While transformations to an aquatic lifestyle have been intensely studied in organisms ranging from insects to whales, basic questions remain unanswered for birds: e.g., how many times has 'aquatic flight' been gained and aerial flight lost? A large collaborative team will focus on resolving the controversial evolutionary relationships of wing-propelled diving birds (including new fossils). Phylogenetic comparative methods will be used to investigate musculoskeletal, neurosensory, and feather microstructure changes across aerial to aquatic flight transitions. Techniques such as X-ray computed tomography, histology, and computer modeling will also be utilized.
Broader impacts focus on interdisciplinary undergraduate, graduate and postdoctoral training in systematics, histology and biomechanics. Highlights include a mentored research experience for undergraduate students from under-represented groups. Public outreach and education activities include co-instruction of a 3 year Geoscience module of the nationally-recognized 'UTeach' secondary school teacher preparation program, 'Expanding Your Horizons' workshops to encourage young women to pursue science careers, web-cast lectures and distribution of curricular materials via university and museum programs, and a dedicated blog. Broad dissemination of research findings is achieved through peer-reviewed publications, conference presentations, and data sharing via online databases.
Penguins have undergone a dramatic transition to adapt to a secondarily marine lifestyle. The goals of this project were to reconstruct the evolutionary relationships of the living and fossil species of wing-propelled diving birds such as penguins, auks, and the extinct plotopterids, and to investigate the changes in the skeleton, brain, feathers, and vascular systems that are associated with adaptation to underwater "flight" in these birds. These goals were met, resulting in several discoveries important to our understanding of diving bird evolution and long-term patterns in diversification and extinction. An evolutionary tree of penguins and related birds was constructed using a large dataset including both morphological characters and DNA sequences. Extinct species were studied from fossils, allowing our team to estimate the dates for many key events in the natural history of diving birds. In addition to studying existing fossil material, new fossils were collected and prepared in New Zealand, including a skeleton of an extinct giant penguin species. Patterns of geographic dispersal were uncovered. Analyses revealed that penguins colonized Africa at least three separate times, arriving from South America. Research on penguin anatomical evolution revealed new patterns in the adaptation of these birds to underwater environments. Studies of the penguin flipper revealed that a key countercurrent heat exchange system evolved at least 49 million years ago, before the time when permanent ice sheets formed in Antarctica. This thermoregulatory structure was thus already in place before penguins began inhabiting extreme polar environments. Virtual models of the brain were created for living and fossil birds, revealing that key changes in neuroanatomy took place both during the evolutionary shift to a diving lifestyle and after the shift to flightlessness. Study of the only known fossil feathers of a penguin revealed unexpected gray and reddish brown color patterns in an extinct species from Peru. Research supported by this award resulted in 11 peer-reviewed papers and 1 book chapter, several popular articles for science magazines, and 10 conference presentations. Datasets collected during the project, including computed tomography (CT) scan reconstructions, microscope image libraries, and phylogenetic data matrices were made freely available to the public and to other scientists via platforms such as Digimorph, MorphoBank and Dryad. These datasets will continue to facilitate research by the project team and other researchers. Collaborations with scientists in New Zealand, Peru, and South Africa strengthened international research ties. This award supported mentored research experiences for seven undergraduate students, most spanning multiple years. These students attained expertise in research skills including computed tomography (CT) data processing and preparation of bone histology sections, gained experience in technical writing, and learned how to properly record, interpret and report scientific data. Four students presented their results at professional science conferences and two subsequently entered graduate programs in the biological sciences. One graduate student also participated in project research resulting in two presentations and two papers. Broader impacts in outreach and education included more than twenty live talks detailing project science at venues including Science Café events, the North Carolina Museum of Natural Sciences, the Carnegie Museum of Natural History, the NCSU Fabulous Faculty public lecture series, a retirement community, and local schools. Data and results from the project were also incorporated into lesson plans for undergraduate and graduate level courses at North Carolina State University. Presentations featuring classroom exercises were given at the NC Science Teachers Professional Development Institute and the Evolution 2013 workshop for teachers organized by the Nature Research Center and NESCent. Replicas of penguin fossils were showcased at the North Carolina Museum of Natural Sciences Fossil Fair event and a video showcasing project research on African penguins was displayed at the NCSU Hunt Library Immersion Theater. Online science content created in this project include the blog March of the Fossil Penguins, which received more than 150,000 visits and podcasts through Critical Wit, Sigma Xi and RTP180.
