Blogs

Tuesday, March 22, 2016

Lindsay Campbell in Peru

Doctoral student Lindsay Campbell is in Peru, attending the Latinamerican meeting of the American Society for Tropical Medicine and Hygiene, where she will present a talk on landscape influences on rodent communities in the western Amazon. She will also attend a working meeting of a project team for this work with landscape ecology of rodent-borne diseases in the Amazon, which is funded by the Inter-American Institute.

Thursday, January 14, 2016

A Colorful Culture

In additon to the diverse ecology, rich cuisine, and wonderful coffee, Costa Rica is admired for its colorful culture. Diverse gifts, from woven hammocks to handmade ceramics, reflect this. On our way back to San Jose we stopped in Sarchi, a town referred to as Costa Rica’s handicrafts capital. Inside one of the local shops was El Galeron de los Pintores, where several local artists hand-paint intricate designs on a variety of art pieces.

Among the art on display were selections of full-size and miniature oxcarts, or carretas, decorated in an array of bright colors.  These recall traditional oxcarts used in Costa Rica during the 19th century. As the demand and production of coffee grew, carretas became the primary means to hauling goods from plantations. In the early 20th century, people began painting the carts with colorful displays. Since everything is done by hand, no two are exactly alike. Nowadays the carts are reserved for special occasions, such as the Oxcart Drivers Day held annually in Escazu.

The carretas, a national symbol, represent a unique aspect of the history of Costa Rica. The people of Costa Rica live to the motto pura vida, meaning pure life, a simple phrase with a profound meaning. The display of bright colors on arts and crafts perfectly captures the country’s vibrant culture and lifestyle. 

Thursday, February 18, 2016

KU Cryogenic Storage Expands with Biodiversity Collections

Andy Bentley removes specimens from a cryogenic dewar.

 

If you think you are cold this winter, remember others always have it worse. For instance, consider the tissue samples at the KU Biodiversity Institute.

The KU Biodiversity Institute stores thousands of tissue samples from species found around the globe at a frosty -175 degrees Celsius. The specimens are stored in dewars, which are large, vacuum-sealed containers with a pool of liquid nitrogen at the bottom. While -175 degrees is hard to imagine, the newest dewar at KU dips even lower.


“The latest one we’ve acquired runs at -190 degrees Celsius, but otherwise functions much in the same way,” said KU Ichthyology Collections Manager Andy Bentley.

 

To put that in perspective, NASA satellites found locations in east Antarctica reaching temperatures of -135.8 degrees Celsius, or -93.2 degrees Fahrenheit, still almost 60 degrees shy of the dewar’s temperatures. These antarctic locations boast the lowest temperatures found naturally on earth to date. Humans are expected to survive only three minutes in these frozen conditions--not nearly enough time to build a snowman.
 
East Antarctica, warmer than a cryogenic dewar.
 
The extreme temperatures in dewars preserve usable DNA in tissue samples taken from whole specimens. The voucher specimens are often stored in structure-preserving formaldehyde solutions. However, formaldehyde destroys a specimen’s DNA, rendering them useless for further genetic study. Researchers need a way to keep both the DNA and the whole specimen preserved.

 

“We need a way to preserve DNA before the specimens are fixed in formaldehyde,” Bentley said. “So now in the field we take fresh specimens and extract samples of either internal organs or muscle tissue, place them in a tube, and freeze them before sending the rest of the specimen to be preserved.”

 

Tissues preserved in the dewars are in constant demand. Researchers from all over the world review online catalogs of stored specimens and send requests for tissues that could further their research. Upon receiving a request, the specimen is carefully extracted from the dewar and thawed on ice. Once thawed, a tiny piece of tissue is sliced from the sample and shipped in ninety-five percent ethanol.

 

The number and variety of specimens available for research is growing rapidly. The two dewars currently used are quickly filling with tissue samples. Bentley expects the newest dewar to see use before 2017.

