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Matthew J Parker, Wikimedia Commons // CC BY-SA 3.0
Matthew J Parker, Wikimedia Commons // CC BY-SA 3.0

How Scientists Use Old Museum Specimens to Make New Findings

Matthew J Parker, Wikimedia Commons // CC BY-SA 3.0
Matthew J Parker, Wikimedia Commons // CC BY-SA 3.0

More and more researchers are making new discoveries using old museum specimens. By digging through archives and collections, they've identified scores of new species, including the teddy bear–like olinguito and the Ruth Bader Ginsberg mantis.

Now, scientists examining cyanobacteria found during an expedition in Antarctica more than a century ago have made a surprising find: It looks an awful lot like the bacteria living there today. Their report on the bacteria’s stability appears in the Proceedings of the Royal Society B.

Cyanobacteria are itsy-bitsy organisms that have occupied Earth’s fresh and salt water for more than 3.5 million years. Also known (inaccurately) as blue-green algae, these single-celled microbes grow in clumps, balls, and sheets all over the world—even in the punishing cold of Antarctica.

Microscope image of Tolypothrix cyanobacteria
Tolypothrix cyanobacteria under a microscope.

The earliest expeditions to Antarctica had multiple goals, including scientific study. During the Discovery Expedition (1901–1904), Captain Robert Falcon Scott and his team fished a soggy mat of cyanobacteria from Lake Joyce. They brought the mat back to London’s Natural History Museum (NHM), where it was examined, pressed like a flower between sheets of paper, and shelved for safekeeping.

Fast-forward more than 100 years, and things aren’t looking so great for the Antarctic. Climate change is melting icecaps, changing the landscape, and altering plants’ and animals’ behavior and evolution. Researchers with NHM and the University of Waikato wondered if the same was true for the continent’s bacteria.

Anne Jungblut and Ian Hawes journeyed back down to Lake Joyce, where they used drills, cameras, and sediment traps to collect new cyanobacteria samples. Back in London, they retrieved Captain Scott’s algae mats from the archives. They compared the old and new samples, inside and out, scouring the mats for microbe fossils and sequencing their genes.

The results suggested that not much has been going on at Lake Joyce this past hundred years. The two groups of bacteria were remarkably similar, comprising the same species in the same proportions.

This could be good news, the researchers say. "We suggest that this relates to Antarctic freshwater organisms requiring a capacity to withstand diverse stresses," they write, "and that this could also provide a degree of resistance and resilience to future climatic-driven environmental change in Antarctica."

As genetic testing technology improves, museum-based discoveries like this one become more and more common. Biologist Evon Hekkala, of Fordham University, tells Mental Floss, "We are seeing time and time again (no pun intended!), that museum collections originally made for exploratory purposes can take on new and critical roles in helping us to understand the fine details of how living things are responding to our rapidly changing environment. They have helped in some cases to confirm that human activities are driving the loss of genetic diversity and in other cases to exonerate us. This paper is a nice example where we have a comparison across time that can help us to understand how resilient certain living things can be in the face of change. I always say that with museum collections time travel really is possible!"

Hekkala has herself made discoveries using museum specimens. She identified a new crocodile species lurking in the drawers of the American Natural History Museum (AMNH) when she took samples from two crocodile specimens collected from different sides of the Congo River, as she recounts in a recent episode of the AMNH video series Shelf Life: "I was dumbfounded when I looked at the DNA sequence. It turns out that one specimen represents the Nile crocodile species that we all know and love, and the other represents a completely separate species of crocodile. In fact, they’re so distinct that they’re not even each other’s closest relatives. They haven't exchanged genes in millions of years."

Hekkala says museum collections are more important than ever as climate change, deforestation, and habitat loss destroy our planet’s plants and animal populations: "These specimens represent an irreplaceable resource that can never be re-acquired."

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What Causes Sinkholes?
Mark Ralston/AFP/Getty Images
Mark Ralston/AFP/Getty Images

This week, a sinkhole opened up on the White House lawn—likely the result of excess rainfall on the "legitimate swamp" surrounding the storied building, a geologist told The New York Times. While the event had some suggesting we call for Buffy's help, sinkholes are pretty common. In the past few days alone, cavernous maws in the earth have appeared in Maryland, North Carolina, Tennessee, and of course Florida, home to more sinkholes than any other state.

Sinkholes have gulped down suburban homes, cars, and entire fields in the past. How does the ground just open up like that?

Sinkholes are a simple matter of cause and effect. Urban sinkholes may be directly traced to underground water main breaks or collapsed sewer pipelines, into which city sidewalks crumple in the absence of any structural support. In more rural areas, such catastrophes might be attributed to abandoned mine shafts or salt caverns that can't take the weight anymore. These types of sinkholes are heavily influenced by human action, but most sinkholes are unpredictable, inevitable natural occurrences.

Florida is so prone to sinkholes because it has the misfortune of being built upon a foundation of limestone—solid rock, but the kind that is easily dissolved by acidic rain or groundwater. The karst process, in which the mildly acidic water wears away at fractures in the limestone, leaves empty space where there used to be stone, and even the residue is washed away. Any loose soil, grass, or—for example—luxury condominiums perched atop the hole in the ground aren't left with much support. Just as a house built on a weak foundation is more likely to collapse, the same is true of the ground itself. Gravity eventually takes its toll, aided by natural erosion, and so the hole begins to sink.

About 10 percent of the world's landscape is composed of karst regions. Despite being common, sinkholes' unforeseeable nature serves as proof that the ground beneath our feet may not be as solid as we think.

A version of this story originally ran in 2014.

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DNA Analysis of Loch Ness Could Reveal the Lake's Hidden Creatures
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iStock

Stakeouts, sonar studies, and a 24-hour video feed have all been set up in an effort to confirm the existence of the legendary Loch Ness Monster. Now, the Associated Press reports that an international team of scientists will use DNA analysis to learn what's really hiding in the depths of Scotland's most mysterious landmark.

The team, led by Neil Gemmell, who researches evolutionary genetics at the University of Otago in New Zealand, will collect 300 water samples from various locations and depths around the lake. The waters are filled with microscopic DNA fragments animals leave behind as they swim, mate, eat, poop, and die in the waters, and if Nessie is a resident, she's sure to leave bits of herself floating around as well.

After extracting the DNA from the organic material found in the water samples, the scientists plan to sequence it. The results will then be compared to the DNA profiles of known species. If there's evidence of an animal that's not normally found in the lake, or an entirely new species, the researchers will hopefully spot it.

Gemmell is a Nessie skeptic, and he says the point of the project isn't necessarily to discover new species. Rather, he wants to create a genetic profile of the lake while generating some buzz around the science behind it.

If the study goes according to plan, the database of Loch Ness's inhabitants should be complete by 2019. And though the results likely won't include a long-extinct plesiosaur, they may offer insights about other invasive species that now call the lake home.

[h/t AP]

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