A landmark-free method for quantifying biological shape variation

摘要: We implement a landmark-free method for the quantification of shape variation in evolutionary biology. The is referred to as ‘geodesic distance analysis’ (GDA). It represents shapes continuous boundaries that are invariant translation, rotation and uniform scaling. Boundaries represented functions an infinite-dimensional nonlinear space. arc length curve used parameter model shape. angle between tangent vector positive x axis defined function length. In this way, compared using their functions. Shape differences calculated by finding geodesics (or shortest paths) curves on GDA offers environment performance statistics intrinsic space planar curves. becomes especially appropriate when objects study which landmarks cannot be identified with certainty. present applications analysis organismal morphology. © 2011 Linnean Society London, Biological Journal Society, 2011, 104, 217–233.