 

“There’s new material coming in from the field at a rate of ten percent a year,” Bentley said. “In ichthyology we expect another 1,100 tissues a year, so with that kind of growth across all departments we expect to fill the two current dewars in six to eight months.”

 

When the first two dewars near capacity, the third will be filled with eight-to-ten inches of liquid nitrogen. This level is monitored 24 hours a day to maintain the crucially cold temperatures. Once filled, the third dewar stands ready to support the growing collection.

 

“There is a fairly large portion of material that is unique to our collection,” Bentley said. “The ichthyology collection, we think, is probably one of the largest ichthyology tissue collections in the world, based on taxonomic and geographic scope.”

 

 


 

Monday, January 4, 2016

Yuccan Eat It, If You Wish

While exploring Lankester Botanical Gardens, we came across a Yucca tree. Yucca is a genus in the Asparagaceae family, comprising an estimated 50 species. Yucca is native throughout Central America and in parts of South America. Due to its high adaptability, yuccas are often spotted in diverse climatic and ecological conditions. Its most notable characteristics are the branching blade-like leaves and when in bloom and assortment of white flowers. The assembly of the leaves creates a canal system for water to travel to the roots for storage. Most species also encompass a dense, waxy coating that assists in preventing water loss.  

Yuccas are typically cultivated as garden and even architectural plants. The yucca flower is the national flower of El Salvador and it is often brought to cemeteries. Many parts of the yucca are edible, from the seeds to the flowers. In Costa Rica, for instance, the flowers are cooked with eggs for a traditional dish, especially during Holy Week and Easter. In Native American cultures, the roots of the Yucca elata, also known as the soaptree, are used as a shampooing agent. In other cultures, dried yucca leaves serve as a handy apparatus to start fires. Just as there are a wide variety of species in this genus, there is an equal diversity of uses by different cultures. 

Monday, January 11, 2016

Ecotourism in Costa Rica

Today we had a day of fieldwork capped off with an insightful talk discussing ecotourism as a tool for conservation. It was conducted by the general manager of the University of Georgia-Costa Rica, Fabricio Comacho. He presented with passion, as he is heavily involved with sustainable development in his home country of Costa Rica. Fabricio touched upon how ecotourism in Costa Rica is an integral part of the country’s income. He stressed how sustainable attractions impact the very environment tourists come to see. Water stress, for example, was a key issue that Fabricio said became more problematic than other issues in recent times. As development increases in rural regions of Costa Rica, the demand for water stresses many of the fragile ecosystems surrounding large resorts or hotels, and therefore also stresses the organisms trying to survive in those areas. Fabricio also mentioned other important component of sustainable development, including the creation of biological corridors, and the nationwide switch to renewable sources of energy. Costa Rica currently boasts approximately %90 of its energy as strictly renewable and aims to be %100 carbon independent by 2030. Seeing this level of respect for the natural environment in the people I  met in Costa Rica made me realize what is possible when there is a nation-wide effort in maintaining the health of the environment. From the standpoint of an American living in a much larger and carbon-hungry nation, I felt saddened and more aware of the apparent apathy the U.S. as a whole applies to the concept of environmental sustainability.

Friday, January 1, 2016

Introducing Dr. Caroline Chaboo


Chaboo taking the zany zip-lining plunge in Costa Rica.

In June 2015, I visited Costa Rica with 14 KU undergraduates for the annual field course. The research part, funded by KU’s Office of International Programs, was to examine the arthropod communities of Zingiberales host plants (bananas and ginger are the most familiar examples).  I personally enjoyed the country so much, that I returned with my family for Christmas holidays, spending the week at the spectacular Manuel Antonio National Park in the Pacific coastal town of Quepos. We enjoyed the adventurous personality of Costa Rica, with beaches, hiking, and zip-lining. Then came my eight KU undergraduates for the field course and new adventures in this beautiful country.

Friday, January 22, 2016

Teenage theropod no more!

