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."

Why Is Pee Yellow?

Chloe Effron
Chloe Effron

WHY? is our attempt to answer all the questions every little kid asks. Do you have a question? Send it to why@mentalfloss.com.

Your body is kind of like a house. You bring things into your body by eating, drinking, and breathing. But just like the things we bring home to real houses, we don’t need every part of what we take in. So there are leftovers, or garbage. And if you let garbage sit around in your house or your body for too long, it gets gross and can make you sick. Your body takes out the garbage by peeing and pooping. These two things are part of your body’s excretory system (ECKS-krih-tore-eee SISS-tem), which is just a fancy way of saying “trash removal.” If your body is healthy, when you look in the toilet you should see brown poop and yellow pee.

Clear, light yellow pee is a sign that your excretory system and the rest of your body are working right. If your pee, or urine (YER-inn), is not see-through, that might mean you are sick. Dark yellow urine usually means that you aren’t drinking enough water. On the other hand, really pale or colorless pee can mean you might be drinking too much water! 

Your blood is filtered through two small organs called kidneys (KID-knees). Remember the garbage we talked about earlier? The chemicals called toxins (TOCK-sins) are like garbage in your blood. Your kidneys act like a net, catching the toxins and other leftovers and turning them into pee.

One part of your blood is called hemoglobin (HEE-moh-gloh-bin). This is what makes your blood red. Hemoglobin goes through a lot of changes as it passes through your body. When it reaches your kidneys, it turns yellow thanks to a chemical called urobilin (yer-ah-BY-lin). Urobilin is kind of like food coloring. The more water you add, the lighter it will be. That's why, if you see dark yellow pee in the toilet, it's time to ask your mom or dad for a cup of water. 

To learn more about pee, check out this article from Kids Health. 

Why Don’t We Fall Off the Earth?

Chloe Effron
Chloe Effron

WHY? is our attempt to answer all the questions every little kid asksHave a question? Send it to why@mentalfloss.com.

Do you know the saying “what goes up, must come down”? There’s a lot of truth to that. No matter how hard you hit that baseball or how high you get on the swings, you’re not going to make it into space (without a spaceship, of course). This is because of something called gravity (GRAV-it-ee). Gravity is the force that keeps you (and all your toys) from floating into space. 

The Earth’s gravity is a force that works kind of like a magnet. When you jump in the air, you come back down because gravity is pulling you towards the center of the Earth. Gravity does a lot more than just keep your feet on the ground. The strong pull of planets has created whole solar systems and galaxies. The Earth's gravity pulls in the Moon, which orbits (or circles) around it. Objects that orbit planets are called satellites (SAT-uh-lights). Some other planets have one or more moons of their own. The largest planet in our solar system, Jupiter, has 63 known moons! The Sun also has a gravitational (grav-uh-TAY-shun-ull) pull. It pulls all the planets in our solar system around it. Just like the Moon circles the Earth, the Earth circles the Sun.   

This force is something that all objects have—even you! The reason you don’t have tiny objects stuck to you is because you’re not big enough to have a strong enough pull. Even really big things like whales aren’t large enough to have a gravitational pull. Only really, really big things like stars, planets, and moons have it. 

The Moon is big enough to have its own pull. Its gravity tugs on the Earth's oceans. That's why we have ocean tides. But the Moon's gravity isn't as strong as the Earth’s. That’s why the astronauts who visited the Moon were able to jump really high. If those same astronauts went to a bigger planet, like Jupiter, the gravity would be a lot stronger. There, they would feel much heavier, and they wouldn't be able to jump much at all. People in spaceships are not near anything with a big gravitational force, so they can float in the air inside the spaceship. 

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios