Half The World’s Museum Specimens Are Wrongly Labeled, But Who Is To Blame?

It may sound harsh, but a natural history collection in a museum is almost worthless if it is not properly catalogued. Anyone who has spent even a short amount of time in a natural history collection can attest to the usefulness of well-curated collections. But sometimes, you open a specimen drawer, and immediately recognize a label with an outdated species name. Or even worse, you use the specimen in a study and don’t realize it is labeled wrong. Errors and mistakes like this are not the fault of the museum staff managing these immense collections, or the scientists themselves, but result from combination of factors that coalesce into a big fat mess when the accuracy of collections labels are systematically investigated.

Examples from Royal Botanic Garden Edinburgh's collection (Photo credit: John Baker)
Examples from Royal Botanic Garden Edinburgh’s collection (Photo credit: John Baker)

Researchers at Oxford University and the Royal Botanic Garden Edinburgh examined tropical plants to assess just how many specimens are mislabeled and misidentified in herbaria around the world. In a paper published this week in Current Biology, Zoë Goodwin and colleagues evaluated 4500 specimens of African gingers from 40 herbaria in 21 countries and found at least 58% of the specimens had the wrong names associated with them. But how does this happen?

The authors point to a variety of factors that could lead to the extensive errors in museum collections. For one thing, major taxonomic revisions of groups are frequently needed but rarely completed. It wasn’t until a detailed monograph was done for the group of African gingers that the accuracy of labels could even be assessed. The authors also note with collections growing by leaps and bounds, specifically with the number of specimens in herbaria doubling from 1969-2000, it is impossible to keep up. It is just simply too much for the available experts to handle.

Another interesting problem is specific to the field of botanical collection. Often a single plant is divided into several samples and sent to a variety of herbaria for cataloging. Goodwin found that when the specimens from the same plant were chased down, 29% of them had different names in different herbaria. Simply put, many of these plants look very similar and can be difficult to identify. Again, there is just too much material out there for experts to see and assess to always be accurate in their ID. Although this is a study done with plants, this problem surely extends to all groups studied in natural history museums. Insects, the most abundant and diverse group on Earth, are sure to have considerable problems with accuracy of specimen labeling.

Orchids of Latin America from the Biodiversity Heritage Library (CC BY 2.0)
Orchids of Latin America from the Biodiversity Heritage Library (CC BY 2.0)

In 2004, legendary biologist E.O. Wilson wrote: “There are at present, at rough estimate, ca. 6000 taxonomists at work worldwide on all organisms combined.” Considering there are approximately 1.2 million species currently identified and upwards of 8.7 million predicted to actually exist on Earth, only having <10,000 scientists dedicated to naming millions upon millions of species with accuracy makes the task next to impossible. Although that was 11 years ago, since then there has not been an abundance of resources focused on promoting the field of taxonomy, often viewed as antiquated in the age of big data and rapid full genome sequencing.

Entomologist Quentin D. Wheeler writes in The New Taxonomy: “The taxonomy crisis is to a large extent a funding crisis. Taxonomists have proper techniques for describing and identifying species, but taxonomy as a discipline lacks the necessary funding for accomplishing the task.” A PhD level of expertise is often needed to be a qualified taxonomist, so the amount of money that needs to go into taxonomic training and research is not trivial. And while some think moving to a DNA based identification system is more useful, genetic databases like Genbank are also riddled with errors and mislabeled sequences. As Louisiana State University ichthyologist Prosanta Chakrabarty writes in a 2013 publication, when depositing sequences on Genbank, “The taxonomic determination remains solely the responsibility of the submitter of the sequences.” He goes on to say that once these errors are made, they are hard to discover and even harder to stop from propagating.

Goodwin et al. suggest increased digitization of collections—this way, more experts from around the world can identify specimens more readily without having to travel to collections. They also suggest that DNA analysis should be integrated into taxonomy studies. If these efforts are combined, it is very likely the world’s taxonomy crisis can be better addressed. Nevertheless, the lack of funding for taxonomic research despite its status as a “fundamental discipline” will continue to jeopardize the task of exploring and describing the life on our mysterious planet.

This post originally appeared on forbes.com/science


Analysis Of Ancient Eggshells Reveals Body Temperature Of Dinosaurs

Analysis Of Ancient Eggshells Reveals Body Temperature Of Dinosaurs

When talking about body temperature regulation methods of animals both living and extinct, there is more than just “warm or cold-blooded”. Birds and placental mammals are the stereotypical warm-blooded animals, and reptiles are well-known cold-blooded creatures. But then there animals like echidnas and great white sharks that can modulate their average body temperatures by as much as 50 degrees Fahrenheit, making them something between warm and cold-blooded. And now, a new study in Nature Communications by University of California researcher Rob Eagle and co-authors (including me!) indicates some speciess of dinosaur may have been too.

Scientists use the terms endothermy and ectothermy to refer to the primary methods of body temperature regulation in vertebrates. An endotherm is an organism that generates heat internally to maintain a constant body temperature while an ectotherm relies on external or environmental heat sources. To make matters more complicated, there are organisms that have an intermediate state called “mesothermy”—meaning these animals use internal heat to raise their temperature, but not as high as a typical endotherm.

A life reconstruction of an oviraptorid nest by Doyle Trankina and Gerald Grellet-Tinner. (Image via UCLA)
A life reconstruction of an oviraptorid nest by Doyle Trankina and Gerald Grellet-Tinner. (Image via UCLA)

Modern birds are standard endotherms, but what does this mean for extinct bird relatives like dinosaurs? Obtaining the body temperature of an extinct non-avian dinosaur known only from fossils may seem impossible, but with a new isotope technique, it isn’t at all. The hard shells of both dinosaur and bird eggs are made out of a mineral called calcium carbonate, which is comprised of the elements calcium, carbon, and oxygen.

