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."

9 Not-So-Pesky Facts About Termites

iStock.com/Thithawat_s
iStock.com/Thithawat_s

Termites get a lot of hate for chewing through buildings, but the little creatures are far more interesting—and ecologically valuable—than we often give them credit for. Unless, of course, you’re Lisa Margonelli, the author of Underbug: An Obsessive Tale of Termites and Terminology, a new book that explores their amazing world. Here are nine facts about the highly social—and occasionally pesky—insects that we learned from the book.

1. THERE ARE FAR MORE TERMITES THAN PEOPLE ON EARTH.

Termite queens live up to 25 years, and can lay somewhere around 30,000 eggs a day. As a result, a single mound can be home to millions of individuals at a time. While the numbers vary from study to study, scientists estimate that the biomass of all the termites in the world is at least as great as that of humans.

2. MOST TERMITES AREN’T PESTS.

Of the 2800 named termite species in the world, the majority have no interest in eating your house. Only 28 species are known to chow down on buildings and infrastructure. Most are actually very beneficial to their ecosystems, clearing dead wood, aerating the soil with their intricate tunnel systems, and enhancing plant growth. Researchers have found that contrary to being pests, networks of termite mounds can help make dry environments like savannas more resilient to climate change because of the way termite mounds store nutrients and moisture, among other benefits.

3. TERMITES ARE GOOD FOR CROPS.

Termites can help make soil more fertile. In one study, researchers in Australia found that fields that were home to ants and termites produced 36 percent more wheat, without fertilizer, compared to non-termite fields. Why? Termites help fertilize the soil naturally—their poop, which they use to plaster their tunnels, is full of nitrogen. Their intricate system of underground tunnels also helps rainfall penetrate the soil more deeply, which reduces the amount of moisture that evaporates from the dirt and makes it more likely that the water can be taken up by plants.

4. TERMITES HAVE VERY SPECIFIC ROLES IN THEIR COLONY.

Each termite colony has a queen and king termite (or several), plus workers and soldiers. This caste system, controlled by pheromones produced by the reigning queen, determines not just what different termites do in the colony but how they look. Queens and kings develop wings that, when they’re sexually mature, they use to fly away from their original nest to reproduce and start their own colony. Once they land at the site of their new colony, queens and kings snap off these wings, since they’ll spend the rest of their lives underground. Queens are also physically much larger than other castes: The largest type of termite, an African species called Macrotermes bellicosus, produces queens up to 4 inches long.

Unlike their royal counterparts, most workers and soldiers don’t have either eyes or wings. Worker termites, which are responsible for foraging, building tunnels, and feeding the other castes in the nest, are significantly smaller than queens. M. bellicosus workers, for instance, measure around 0.14 inches. Soldier termites are slightly bigger than workers, with large, sharp mandibles designed to slice up ants and other enemies that might invade the nest.

5. TERMITES ARE ONE OF THE FASTEST ANIMALS IN THE WORLD.

Apologies to cheetahs, but termites hold the record for world’s fastest animal movement. Panamanian termites can clap their mandibles shut at 157 miles per hour. (Compare that to the cheetah’s run, which tops out at about 76 miles per hour.) This quick action allows tiny termite soldiers in narrow tunnels to kill invaders with a single bite.

6. TERMITES ARE SKILLED ARCHITECTS.

In Namibia, quarter-inch-long termites of the genus Macrotermes can move 364 pounds of dirt and 3300 pounds of water each year total in the course of building their 17-foot-tall mounds. Relative to their size, that’s the equivalent of humans building the 163 floors of Dubai’s Burj Khalifa, no cranes required. And that’s not even the tallest termite mound around—some can be up to 30 feet high. More impressively, termites cooperate to build these structures without any sort of centralized plan. Engineers are now trying to replicate this decentralized swarm intelligence to build robots that could erect buildings in a similar fashion.

7. TERMITES BUILD THEIR OWN AIR CONDITIONING.

Some termites have developed an incredibly efficient method of climate control in the form of tall, above-ground mounds that sit above their nests. Organized around a central chimney, the structures essentially act as giant lungs, "breathing" air in and out as the temperature outside changes in relation to the temperature inside. Thanks to these convection cycles, termites keep underground temperatures in their nest between roughly 84°F and 90°F.

8. TERMITES ARE FARMERS.

Humans aren’t the only ones cultivating crops. Termites farm, too. They’ve been doing it for more than 25 million years, compared to humans’ 23,000 years. Some species of termite have evolved a symbiotic relationship with Termitomyces fungi, growing fungus in underground gardens for food. When they fly off to create a new colony, termite queens bring along fungus spores from their parent colony to seed the garden that will feed their new nest. Foraging termite workers go out and eat plant material that they can’t fully digest on their own, then deposit their feces on the fungus for it to feed on. They can then eat the fungus. They may also be able to eat some of the plant material after the fungus has sufficiently broken it down. The mutually beneficial relationship has led some scientists to suggest that the fungus, which is much larger in both size and energy production than the termites, could in fact be the one in control of the relationship, potentially releasing chemical pheromones that lead the termites to build the mound they live in together.

9. TERMITES ARE MICROBIAL GOLD MINES.

As scientists begin to understand the huge role that micobiomes play in both the human body and the rest of the world, termites provide a fascinating case study. About 90 percent of the organisms in termite guts aren’t found anywhere else on Earth. In their hindgut alone, they host as many as 1400 species of bacteria. These microbes are so efficient at converting the cellulose-rich wood and dead grass that termites eat into energy, scientists want to harness them to make biofuel from plants.

Want to learn more about termites? Get yourself a copy of Underbug on Amazon for $18.

This Live Stream Lets You Eavesdrop on Endangered Killer Whales' Conversations

iStock.com/Serega
iStock.com/Serega

Southern resident killer whales, which are usually found off the coasts of Washington, Oregon, and British Columbia, are an endangered species. If you're lucky, though, you might be able to hear a pod of the killer whales chattering away from the comfort of your own home. A website spotted by The Kansas City Star lets you live stream the calls of killer whales from your phone or laptop. Dubbed Orcasound, it uses hydrophones (underwater microphones) to pick up oceanic sounds from two areas off the coast of Washington.

On the website, listeners can choose between the two locations. One is the Orcasound Lab in Haro Strait, which is situated off the coast of Washington's San Juan Islands—the "summertime habitat" of this specific ecotype of whale, according to the website. The other location is Bush Point at the entrance to Puget Sound, where the whales pass through about once a month in search of salmon. However, that hydrophone is currently being repaired.

So what do orcas sound like? They're loud, and they do a whole lot of whistling, whining, and clicking. You can hear a snippet of what that sounds like in a four-minute podcast uploaded to the Orcasound site.

There’s no guarantee you’ll hear an orca, though. "Mostly you'll hear ships," the website notes, but there's also a chance you'll hear humpbacks in the fall and male harbor seals in the summer.

The live stream isn't just for educational purposes. It also serves as a citizen science project to help researchers continue their studies of southern resident killer whales, which are in danger of starvation as Chinook salmon, their main food source, die off.

The makers of Orcasound are urging listeners to email ihearsomething@orcasound.net anytime they hear killer whales or "other interesting sounds." They can also log their observations in a shared Google spreadsheet. Eventually, developers of the site hope to roll out a button that listeners can click when they hear a whale, to make the process easier for people to get involved.

[h/t The Kansas City Star]

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