DNA adds some 'mussel' to conservation efforts

The Southeastern United States is a center for biodiversity in North America. This is particularly true for freshwater mussels. The Ohio Valley is home to numerous species of freshwater mussels (family: Unionidae; class: Bivalvia) and the upper Coosa River basin in Tennessee, Georgia and Alabama was once home to over 40 species of freshwater mussels making it among the most biologically diverse freshwater habitats on Earth. Unfortunately, however, human activity in the great watersheds of the Southeast have had devastating effects on freshwater mussel diversity. The building of locks and dams, agricultural and industrial run-off and urbanization along rivers have all contributed to the extinction of many species of freshwater mussel. In the Ohio valley species like the Clubshell (Pleurobema clava, see photo left) exist in populations that are considered highly vulnerable to extinction and other species, like the Tubercled Blossum (Epioblasma torulosa, see photo bottom right, both specimens are from the Cincinnati Museum Center Zoology collection), are likely extinct already. For freshwater mollusks in general over 70% of the known species are extinct or in danger of extinction.

Identifying one mussel species from another can however be difficult. Mussels are typically identified on the basis of the size, shape and texture of their shells, however, within populations these traits can vary significantly and often vary in response to variation in the environment. The difficulty in identifying one species from another confounds conservation efforts to identify threatened populations and leaves open the possibility that species thought to be extinct may persist in populations with aberrant characteristics making them difficult to distinguish from more common species.

In a recent paper by University of Alabama researcher David Campbell and his colleagues, DNA barcoding was used as a tool in identifying freshwater mussel species in the Coosa basin. DNA barcoding involves sequencing a segment of DNA common to all organisms. In general, sequences should be unique to a species, although there is often some sequence variation within species as well. DNA barcodes can be used in addition to analysis of morphological characteristics as a tool in identifying species. Focusing on the freshwater mussel genus Pleurobema, DNA barcoding revealed the existence of four species thought to be extinct from the Coosa basin; Pleurobema chattanoogaese, P. hanleyianum, P. troschelianum, and P. stabile. The DNA evidence showed that all of the Coosa basin specimens previously identified as Peurobema perovatum were actually the supposedly extinct P. hanleyianum. Also, the Warrior Pigtoe (Pleurobema rubellum), a mussel species currently listed as extinct, was identified using DNA barcoding from the nearby Black Warrior River system.

This study shows the utility of DNA analyses in conservation efforts. With the growing emphasis on DNA techniques here at Cincinnati Museum Center plans are underway to adopt DNA barcoding protocols on threatened and difficult to identify groups, like freshwater mussels, in the Ohio Valley.

CAMPBELL, D.C., JOHNSON, P.D., WILLIAMS, J.D., RINDSBERG, A.K., SERB, J.M., SMALL, K.K., LYDEARD, C. (2008). Identification of ‘extinct’ freshwater mussel species using DNA barcoding. Molecular Ecology Resources DOI: 10.1111/j.1755-0998.2008.02108.x

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University of Cincinnati Drawing Class

Museum collections have many uses, and not all of these uses for museum specimens are scientific. The zoology collection at Cincinnati Museum Center is often used by local artists to create biologically accurate wildlife art. Field guides are an excellent example of the synergy between art and science in museum collections. Jim Day of Talon Wildlife Creations is one such local artist who regularly uses the collection to create life-like reproductions of birds from domestic bird feathers. Other well known artists such as John Ruthven and the late Charley Harper have used the zoology collection extensively as reference material for their artwork.

The next generation of artists are utilizing the zoology collection as well. Led by instructor Courtney Bennett students from the University of Cincinnati visited the collection in late February (see photo right). The students were sketching everything from mounted Ring-tailed Cats to primate skulls to Harpy Eagle study skins. Courtney recently sent us photos of some of the student work (see photo above left). We hope to host many other local artists, both professional and student, and provide them with many subjects for biological illustration and wildlife art.

