Smithsonian.com

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In elementary school, we learn that caterpillars turn into butterflies and moths through a process called metamorphosis. But what really goes on within the hardened chrysalis has continued to puzzle scientists. Now, computer tomography scans have allowed researchers to peep in on the caterpillar-to-butterfly action taking place inside the chrysalis, The Scientist reports.

Previously, researchers hoping to learn about metamorphosis had to dissect the chrysalis, which killed the developing insect inside. The key breakthrough about this new technique, they say, is that it allows them to study living tissue as it grows and changes.

Using series of dead individuals provides snapshots of presumably sequential development, but it can be unclear whether one insect’s third day in a chrysalis is really the same developmentally as another’s. CT scans can provide a more complete picture of how development proceeds.

In this new study, the team scanned nine painted lady chrysalises. Four of the insects died during the experiment while the other five hatched. In their results, the researchers focused on data derived from one of the insects in particular that provided the most detailed scans.

Here’s a video the researchers put together of their caterpillar’s gradual development into butterfly:

Rather than rewriting the story of butterfly development, the researchers told The Scientist, this experiment fills in missing details. For example, The Scientist describes:

The trachea did become visible surprisingly fast, within 12 hours after pupation, indicating that the structures either are more fully formed in caterpillars than previously thought or form very rapidly in pupae. While the trachea and the intestines showed up remarkably clearly, the “soft, gooey bits,” such as muscles and the central nervous system, were unfortunately invisible, Garwood said.

Lepidopterists, the scientists who study butterflies and moths, are not the only insect researchers who can benefit from CT scans. Many other arthropods—including beetles, flies, bees, wasps, ants and fleas—also go through metamorphosis.

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Many runners pursue the sport for the reward that comes at the end of a race or long jog: the runner’s high. Researchers suspect that other animals adapted to run, like dogs, may experience this neurobiological response after a round of exercise, too. A group of University of Arizona researchers decided to test this hypothesis, publishing their results in the Journal of Experimental Biology.

The researchers decided to test how dogs, humans and ferrets experience the runner’s high, Discovery News writes. While dogs’ long, muscular legs are adapted for running, ferrets’ legs are not. Instead, those small carnivores tend to scamper around in short bursts.

The researchers made their human and animal subjects work out on a treadmill, then gaged the results by measuring levels of endocannabinoids, a type of neurotransmitter involved in a number of physiological processes and associated with sending reward signals to the brain.

Both the humans and the dogs’ levels of endocannabinoids spiked after their workout, but the ferrets lacked any measurable buzz. Though the researchers didn’t include cats in the study, Discovery writes, they suspect that felines, too, would experience a runner’s high.

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Photo: Christien Zenino

Climate change is changing the planet. Yes, it’s doing it in all those ways that you already know about: rising seas, rising temperatures, changing rainfall patterns, more extreme weather. But climate change is changing the planet in another dramatic way, too: It’s actually causing the entire crust of the Earth to shift. According to new research by Jianli Chen and colleagues, climate change–induced glacier melt and sea level rise have thrown the whole planet off-kilter.

The Earth is a ball that floats in space, and the Earth’s surface—the tectonic plates that make up the land—are like a shell that floats on the mantle below. Just like the hard chocolate coating can slip and slide on your soft serve ice cream, the crust of the Earth can slide over the mantle. This is different than continental drift. This is the whole surface of the planet moving as one. The rotation axis of the Earth stays steady, the land masses shift around it. The idea is known as “true polar wander,” and its occurrence is a part of the planet’s history.

The Earth is not a perfect sphere—it’s kind of fat at the middle—and changing how the mass on the surface is distributed changes how the tectonic plates sit in relation to the planet’s rotation axis. By melting Greenland and other glaciers, say the researchers, the Earth’s geographic North Pole has drifted to the east at around 2.4 inches each year since 2005. Nature:

From 1982 to 2005, the pole drifted southeast towards northern Labrador, Canada, at a rate of about 2 milliarcseconds — or roughly 6 centimetres — per year. But in 2005, the pole changed course and began galloping east towards Greenland at a rate of more than 7 milliarcseconds per year.

Seasonal shifts in how ice and water are spread around the world mean that the North Pole is always sort of wandering around. But drift triggered by climate change is new. It’s a sign that global warming isn’t just changing how we might live in the world, but the very face of the world itself.

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Photo: Ron Lute

Up on the roof of a government research building in Swift Current, Saskatchewan, the Canadian province that straddles Montana and North Dakota, Barbara Cade-Menun has a tarp filled with poo. Little brown pucks of cow manure that bake in the sun and freeze in the winter, where temperatures regularly drop below 5 degrees.

Cade-Menun and students are tracking how bacteria such as E. coli survive the harsh prairie winters. “[I]f E. coli can survive here, they’ll survive anywhere,” says the CBC. The research has important implications for people living in or downstream of agricultural regions as E. coli in your water can be a very bad thing.

Thirteen years ago this month tragedy struck a small Ontario, Canada, town when E. coli bacteria got into the water system. In Walkerton, Ontario, a town of 5,000 people, 2,300 fell ill suffering from “bloody diarrhea, vomiting, cramps and fever.” Seven people died. Over time, the tragedy was traced to manure spread on a nearby farm that had managed to carry the E. coli bacteria through the ground and into the town’s water system. That, alongside regulatory missteps, caused the preventable disaster—the “most serious case of water contamination in Canadian history.”

Though steps have been taken in the region to prevent similar disasters in the future, there is still much that is unknown about how E. coli moves through a watershed. From her rooftop investigation Cade-Menun found that E. coli are sneaky little bacteria.

Cade-Menun and her colleagues found that when the temperature plummets the frozen manure pucks seem to be bacteria-free. But the bacteria aren’t dead, and when the spring warmth returns so too do the bacteria.

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Even the roof of the world is not immune to climate change. New research indicates that Mount Everest and its surrounding peaks are losing their ice cover, and that snowfall in the region has been declining since the 1990s amidst warming temperatures.

Over the past 50 years, the snow line has receded nearly 600 feet up the mountain and glaciers in the region have shrunk by 13 percent, the researchers report. Smaller glaciers, less than half a square mile, are melting the quickest and have shrunk by about 43 percent since the 1960s. Most glaciers in the national park, they found, are shrinking at an increasing rate.

The team arrived at these findings by surveying around 700 square miles surrounding Mount Everest and comparing the current conditions to past images reconstructed from satellite imagery and maps. They relied upon data collected by observatory stations and Nepal’s Department of Hydrology and Meteorology for calculating temperature fluctuations throughout the years. Since 1992, they found, the Everest region has increased in temperature by nearly two degrees Fahrenheit while snowfall decreased by almost four inches during that same period.

While the researchers cannot definitively link the changes seen on Mount Everest and its surroundings to increases in human-generated greenhouse gases, they strongly suspect climate change is the culprit behind their observations.

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