, herring DNA may have found its way into rainbow smelt eggs or sperm.
Graham acknowledges there’s no way to prove that — “not unless we had a time machine.”
But if that is the way the genes were transferred, it has probably happened with other fish genes also, Davies suggested, and scientists should start looking for other examples.
The other implication is that genetically modified organisms, which have been characterized by activists as “Frankenfoods”, might not be so unnatural.
“One of the take-home lessons here is that this genetic modification is actually happening in nature,” Davies said. “Not very often — it’s probably quite rare — but maybe we shouldn’t be so alarmed at this. It’s actually more of a natural event than we previously thought.”
What other scientists think
Garth Fletcher, professor emeritus and head of the ocean sciences department at Memorial University, is the co-inventor of Aquabounty’s genetically modified salmon (but not through sperm-mediated gene transfer) and has previously collaborated with Davies comparing antifreeze proteins in fish. He wasn’t involved in the new study.
Fletcher doesn’t think the research will reassure those opposed to GMOs.
He says it’s significant that the researchers have gotten to the point where they feel their evidence for horizontal gene transfer in this controversial case is so strong. He credited new molecular genetic techniques with making it possible.
“Twenty years ago, you couldn’t have done this stuff.”
Luis Boto, head scientist in the evolutionary biology department at the National Museum of Natural Sciences in Madrid, has been tracking the evidence for horizontal gene transfer in complex organisms, and said the new genetic tools will allow scientists to explore how common this is.
“This paper opens the door to an important research field in that sequencing of new fish genomes will provide us with interesting findings,” he added in an email, “and will allow us to understand more about the possible importance of horizontal gene transfer in the evolution of animals.”
He said evidence for horizontal gene transfer in vertebrates remains rare, but the new paper offers “important support” for the case of it happening between herring and smelt.
Gane Ka-Shu Wong, a University of Alberta biology professor, is also convinced by the study and thinks the proposed way the gene moved from herring to smelt is plausible.
While such horizontal gene transfer events seem rare in complex organisms, if they help the organism survive, they could make a big difference, he said.
“My guess is that a lot of a lot of important evolutionary events may have been driven by some sort of horizontal gene transfer.”
More than 40 trillion gallons of rain drenched the Southeast United States in the last week from Hurricane Helene and a run-of-the-mill rainstorm that sloshed in ahead of it — an unheard of amount of water that has stunned experts.
That’s enough to fill the Dallas Cowboys’ stadium 51,000 times, or Lake Tahoe just once. If it was concentrated just on the state of North Carolina that much water would be 3.5 feet deep (more than 1 meter). It’s enough to fill more than 60 million Olympic-size swimming pools.
“That’s an astronomical amount of precipitation,” said Ed Clark, head of the National Oceanic and Atmospheric Administration’s National Water Center in Tuscaloosa, Alabama. “I have not seen something in my 25 years of working at the weather service that is this geographically large of an extent and the sheer volume of water that fell from the sky.”
The flood damage from the rain is apocalyptic, meteorologists said. More than 100 people are dead, according to officials.
Private meteorologist Ryan Maue, a former NOAA chief scientist, calculated the amount of rain, using precipitation measurements made in 2.5-mile-by-2.5 mile grids as measured by satellites and ground observations. He came up with 40 trillion gallons through Sunday for the eastern United States, with 20 trillion gallons of that hitting just Georgia, Tennessee, the Carolinas and Florida from Hurricane Helene.
Clark did the calculations independently and said the 40 trillion gallon figure (151 trillion liters) is about right and, if anything, conservative. Maue said maybe 1 to 2 trillion more gallons of rain had fallen, much if it in Virginia, since his calculations.
Clark, who spends much of his work on issues of shrinking western water supplies, said to put the amount of rain in perspective, it’s more than twice the combined amount of water stored by two key Colorado River basin reservoirs: Lake Powell and Lake Mead.
Several meteorologists said this was a combination of two, maybe three storm systems. Before Helene struck, rain had fallen heavily for days because a low pressure system had “cut off” from the jet stream — which moves weather systems along west to east — and stalled over the Southeast. That funneled plenty of warm water from the Gulf of Mexico. And a storm that fell just short of named status parked along North Carolina’s Atlantic coast, dumping as much as 20 inches of rain, said North Carolina state climatologist Kathie Dello.
Then add Helene, one of the largest storms in the last couple decades and one that held plenty of rain because it was young and moved fast before it hit the Appalachians, said University of Albany hurricane expert Kristen Corbosiero.
“It was not just a perfect storm, but it was a combination of multiple storms that that led to the enormous amount of rain,” Maue said. “That collected at high elevation, we’re talking 3,000 to 6000 feet. And when you drop trillions of gallons on a mountain, that has to go down.”
The fact that these storms hit the mountains made everything worse, and not just because of runoff. The interaction between the mountains and the storm systems wrings more moisture out of the air, Clark, Maue and Corbosiero said.
North Carolina weather officials said their top measurement total was 31.33 inches in the tiny town of Busick. Mount Mitchell also got more than 2 feet of rainfall.
Before 2017’s Hurricane Harvey, “I said to our colleagues, you know, I never thought in my career that we would measure rainfall in feet,” Clark said. “And after Harvey, Florence, the more isolated events in eastern Kentucky, portions of South Dakota. We’re seeing events year in and year out where we are measuring rainfall in feet.”
