This is a Zoom only event. Please visit the MCAS website for the Zoom link.

UNCOVERING THE EVOLUTIONARY ORIGINS AND DEVELOPMENTAL FOUNDATIONS OF BEAK SHAPE IN THEROPODS USING A UNIVERSAL RULE OF GROWTH, by Kathleen L.S. Garland, Melbourne, Australia

Bird beaks come in almost every shape and size – from the straw-like beak of a hummingbird to the slicing, knife-like beak of an eagle. In her talk, Kate will discuss her PhD research into how, despite this incredible diversity, there is an underpinning mathematical rule that governs the growth and shape of beaks in nearly all living birds. She as also found that this rule even describes beak shape in the long-gone ancestors of birds – the dinosaurs. This mathematical rule, called the power cascade, describes the relationship between the beak radius and the distance from the tip. Kate measured the rostra of 127 bird and other non-avian dinosaur species and found that 95% of them follow the power cascade model of growth.

Among living birds, variation in power-cascade parameters is associated with distinct ecological adaptations, including feeding and foraging. Developmental comparisons across several bird groups show that species whose adult beaks follow the cascade also grow in a predictable way through development (from embryo to adulthood). However, species with specialised elongate beaks (including the royal spoonbill Platalea regia) deviate from the growth pattern in later stages of growth.

Overall, the findings from her PhD demonstrated that, from the developmental to the macroevolutionary level, the power cascade may govern the shape of most theropod rostra.

Kate is a PhD candidate at Monash University, Melbourne. She has a Bachelor of Science from the University of Queensland and a double degree from the Erasmus Mundus Master Programme in Evolutionary Biology. Throughout her education in science, Kate became fascinated by growth processes underpinning the evolution of the diverse morphological adaptations across the tree of life. For her PhD, Kate is studying how one such universal model of growth may determine the evolution of bird beak shape.