Squirreling in the Pacific Northwest

You may have heard that researchers discovered a new species of flying squirrel. These squirrels had lived in plain sight for decades but only recently did Brian Arbogast and colleagues investigate the DNA of some of these animals. Their findings were revealing: The Pacific squirrels cluster separately from the northern and southern flying squirrel. The researchers analyzed mitochondrial DNA as well as microsatellite data to reveal this new evolutionary relationship.

Note: Mitochondrial DNA and microsatellites are parts of a species’ genome that are regularly used to construct evolutionary trees. In addition to the DNA in every cell’s nucleus in our body, mitochondria, the energy powerhouses in our cells, have their own genome. This mitochondrial genome is relatively small, is inherited from the mother only and has relatively high mutation rates. It is like a small clonal lineage within an organism which makes it ideal for evolutionary studies.   Microsatellites are short sequence repeats in the nuclear genome that do not produce proteins. Thus they are free to mutate at a higher rate than coding sequences – mutations will not mess up protein production- and they frequently vary in length and thus reveal relationships among organisms. 

A few weeks ago, before this study was published, 2 species of flying squirrels were considered to exist in North America, the northern and the southern flying squirrel. Here in Ohio the northern flying squirrels is resident – it is nocturnal though, that’s why you probably have not seen one yet.

Map showing distribution of now 3 species of flying squirrels

Map showing distribution of now 3 species of flying squirrels

DNA analysis showed that the coastal squirrels in Washington and Oregon are distinct from their northerly relatives and that they actually only co-occur with them at 3 sites in the Pacific Northwest. Northern and the newly described Humboldt’s flying squirrel do not interbreed at these sites. By the way, the researchers named the new species Glaucomys oregonensis because the specimen that was used to describe the species was collected in Oregon.

You may recall from a previous post, that Dr. Andreas Chavez in our department of EEOB studies relationships among squirrels in a different genus, Tamiasciurus, the red squirrel T. hudsonicus and the Douglas squirrel T. douglasii. These two species share habitat in the Pacific Northwest and they do hybridize.

Dr. Chavez was not available for an interview for his thoughts on the new species description of flying squirrels, because he is currently pursuing his own fieldwork in the Pacific Northwest. He and his field assistant Stephanie Malinich are collecting data to better understand the hybrid zone dynamics between the Douglas and red squirrel.

We will give you an update on Dr. Chavez’ research once he returns.

About the Author: Angelika Nelson is the curator of the Borror Laboratory of Bioacoustics and writing this post for Stephanie Malinich, collection manager of the tetrapods collection. Stephanie is currently doing fieldwork on the red and the Douglas squirrel in the Pacific Northwest.

Why describing new species is exciting and important!

For many researchers describing a new species seems like a tedious task. The differences between species might not be obvious, and the language confusing and foreign. This fact became apparent to me when I first presented my work to the Ant Lab at the Museum of Biological Diversity (MBD). As I described subtle differences in morphology, a little spine here and the shape of a hair there, I could tell that I had lost my audience by the dulled looks on my lab mates faces. How could they not see the differences in these two species?

comparison of Trachymyrmex new species and T. zeteki

Fig. 1 – Trachymyrmex new species on the left and T. zeteki on the right

“Some key differentiating characters: The integument is granulose, spatulate bi-colored setae occur between the frontal carina, the scape extends past the occipital corners. This is compared to a weakly irrorate integument, simple bi-colored setae between the frontal carina, and the scape reaching the occipital corners.”

Fig. 2 – In case you are not familiar with the some terms used in describing ant species


Totally clear, right?

While the differences in characters that separate Trachymyrmex new species and T. zeteki, are exciting for me, it seems to bore people to death. After my presentation, I received very helpful constructive criticism from my lab group. They thought it was interesting but a lot of my presentation went over their heads. My advisor, Dr. Rachelle Adams (Assistant Professor in the Department of Evolution, Ecology and Organismal Biology), encouraged me to find a way to turn the jargon into something people can digest and appreciate. I am still working on that, and it is a challenge many researchers face.

Species descriptions are important and a necessary part of daily life

Hopefully your parents told you when you were younger, never eat mushrooms you find in the woods. Taxonomy helps us understand what kind of mushroom you found, if it is edible, or if it might seriously hurt you if you eat it. Mushrooms are a great example of why taxonomy is important. Scientists need to describe and name species so that others can learn which characteristics define a species. Then chemists can tell us which are toxic. This information communicated to the public can potentially save lives! Taxonomists donate representations of species in museums so that they can be compared by other scientists in the future. Aside from publishing their species description, they submit the specimen used to describe the new species, a type specimen. Anyone who works with any type of animal or plant should be submitting voucher specimens, physical specimens that serve as a basis of study, as representatives of their work.

