Toy example illustrating the construction of the spectral density for a hypothetical phylogeny. Top: example phylogeny. Middle: computation of the MGL. Each non-diagonal element (i, j) in the MGL Λ is equal to the negative of the branch length between nodes i and j. Each diagonal element i is computed as the sum of branch lengths between node i and all other nodes j. Bottom: the spectral density is obtained by convolving the λ calculated from Λ with a smoothing function
