Fig. 4.

Classical tree-like representations of genetic structure for the Spanish meadows. (A) UPGMA tree based on Goldstein distances, displaying a quite uninformative comb-like structure. (B) Minimum Spanning Tree (MST) based on Goldstein distance among Spanish meadows. This is the subgraph that connects the populations at the Spanish coast scale minimizing the total genetic distance along links, with the diameter of nodes illustrating their index of betweeness centrality according to the topology of the MST.