Cody working at microscope

Fig. 2 – Photo courtesy of Plain Janell Photography

My Taxonomic Conundrum

While working on my species description, I reviewed all the literature that included T. zeteki. The 30 papers covered a number of areas such as fungus-growing ant genomes, mating systems, alarm pheromones, larvae development, and gut bacteria. Sadly, almost half of the papers do not mention depositing voucher specimens! Two articles deposited their DNA sequences as vouchers to a database for molecular data. Any research that uses DNA sequences has to submit DNA vouchers to that database; without it your work cannot get published. However, they do not have any physical vouchers linked to their sequences! This lack of physical vouchers was quite a surprise to me. The time I spent as an intern at the MBD Triplehorn Insect Collection, my advisors and other mentors strongly advocated the deposition of vouchers. Without being able to link your DNA sequence to a correctly identified organism, that DNA voucher loses its value. You cannot quickly identify an organism from DNA. Using morphology is the easiest way to do so! It seems many researchers don’t recognize the importance of vouchering and most non-taxonomic journals do not demand it. Research published without vouchers lacks reproducibility, an essential component of the scientific method.

In my research project, I am cleaning up the mess left behind from nearly twenty-years’ worth of poor vouchering and misidentification. I’m not only describing a new species and key characters that differentiate two cryptic species, I am listing all of the papers that have been published in the past twenty years using the names Trachymyrmex zeteki and Trachymyrmex cf. zeteki. By linking the new species description to these articles scientists can move forward knowing the proper identification of these hard-to-identify fungus-growing ants.

The deposition of vouchers should be required for all publications, and is crucial for, past, present, and future research in biology. In my undergraduate research, I discovered there is a disconnect between research museums like the MBD and many scientists. While I am still struggling to turn the technical jargon into information that can be swallowed by non-experts, there are discussions to be had about the importance of taxonomy as a cornerstone in biology.

If you want to learn more about fungus-growing ants and the importance of university research collections, come see us at the MBD Open House April 22, 10am – 4pm.

CodyCardenas, undergraduate student ant lab, EEOBAbout the Author: Cody R. Cardenas is a Senior Undergraduate student in Entomology  working in the Adams Ant Lab.

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The pigeon family

Earlier this week we talked about the role museums play in bringing back extinct species, like the Passenger Pigeon. But how did the Passenger Pigeon get to be part of the pigeon family?

The word pigeon tends to evoke a vision of a motley looking gray-brown plump bird bobbing around a feeder. And while some pigeons can be rather dull looking by exploring the tetrapod collection’s trays of Columbidae, the family for pigeons, you will see that some species are brightly colored, some are big or small, and some have unique feather patterns. Look for why all these different species are put in the same family. Keep an eye out for bill size and shape, which helps define the diet of a species. Examine the overall body shape of the pigeons, this can inform you how they nest, fly or move on the ground. Last, inspect the feet of the pigeons, feet can inform you about diet and movement of a species.

Comment below if you find other characteristics that these specimens have in common and allow us to place them in the same family!

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About the author: Stephanie Malinich is the collection manager of the OSU tetrapods at the Museum of Biological Diversity.

Going where the wasps are.

 

On the previous post we talked a bit about visits to the Museum of Biological Diversity and more specifically to the Triplehorn Insect Collection. Today I want to turn around and show you what we see & do when we put our ‘research scientist‘ hats and go visit other collections.

There’s no walk-ins when it comes to visiting research collections. Setting up an appointment with the curator or collection manager is a must. That allows the staff to prepare for our visit, to set up work stations for us, to review the material we are interested in, and to do curatorial work ahead of our visit if necessary.

Collections welcome research visitors because that fulfill their mission of providing service to the scientific community. In return, visiting scientists add value to the collection by providing expert identification to specimens in the collection, and many times helping out with curation and organization of the collection.

When we get to a museum or collection, the first thing we see is, of course, the door. While most public museums have imposing entrances, many times the access to very important research collections is a modest door on the side of a building. The size and type of door absolutely does not reflect the quality of the collections inside.


Once inside, we have access to the inner sanctum of the collections: rows of cabinets filled with drawers filled with dry specimens carefully separated by group; vaults containing insect specimens preserved in ethanol, waiting to be sorted to family, genus, species. And that’s when our work begins!


During a research visit we usually: 1) examine (lots and lots of) specimens, dry or wet, under the microscope, 2) add identification labels to specimens that we recognize, 3) database the specimen label data, and 4) take photos of specimens (and specimen labels). Sometimes we do only 1 and 2, other times we do mostly 3 and 4. It depends on the collection and what we are hoping to accomplish during our visit.


Over the years we had the opportunity to visit many (many!) amazing research collections in various countries. Besides the collections, their rich treasure of specimens, and their dedicated curatorial staff, we also learnt a lot about the places and the people who live there. Looking forward to our next research visit to a collection!

 

About the Author: Dr. Luciana Musetti is an entomologist and Curator of the C. A. Triplehorn Insect Collection.