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Pig Carcasses Aren’t a Great Model for Studying Human Decay, Study Finds

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Like so many fields of science, forensics relies heavily on the use of animals as human stand-ins. But a new study calls the wisdom of that practice into question, since researchers have found drastically different decay patterns for the bodies of humans, pigs, and rabbits. The scientists recently presented their findings to the American Academy of Forensic Sciences.

Our bodies, like every organism on the planet, are in a constant state of decay. Our cells are in perpetual turnover, dying and being replaced. Once we die, that replacement stops, and other processes and actors take over. Bacteria and fungi flourish and spread, gradually breaking down our flesh. Bodies left out in the open attract invertebrate scavengers like maggots and beetles, and vertebrates like birds and raccoons turn up to take away what’s no longer needed.

The details of the process are both fascinating and important to understand, especially for the scientists who aid police in investigating deaths. But finding human bodies to study is pretty difficult (if you do it legally, anyway), and so researchers often look to the bodies of pigs and other non-human animals. 

But what’s true for a pig is not always true for a person. An interdisciplinary team of researchers at the University of Tennessee Forensic Anthropology Center (FAC) tracked the day-by-day breakdown of 15 human, 15 pig, and 15 rabbit bodies through spring, summer, and winter. (The FAC, more commonly known as the Body Farm, is one of the few places in the U.S. that provides researchers with access to decaying human bodies.)

They found great variation in the speed and manner in which species decayed. In spring, for example, human and pig bodies were fairly well-matched until about 25 days in, when the pig bodies started rapidly turning to skeletons. Rabbit bodies broke down slowly at first, then quite rapidly once the maggots set to work. One rabbit looked fine one day, but was partially reduced to a skeleton 24 hours later.

In summer, pigs decayed faster than people and rabbits, turning to skeletons within 12 days. In winter, for obvious reasons, the bodies were insect-free for the first 100 days, but had plenty of visits from larger scavengers. Those raccoons, opossums, birds, and skunks were far more interested in human bodies than those of rabbits or pigs.

“This strongly indicates a preference for the humans over the other species,” the authors report. They conclude that human decomposition is a lot less predictable than that of pigs, which is bad news for all those pig studies.

“This research provides guidance to lawyers and judges concerning the admissibility of testimony by anthropologists and entomologists,” said principal investigator and FAC director Dawnie Steadman in a press statement. “Now [they] may be asked in court which studies they used to base their estimate of postmortem interval, and if they are based on nonhuman studies, their testimony could be challenged.”

[h/t Forensic Magazine]

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This High-Tech Material Can Change Shape Like an Octopus
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Octopuses can do some pretty amazing things with their skin, like “see” light, resist the pull of their own sticky suction cups, and blend in seamlessly with their surroundings. That last part now has the U.S. Army interested, as Co.Design reports. The military branch’s research office has funded the development a new type of morphing material that works like an octopus’s dynamic skin.

The skin of an octopus is covered in small, muscular bumps called papillae that allow them to change textures in a fraction of a second. Using this mechanism, octopuses can mimic coral, rocks, and even other animals. The new government-funded research—conducted by scientists at Cornell University—produced a device that works using a similar principle.

“Technologies that use stretchable materials are increasingly important, yet we are unable to control how they stretch with much more sophistication than inflating balloons,” the scientists write in their study, recently published in the journal Science. “Nature, however, demonstrates remarkable control of stretchable surfaces.”

The membrane of the stretchy, silicone material lays flat most of the time, but when it’s inflated with air, it can morph to form almost any 3D shape. So far, the technology has been used to imitate rocks and plants.

You can see the synthetic skin transform from a two-dimensional pad to 3D models of objects in the video below:

It’s easy to see how this feature could be used in military gear. A soldier’s suit made from material like this could theoretically provide custom camouflage for any environment in an instant. Like a lot of military technology, it could also be useful in civilian life down the road. Co.Design writer Jesus Diaz brings up examples like buttons that appear on a car's dashboard only when you need them, or a mixing bowl that rises from the surface of the kitchen counter while you're cooking.

Even if we can mimic the camouflage capabilities of cephalopods, though, other impressive superpowers, like controlling thousands of powerful suction cups or squeezing through spaces the size of a cherry tomato, are still the sole domain of the octopus. For now.

[h/t Co.Design]

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Animals
25 Benefits of Adopting a Rescue Dog
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According to the ASPCA, 3.3 million dogs enter shelters each year in the United States. Although that number has gone down since 2011 (from 3.9 million) there are still millions of dogs waiting in shelters for a forever home. October is Adopt a Shelter Dog Month; here are 25 benefits of adopting a shelter dog.

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