Tyrannosaurus rex is without a doubt the most famous dinosaur in the world, and one of the lasting questions people have about this amazing dinosaur is what it was like as a teenager before it was full grown. A paper I co-authored with Bruce Rothschild, a former research affiliate with the University of Kansas Biodiversity Institute, now published online in the journal Cretaceous Research addresses this interesting question.

A nearly complete dinosaur skeleton labeled as BMR P2002.4.1, but more affectionately referred to as 'Jane' in honor of the woman who discovered it, has been the center of a decades long dispute over the validity of a dinosaur called Nanotyrannus lancensis. Nanotyrannus was named by a team led by the famous paleontologist Bob Bakker as a 'pygmy tyrannosaur' from the Late Cretaceous of Montana1. Not all dinosaur paleontologists are convinced of this assessment, and many prominent studies have asserted that Nanotyrannus—specifically 'Jane', the original holotype fossil skull at the Cleveland Museum of Natural History, and a handful of other isolated remainsare instead remanants of immature T. rex. In fact, if you visit wikipedia's page for Tyrannosaurus rex, you will find a proudly displayed image of 'Jane' from the Burpee Museum of Natural History. While paleontologists in this debate have focused on the number of teeth in the jaws2, the overall shape and proportion of the skull3, and whether the texture of the bone is more similar to that of adults of immature individuals4, we observed an isolated character on the skeleton of 'Jane' that shed some additional insight on this debate.

A portion of 'Jane's' lower jaw (called the dentary bone) is marked by a deep groove containing numerous small openings. Bruce Rothschild, who is an expert on ancient diseases and has looked at many jaws from theropod dinosaurs, was unaccustomed to seeing such a feature in a tyrannosaur, and thought this groove was possibly a sign of some disease. It turns out that the other specimens of the embattled genus Nanotyrannus also shared this feature, so it likely wasn't evidence of a disease. After examining additional dinosaur fossils, we found out that, in fact, this groove is found on nearly all theropod dinosaurs outside of the tyrannosauroid group (the group more closely related to T. rex than other meat-eaters like Allosaurus, Spinosaurus, and Coelophysis). Among tyrannosaurs, however, we found an opposite trend: only 7 of 18 tyrannosaurs had this feature, and half of those occurences were found in the group of the earliest tyrannosaurs. We further investigated this question by examining known T. rex material, ranging in age from "baby" all the way to full grown adult, and found that none of these fossils showed the groove we found on 'Jane'!

 

Skull of Nanotyrannus ('Jane') with arrow pointing to dentary groove.

 

So what does this mean? It could be that 'Jane' and all the other fossils we call Nanotyrannus really are juvenile T. rex, and they are undergoing a really dramatic bodily transformation during their growth into adults (puberty sure is rough!), but this is unlikely given that none of the undisputed T. rex fossils we investigated have this feature. This groove is a passageway for nerves and blood vessels to move through the bones of the skull, and short of saying that the nerves and veins of the head dramatically changed their placement as the animal grew, if a baby has no groove, a sub-adult has no groove, and a full-grown adult has no groove, one would logically not expect a juvenile to have a groove either. To us (and some of the other scientists arguing in favor of Nanotyrannus), this is evidence that Nanotyrannus is a different dinosaur from T. rex, and they likely preferred different environments and prey even though they lived at the same time.

What does this mean about how Nanotyrannus fits in to the dinosaur family tree? Even though Nanotyrannus has been variously proposed to be a young T. rex or a closely related species, our phylogenetic analysis actually places Nanotyrannus as a close relative of the albertosaurine tyrannosaurs (moderate-sized theropods that lived in what is now Canada). We obtained this result because they are the only group of advanced tyrannosaurs to possesses the groove we studied. This result was interesting, however, because Charles Gilmore, the paleontologist that described the original Nanotyrannus on display at the Cleveland Museum5, thought it was an example of a new species of Gorgosaurus, one of the types of albertosaurines. History seems to have come full circle.