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Ecuador: Part I

We just returned from the tropics and the beautiful country of Ecuador. As it's name suggests Ecuador straddles the equator and is one of the most biodiverse countries in the world. For birds alone the tiny nation of Ecuador boasts over 1,600 species, compare that to just over 900 for all of North America north of Mexico. The Northern Andes form the spine of Ecuador running along the middle of the country. To the east is the Amazon basin and to the west the Pacific coast and in Northwestern Ecuador is the Choco, a very biodiverse region with many endemic species, extending from Panama, through Columbia and into Ecuador.

Our trip began in the cloud forests of the Andean slopes of Southeastern Ecuador at the Jocotoco Foundation's Tapichalaca Reserve located in the Podocarpus National Park. Montane cloud forests form in areas where warm air masses cool as they rise in the face of high mountain slopes. Moisture condenses in these rising air masses and blankets the forested slopes in clouds, mist and rain. Cloud forests are some of the wettest environments on Earth and provide the perfect environment for moisture loving plants, especially mosses, bromeliads and orchids (see photo above left). Many of these plants are epiphytes, growing on the trunks and branches of trees (see photo right). Despite being near the equator the elevation of these forests keeps the temperatures comparatively mild year round. Our time at Tapichalaca was during the tail-end of the rainy season and rain fell regularly during our stay making the steep mountain trails a muddy slog through the forest.

The cloud forests of Ecuador are home to many unique animals. The near constant wet conditions provide an ideal habitat for high humidity loving animals such as frogs and land snails. Many bird species are also found exclusively in tropical cloud forests. The recently described Jocotoco Antpitta (Grallaria ridgelyi, see photo left) is a ground bird found only in a small area around the Tapichalaca Reserve. Birds like the Jocotoco Antpitta make the region a Mecca for birdwatchers around the globe. Other cloud forest specialties include the Black-billed Mountain Toucan (Andigena nigrirostris), the Hooded Mountain Tanager (Buthraupis montana) and Collared Inca (Coeligena torquata).

Steep mountain forests in the tropics remain some of of the most well preserved natural ecosystems in the world, however, threats to these seemingly inaccessible habitats remain. Greater awareness through research, conservation and carefully controlled ecotourism can help preserve these unique montane forests. Cincinnati Museum Center plans to organize future trips to Ecuador for area birders and other nature enthusiasts. This trip represents the initial exploratory forays into a new tropical montane biodiversity program. Stay tuned for upcoming reports from our expedition to Ecuador and news on future ecotourism opportunities to visit Ecuador with Cincinnati Museum Center scientists.

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Science and Religion

Listen to an excellent audio essay by Nobel Prize winning physicist Frank Wilczek on the nature of science and religion on the March 13 Nature Podcast. This essay does a good job in cutting to the heart of the current problems in reconciling science, like evolution, and religious faith.

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Browse the inverts

A collection inventory from the Cincinnati Museum Center's Invertebrate Paleontology Department is now available online on the museum's cincyevolution web site. The inventory is a simple listing of the genera contained within the collection. More of the CMC's natural history collection will be available online over the course of the coming year. Enjoy!

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Wing of the Week

Here's a new wing. This week we have the subtle browns and reds of the wing of the Bukidnon Woodcock (Scolopax bukidnonensis, topside of wing in the top photo and wing's bottom side in the bottom photo). This species was first described to science in 2001 by former Cincinnati Museum Center zoology curator Dr. Robert Kennedy (Kennedy et al. 2001 Forktail 17: 1-12). Woodcocks are an unusual group of forest and field dwelling shorebirds with rounded, dome-shaped heads and large eyes positioned on the top of their heads to give them a 360 degree field of vision. Recorded on the islands of Luzon and Mindanao in the Philippines, little is known about this secretive species. Dr. Kennedy first caught a single individual of this species on 22 January 1995 on Mount Kitanglad on the island of Mindanao in the Lanao-Bukidnon Highlands (hence the name given to this species of the Bukidnon Woodcock) and that specimen served as the type by which the species was described. Just another one of the important specimens in the Cincinnati Museum Center's Zoology Department documenting biodiversity on a global scale. For more on the unique avifauna of the Philippines check out Dr. Kennedy and coauthor's book 'A Guide to the Brids of the Philippines'. I'll have more on a relative of the Bukidnon Woodcock that lives in Ohio with the next installment of 'Wing of the Week'.

