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Image Credit: © Robert Zingg, Zoo Zurich

DNA of Tiny Lemurs Shows Big Changes in Madagascar’s Landscape

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Image Credit: © Robert Zingg, Zoo Zurich

Scientists comparing the genes of five teeny lemur species found that, once upon a time, the animals’ disparate habitats were all connected. They published their findings in the Proceedings of the National Academy of Sciences.

All 24 species of mouse lemurs (genus Microcebus) are primates descended from a common ancestor in the forests of Madagascar more than 10 million years ago. In the intervening time, the species have scattered across the island. They still look a lot alike from the outside, but each species has adapted to its own environment—changes that left a mark in the lemurs’ genes.

Adorable, hardy, fast-breeding, and unique to their environment, mouse lemurs are a geneticist’s dream subject. Female mouse lemurs reach sexual maturity when they’re just 12 months old. This means that their generations are short; or, to put it another way, they evolve much more rapidly than many other mammals.

Paper co-author Steve Goodman of The Field Museum in Chicago has spent the last 30 years studying Madagascar’s wildlife. He and his colleagues are working to piece together the natural history of the island itself by studying the animals that live there. For this study, they compared the genetic codes of five different mouse lemur species. (One of those species, Microcebus lehilahytsara has special significance for Goodman: “lehilahytsara” is Malagasy for “good man.” In English, the species is called Goodman’s mouse lemur, for the biologist’s many scientific contributions on the island.)

Goodman's mouse lemur. Image Credit: © Robert Zingg, Zoo Zurich

 
Analysis of the lemurs’ DNA showed that the species were still genetically close to one another. “That suggests that their ancestors were able to disperse across forested habitat that no longer exists,” Goodman said. He and his colleagues believe the now-separate east and west sides of the island were likely linked by a patchwork of forests.

Looking back in time through changes in the lemurs' DNA, the researchers could identify when the species split from one another and, consequently, what might have been happening on the island to make that possible.

A longstanding theory of the island's biogeography holds that it was the arrival of humans thousands of years ago that triggered the ecological shift. Yet the lemurs' DNA showed that the species had clearly diverged long before then, indicating that the landscape was already on the move by the time we arrived. It seems that natural climate change had a hand in the slow geographic shift.

“Madagascar is one of the top conservation priorities in the world,” Goodman said. “All of the native land mammals on Madagascar occur nowhere else in the world. This study is important because it sheds light upon the long-term life history of Madagascar, before human colonization. It helps us understand change.”

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Animals
25 Shelter Dogs Who Made It Big
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Focus Features

If you’ve been thinking of adding a four-legged friend to your brood and are deciding whether a shelter dog is right for you, consider this: Some of history’s most amazing pooches—from four-legged movie stars to heroic rescue dogs—were found in animal shelters. In honor of Adopt-a-Shelter-Dog Month, here are 25 shelter dogs who made it big.

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This High-Tech Material Can Change Shape Like an Octopus
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iStock

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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