So now what? Well to the fan club of Nanotyrannus, we have some additional evidence that this was in fact a separate dinosaur species. And for now, the hunt is back on for a complete fossil that shows us what the mighty T. rex was like as a teenage terror.

 

References

1. Bakker et al., 1988. Nanotyrannus, a new genus of pygmy tyrannosaur, from the Latest Cretaceous of Montana. Hunteria 1:1-28.

2. Larson, P. 2013. The case for Nanotyrannus. Pp. 14-53 in Parish et al. (eds.), Tyrannosaur Paleobiology. Indiana University Press.

3. Carr, T. 1999. Craniofacial anatomy in Tyrannosauridae (Dinosauria, Coelurosauria). Journal of Vertebrate Paleontology 19:497-520.

4. Currie, P. 2003. Cranial anatomy of tyrannosaurid dinosaurs from the Late Cretaceous of Alberta, Canada. Acta Palaeontologica Polonica 48:191-226.

5. Gilmore, C. 1946. A new carnivorous dinosaur from the Lance Formation of Montana. Smithsonian Miscellaneous Collections 106:1-19.

Wednesday, January 6, 2016

Edith, the Tarantula


Photo credit: Tracey Funk

On a night hike at the University of Georgia field station, I encountered a hairy friend, Edith. Edith is a Costa Rican Orange-Kneed Tarantula (Brachypelma smithi) that has inhabited a miniature triangular cave for the past year. Female tarantulas live up to 20 years, and occupy a cave or burrow where they wait to ambush unsuspecting prey.

Bradley Hiatt, our night hike guide and a resident naturalist, explained that Edith had been sitting on her egg sac for 6 months. Only one baby tarantula could be found beneath Edith’s wooly legs, the rest left the burrow after their first molt. The male tarantulas pursue females, so they have a lower survival rate than the females who wait in their burrows.

Costa Rican Orange-Kneed Tarantulas are omnivorous and will eat anything, from insects to small rodents. Irritating hairs on the tarantula’s body are used for protection and to catch prey. When attacked, a tarantula will flick the hairs off into a cloud of dust and hairs so it can quickly escape. Edith has been attacked and used these flicking hairs; the evidence is the bald spot on her abdomen. If the tarantula is backed into a corner, it will perform a threat display before biting its attacker with its malicious fangs. This tarantula species’ bite is not lethal to humans but you may have a nasty wound or allergic reaction.

Edith is one of many extraordinary creatures I observed in Costa Rica. Seeing Edith in her natural habitat positively impacted my perception of peculiar or misinterpreted organisms. 

Friday, January 8, 2016

No Rain in the Rain Forest

While researching my previous blog A Dry Rainforest? I learned that Costa Rica is having a more extreme dry season than most and is actually experiencing a drought. To the untrained eye (like mine and most tourists) the forest appears fine; the plants are green and the lack of rain is assumed to be due to the dry season. For those familiar with rainforests, however, the signs are everywhere. Plants have fewer new growths than usual, deciduous trees have lost many of their leaves, and there have been many days with no precipitation at all. The cloud forest in Monteverde, normally a place of constant precipitation even in dry seasons, has received no precipitation for the past five days.
The drought has consequences reaching far beyond the rainforest. Hydroelectric dams generate approximately 82% of Costa Rica’s energy. The dropping water levels caused by the drought result in less water pressure to power the dams, reducing their total hydroelectric power. Costa Ricans must compensate by shifting to fossil fuels, hindering their goal to become the world’s first carbon neutral nation by 2021. It is believed that this drought is the result of a severe El Niño – the same weather system bringing floods to southern California – but the effect is exacerbated by recent climate trends. Global climate change has affected the region by increasing the number of completely dry days during the dry season. Since 2011 the area began experiencing over 100 dry days a year. Ironically, Costa Rica’s forced use of more fossil fuels only exacerbates the issue. If they are to achieve carbon neutral status, Costa Ricans (and the entire global population) will need to find a way to avoid regressing towards using fossil fuels.