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A penguin in the hand...

Geoff Hill's visit to Cincinnati Museum Center was a huge success. With great turnout for his lecture in the Charles and Ralph Dury Lecture Series and about 300 showing up at the Amish Bird Symposium in Adams co., OH, lots of folks in the Southern Ohio/Northern Kentucky area got to hear about Geoff's exploration of the Choctawhatchee River and the hunt for Ivory-billed Woodpeckers (Campephilus principalis). I think Geoff had a great time during his trip to Cincinnati, but, I believe a highlight of Geoff's visit was a visit to the Cincinnati Zoo and Botanical Garden. The Cincinnati Zoo's Avian Conservation Program Manager, David Oehler, showed Geoff and I behind the scenes and we were able to get up close and personal with one of the zoo's Rockhopper Penguins (Eudyptes chrysocome, see photo right with Geoff Hill on the left and me on the right and penguin in Geoff's arms). Thanks to David Oehler of the Cincinnati Zoo, Regina Hall and Patrick Nugent of the Cincinnati Museum Center, Chris Bedel and all the organizers and sponsors of the Amish Bird Symposium for hosting Geoff during his stay in Cincinnati.

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Wing of the Week

OK, so this is more like a biweekly wing. In honor of the visit by Auburn University ornithologist Dr. Geoff Hill to the Cincinnati Museum Center this week on Feb. 28 to participate in the museum's Charles and Ralph Dury Lecture Series let's take a look at the wing of a Pileated Woodpecker (Dryocopus pileatus). Putative Ivory-billed Woodpecker (Campephilus principalis) sightings are often in actuality this common species of the woodpecker family. The difference is that on both the topside (top photo) and the bottom (bottom photo) of the Pileated Woodpecker wing there is no white on the trailing edge. Knowing what field marks to look for is absolutely critical for those looking to tick off an Ivory-billed Woodpecker from their life lists!

For those in the Cincinnati area I encourage you to attend the lecture by Dr. Geoff Hill on Feb. 28 at 7:30 at Cincinnati Museum Center to learn more about the hunt for the elusive Ivory-billed Woodpecker. Also, check out Dr. Hill's new book, 'Ivorybill Hunters: Search for Proof in a Flooded Wilderness', on the Ivory-bill Woodpecker search.
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Big Mouth!

Some very special spots on the globe reveal important clues to the history of life on Earth. Madagascar is one of these very special places. The continents are on plates that float on the more viscous lower layers of the Earth. Land masses split apart and collide. Often our geographic boundaries of land masses that are not in accord with their geologic boundaries. For example, what we define as the combined continent of Eurasia is actually comprised of land masses on different geologic plates. India is on a different plate than the rest of Asia and has been colliding with Asia for approximately the past 50 million years. This collision between the India Plate and the Eurasian Plate is pushing up the Himalayas. Prior to it's collision with Eurasia India was part of a single landmass that included Madagascar and the Seychelles.

The geological history of these places is not just reflected in the rocks but also in their plants and animals. For example, a recently discovered species of a palm, Tahina spectabilis, found in Madagascar has it's closest relatives in India. After the combined landmass of India, the Seychelles and Madagascar split from Africa it drifted into what is today Antarctica, which at the time was also connected to South America. This connection via Antarctica explains some odd biogeographic patterns. The large constricting snakes encompass two groups distinguished by their mode of reproduction. Boas are primarily confined to the Americas and give live birth while the pythons, found in Africa and Asia, lay eggs. Most boas are found in the Americas, but, two species of boa, very similar to the boas of Central and South America, are found in Madagascar. The distribution of the boas provides another clue to Madagascar's geological history.