When digested with acid, carbon dioxide (CO2) is released from the eggshell mineral, and the mass of the CO2 produced is measured with a machine called a mass spectrometer. Specific isotopes of carbon and oxygen produce a certain mass of CO2, and the amount of CO2 with that mass can indicate the temperature of mineral formation. Paleontologists call this method “clumped isotope analysis”. As eggs are formed inside the body of a female dinosaur, the temperature of eggshell calcium carbonate formation should be indicative of the animal’s body temperature.

In this study, the eggshells of two types of dinosaurs were analyzed: oviraptorid theropod dinosaurs from Mongolia and titanosaurid sauropods from Argentina. A wide variety of eggshells from modern birds and reptiles were tested to make sure this method was accurately measuring the body temperatures of these animals.

The “paleothermometer” reading from the clumped isotopes indicates something really interesting—these dinosaurs don’t seem to simply be “warm” or “cold” blooded. While the titanosaurid sauropod had a body temperature similar to a large living endotherm at 100.5 degrees Fahrenheit, the measured body temperature of the oviraptorid dinosaurs from Mongolia were considerably lower. The body temperature of a typical endotherm is at least 100.5 degrees Fahrenheit but the body temperature measured from the oviraptorid eggshell is 95 degrees Fahrenheit. This is lower than most modern mammals and birds. Due to the fact these eggshells were carefully analyzed for alteration and were found to preserve original mineral crystals, this low body temperature is likely an accurate signal. This suggests that these dinosaurs may have not been as warm as typical modern endotherms, but also weren’t completely ectothermic.

Where I collected fossils in Mongolia's Gobi Desert (Photo by Shaena Montanari)
Where I collected fossils in Mongolia’s Gobi Desert (Photo by Shaena Montanari)

I was involved in this paper as I am a paleontologist interested in using geochemistry to examine fossils and traces from dinosaurs—like eggshells. The oviraptors eggshells in this study were samples that I analyzed for environmental signals for my dissertation research. I collected these eggshells during my time doing field work in Mongolia’s Gobi Desert. When I was walking around the Gobi I noticed these pieces of eggshells were everywhere but they weren’t being used for anything—so why not analyze them for isotopes and learn more about the environment of this habitat 80 million years ago?

While my research focused on just carbon and oxygen isotope ratios, I saw these eggshells were also great targets for this clumped isotope body temperature research, so I was fortunate to collaborate with Rob Eagle and other colleagues. Clumped isotopes are a gateway to understanding shifts in modes of vertebrate metabolism in a way we never thought possible before. Now knowing that some dinosaurs had an “intermediate” state of body heat regulation adds a new layer of understanding to the dinosaur-bird evolutionary transition.

Originally posted on forbes.com/science 

Moving Parts

Moving Parts

Being an academic involves constantly uprooting your life and putting on a face to the world like you are totally okay with it. It doesn’t bother you to have to pack up your life every other year, rent a storage unit, leave most of your belongings at your family and friends homes because you LOVE SCIENCE and love what you do. It’s okay when you make amazing friends and then abandon them to go find new ones in far off lands. The truth is, so far I’ve been lucky with my moving. After undergrad, I moved back to NYC and was able to stay there for graduate school and my first postdoc. I am lucky because my family and friends mostly all live in that area of the country. Life was pretty easy and fun in New York.

When this opportunity arose in Edinburgh, I couldn’t turn it down. This fellowship is more prestigious than one I ever dreamed of getting, and if I play my cards right with a lot of luck, I can likely find a more permanent job in the next few years because of it. I got the email that I was in on November 21st and immediately started wrapping up my life in NYC. I was beginning to grow fairly stagnant there, especially staying in the same location after graduate school, I was more than ready for a change. Over the years I’ve avoided moving because I’ve been too afraid to leave, but I finally felt like it was time. Plus, I knew I loved the UK, so it was such an exciting opportunity for me.

So less than two months later, visa in hand, all moved out of NYC, furniture stored in my parents’ garage (they are not happy about this), I was on the plane to Edinburgh. This is an incredible city. I’ve been in my flat for one week today and in the country for about two weeks, and I’ve already had some amazing adventures and met some cool people and been to fun parties. But damn, it’s hard! I’ve always been a very easygoing traveler, staying in other countries for months at a time, rarely missing the USA or my family. Probably because I knew I’d be home soon. This is a different beast. I know I will be home for a visit in 7 months, and only have a two year post here, but I’m really LIVING here. Got a bank account. Got a new phone. Got a flat. Paying taxes, the whole nine yards. Coming home after work to the weird new flat (that doesn’t have internet yet) and the time difference between here and my whole life on the East Coast is just so bizarre to me. As usual, I’m anxious to get it all done. I want to buy all the supplies for my flat. I want to join the yoga studio right now. I want to be immediately productive at work. But it all takes time. People tell me this, I know it, but it is hard to really GET. I came from a really established life and now it is all up in the air. I even get annoyed having to buy all those little things for the apartment that cost mad ££. “I already HAD all of these things!” I think to myself. But I gave them all away to friends in the US and now I need to buy them again.

It doesn’t help when other people in your life don’t understand the academic lifestyle. “You should have just stayed in New York” they say, not fully understanding how important this opportunity is to my growth and my career. I WANT to be here, I love this city, it is amazing and beautiful. I love NYC but I was ready for a change, it was a lifestyle I’m not sure I wanted to keep up forever. But when you hear these negative statements a lot, doubt does creep in. It would have been easier to stay, that’s for sure, but I know deep down it was really time to go.