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It is mandatory to specify the number of reticulation nodes to added to the starting network. The -s option allows the users to specify a starting network (can be a tree) for network search. Then starting from this network, numReticulations number of reticulation nodes will be added during the network search using steepest descent. If the starting network is not specified, the optimal tree under MDC (command infer_ST_MDC) will be used. If it is not binary, a random resolution will be used. By default, only the first optimal species network will be returned. However, users can use -n option to ask for multiple optimal networks.
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