Now, a new find by Susan Evans of University College London and her colleagues provides yet more clues to Madagascar's complex history. The anuran (frogs and toads) sub-family Ceratophrynae contains large predatory frogs found in tropical and subtropical forests in South America. These frogs are large, fat blobs with huge mouths. Often seen in the pet trade they are popularly known as "pac-man frogs" due to their characteristic "all-mouth" morphology (see photo of juvenile Ceratophrys ornata right). Ceratophryine frogs are sit-and-wait predators who sit on the forest floor camouflaged int he leaf litter waiting for large insects, or even small mammals to walk by. It seems that like the Boas the Ceratophryine frogs have, or once had, cousins from Madagascar.

Evan's team discovered a new species of Ceratophryine frog from Madagascar. The new species is described from fossil material from the Mahajanga Basin in northwestern Madagascar. Extant Ceratophryine frogs are very large frogs, but, this new species dwarfs the existing Neotropical species and indeed at 40 cm long and 20 cm wide is larger than the largest known extant frog, the Goliath Frog (Conrauna goliath). Due to it's broad bony head and it's imposing size and likely predatory habits, like those of other Ceratophryines, the researchers named this new species Beelzebufo ampinga, or "shielded devil frog". This imposing fossil dates to the late Cretaceous about 65-70 million years ago.

Beelzebufo ampinga's relationship to the South American Ceratophyines and it's place in Madagascar's history at the late Cretaceous presents a bit of a puzzle. The present day islands of Madagascar, the Seychelles and the sub-continent of India split from Africa as one land mass approximately 160 million years ago and began to divide into their present day land areas about 88 million years ago. Shortly, geologically speaking, after the split from Africa the Madagascar-Seychelles-India land mass was in contact with the Antarctic land mass, which was also connected with both South America and Australia, but, the timing and duration of this contact is debated. The common ancestor of the modern South American Ceratophryines and this new Malagasy Ceratophryine must have inhabited this ancient interconnected Anatarctic-South American-Australian-Indian-Malagasy continent.

However, evidence from genetics provides another puzzle. The genetic data suggest that the modern Ceratophryine group diverged from a common ancestor well after the late Cretaceous. This would mean that Beelzebufo ampinga arose well before the appearance of the Ceratophyrines and isn't a Ceratophryine at all but rather evolved it's "pac-man-like" characteristics independently of the modern Ceratophryine frogs. However, Evans provides some compelling evidence that Beelzebufo ampinga is indeed a member of the Ceratophryine clan which means that the genetic data is misleading or that the history of these southern land masses is not as expected with much later and perhaps longer connections between Madagascar, Antarctica and South America. Beelzebufo ampinga is yet another dramatic example of the complex history of the Earth and surely will help us better understand the drifting continents and the distribution and evolution of plants and animals.

Read more about this finding at the Nature News website and the Proceedings of the National Academy of Sciences.

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Happy Darwin Day!

Today is the 199th anniversary of Charles Darwin's birth. Born on this date in 1809 (coincidentally the same day as Abraham Lincoln) Darwin eventually would revolutionize biology. The idea that life shares a common ancestry and changes over time preceded Darwin, but, until Darwin's theory of natural selection, no one had yet posed a viable mechanism by which evolutionary change occurs. Darwin's deceptively simple idea was based on a few very basic premises; populations vary, their variations can be passed from parent to offspring, and some variants leave more progeny than others. Some individuals leave more progeny than others owing specifically to how their characteristics perform in a given environment relative to other traits in the population. This is natural selection, and it remains a central idea in modern biology explaining everything from the beaks of finches to the spread of antibiotic resistant bacteria.

Darwin's monumental contribution to the life sciences was recognized by the scientific community almost immediately. So important were Darwin's ideas to the advancement of science that he was buried in Westminster Abby near that other of Britain's fathers of modern science, Issac Newton. Placing Darwin's remains in Westminster alongside Newton was a recognition that Darwin's theory of evolutionary change was as important as an accomplishment as Newton's ideas on gravity and optics. Today evolution remains the central organizing principle in the life sciences, a testament to Charles Darwin's scientific genius.

Next year will be the 200th anniversary of Darwin's birth and the 150th anniversary of the publication of the Origin of Species. Next year look forward to exhibits and other activities at Cincinnati Museum Center, and scientific institutions and museums around the globe, celebrating Darwin's scientific accomplishments and the central role of evolution in helping us explain the natural world.

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