Storms are getting wetter as the climate change s, said Corbosiero and Dello. A basic law of physics says the air holds nearly 4% more moisture for every degree Fahrenheit warmer (7% for every degree Celsius) and the world has warmed more than 2 degrees (1.2 degrees Celsius) since pre-industrial times.
Corbosiero said meteorologists are vigorously debating how much of Helene is due to worsening climate change and how much is random.
For Dello, the “fingerprints of climate change” were clear.
“We’ve seen tropical storm impacts in western North Carolina. But these storms are wetter and these storms are warmer. And there would have been a time when a tropical storm would have been heading toward North Carolina and would have caused some rain and some damage, but not apocalyptic destruction. ”
Associated Press climate and environmental coverage receives support from several private foundations. See more about AP’s climate initiative here. The AP is solely responsible for all content.
It’s a dinosaur that roamed Alberta’s badlands more than 70 million years ago, sporting a big, bumpy, bony head the size of a baby elephant.
On Wednesday, paleontologists near Grande Prairie pulled its 272-kilogram skull from the ground.
They call it “Big Sam.”
The adult Pachyrhinosaurus is the second plant-eating dinosaur to be unearthed from a dense bonebed belonging to a herd that died together on the edge of a valley that now sits 450 kilometres northwest of Edmonton.
It didn’t die alone.
“We have hundreds of juvenile bones in the bonebed, so we know that there are many babies and some adults among all of the big adults,” Emily Bamforth, a paleontologist with the nearby Philip J. Currie Dinosaur Museum, said in an interview on the way to the dig site.
She described the horned Pachyrhinosaurus as “the smaller, older cousin of the triceratops.”
“This species of dinosaur is endemic to the Grand Prairie area, so it’s found here and nowhere else in the world. They are … kind of about the size of an Indian elephant and a rhino,” she added.
The head alone, she said, is about the size of a baby elephant.
The discovery was a long time coming.
The bonebed was first discovered by a high school teacher out for a walk about 50 years ago. It took the teacher a decade to get anyone from southern Alberta to come to take a look.
“At the time, sort of in the ’70s and ’80s, paleontology in northern Alberta was virtually unknown,” said Bamforth.
When paleontogists eventually got to the site, Bamforth said, they learned “it’s actually one of the densest dinosaur bonebeds in North America.”
“It contains about 100 to 300 bones per square metre,” she said.
Paleontologists have been at the site sporadically ever since, combing through bones belonging to turtles, dinosaurs and lizards. Sixteen years ago, they discovered a large skull of an approximately 30-year-old Pachyrhinosaurus, which is now at the museum.
About a year ago, they found the second adult: Big Sam.
Bamforth said both dinosaurs are believed to have been the elders in the herd.
“Their distinguishing feature is that, instead of having a horn on their nose like a triceratops, they had this big, bony bump called a boss. And they have big, bony bumps over their eyes as well,” she said.
“It makes them look a little strange. It’s the one dinosaur that if you find it, it’s the only possible thing it can be.”
The genders of the two adults are unknown.
Bamforth said the extraction was difficult because Big Sam was intertwined in a cluster of about 300 other bones.
The skull was found upside down, “as if the animal was lying on its back,” but was well preserved, she said.
She said the excavation process involved putting plaster on the skull and wooden planks around if for stability. From there, it was lifted out — very carefully — with a crane, and was to be shipped on a trolley to the museum for study.
“I have extracted skulls in the past. This is probably the biggest one I’ve ever done though,” said Bamforth.
“It’s pretty exciting.”
This report by The Canadian Press was first published Sept. 25, 2024.
TEL AVIV, Israel (AP) — A rare Bronze-Era jar accidentally smashed by a 4-year-old visiting a museum was back on display Wednesday after restoration experts were able to carefully piece the artifact back together.
Last month, a family from northern Israel was visiting the museum when their youngest son tipped over the jar, which smashed into pieces.
Alex Geller, the boy’s father, said his son — the youngest of three — is exceptionally curious, and that the moment he heard the crash, “please let that not be my child” was the first thought that raced through his head.
The jar has been on display at the Hecht Museum in Haifa for 35 years. It was one of the only containers of its size and from that period still complete when it was discovered.
The Bronze Age jar is one of many artifacts exhibited out in the open, part of the Hecht Museum’s vision of letting visitors explore history without glass barriers, said Inbal Rivlin, the director of the museum, which is associated with Haifa University in northern Israel.
It was likely used to hold wine or oil, and dates back to between 2200 and 1500 B.C.
Rivlin and the museum decided to turn the moment, which captured international attention, into a teaching moment, inviting the Geller family back for a special visit and hands-on activity to illustrate the restoration process.
Rivlin added that the incident provided a welcome distraction from the ongoing war in Gaza. “Well, he’s just a kid. So I think that somehow it touches the heart of the people in Israel and around the world,“ said Rivlin.
Roee Shafir, a restoration expert at the museum, said the repairs would be fairly simple, as the pieces were from a single, complete jar. Archaeologists often face the more daunting task of sifting through piles of shards from multiple objects and trying to piece them together.
Experts used 3D technology, hi-resolution videos, and special glue to painstakingly reconstruct the large jar.
Less than two weeks after it broke, the jar went back on display at the museum. The gluing process left small hairline cracks, and a few pieces are missing, but the jar’s impressive size remains.
The only noticeable difference in the exhibit was a new sign reading “please don’t touch.”
