A core theme uniting my research is understanding the diversity of life on Earth. I have explored this in deep time, researching ecosystem turnover in dinosaur ecosystems, as well as in the present, studying the evolution of plumage colors in birds.
Structural color
Some of the most vibrant colors in nature, such as the metallic blue of a peacock, are built with microscopic structures that interact with light to produce color. I study the evolution of structural colors in feathers, using a combination of optics, sensory ecology and evolutionary biology.
Science communication
I am passionate about science communication, and have talked about my research to a broad range of audiences. I also produce a podcast about the science of natural history collections, and am active in science outreach and education initiatives at my university and at nearby museums.
About me
I am an experienced researcher with expertise across three fields intersecting biodiversity - evolutionary biology, ecology, and paleontology. I have managed and funded several research projects from start to finish, built interdisciplinary and international collaborations, and developed strong skills in data collection, analysis and presentation. As an interdisciplinary scientist, I am particularly good at distilling complex problems into key insights and communicating it effectively to a broad range of audiences and stakeholders.
Klara Nordén
Publications
A sample of my most recent work
Evolution of brilliant iridescent feather nanostructures
Historical Contingency and Developmental Constraints in Avian Coloration
Melanosome diversity and convergence in the evolution of iridescent avian feathers
Evolution of brilliant iridescent feather nanostructures
The key to vibrant colors lie in the nanoscale details
The brilliant iridescent plumage of birds creates some of the most stunning color displays known in the natural world. Iridescent plumage colors are produced by nanostructures in feathers and have evolved in diverse birds. The building blocks of these structures—melanosomes (melanin-filled organelles)—come in a variety of forms, yet how these different forms contribute to color production across birds remains unclear. Here, we leverage evolutionary analyses, optical simulations, and reflectance spectrophotometry to uncover general principles that govern the production of brilliant iridescence. We find that a key feature that unites all melanosome forms in brilliant iridescent structures is thin melanin layers. Birds have achieved this in multiple ways: by decreasing the size of the melanosome directly, by hollowing out the interior, or by flattening the melanosome into a platelet. The evolution of thin melanin layers unlocks color-producing possibilities, more than doubling the range of colors that can be produced with a thick melanin layer and simultaneously increasing brightness. We discuss the implications of these findings for the evolution of iridescent structures in birds and propose two evolutionary paths to brilliant iridescence.
Historical Contingency and Developmental Constraints in Avian Coloration
To understand color variation in nature, we must pay close attention to evolutionary history
The remarkable diversity of color in nature remains largely unexplained. Recent studies on birds show how historical reconstructions, the identification of genes affecting color differences, and an increased understanding of the underlying developmental mechanisms are helping to explain why species are the color they are. In this paper, we draw on two recent examples - a hybrid manakin species and the genetics of carotenoid coloration - to highlight the importance of historical contingency in color evolution.
Melanosome diversity and convergence in the evolution of iridescent avian feathers
Reconstructing colors of the past
Some of the most varied colors in the natural world are created by iridescent nanostructures in bird feathers, formed by layers of melanin-containing melanosomes. The morphology of melanosomes in iridescent feathers is known to vary, but the extent of this diversity, and when it evolved, is unknown. We use scanning electron microscopy to quantify the diversity of melanosome morphology in iridescent feathers from 97 extant bird species, covering 11 orders. In addition, we assess melanosome morphology in two Eocene birds, which are the stem lineages of groups that respectively exhibit hollow and flat melanosomes today. We find that iridescent feathers contain the most varied melanosome morphologies of all types of bird coloration sampled to date. Using our extended dataset, we predict iridescence in an early Eocene trogon (cf. Primotrogon) but not in the early Eocene swift Scaniacypselus, and neither exhibit the derived melanosome morphologies seen in their modern relatives. Our findings confirm that iridescence is a labile trait that has evolved convergently in several lineages extending down to paravian theropods. The dataset provides a framework to detect iridescence with more confidence in fossil taxa based on melanosome morphology.
