Updated steps of SC to generate new ARG from current ARG. The same step numbers and case numbers as in the methods section are used here. Step 3 is a new type 1 recombination created on the current ARG. In step 4, the new branch coalesces into an old branch or a branch on current tree. If the new branch coalesces into the current tree, a new ARG has been constructed. If the new branch coalesces into an old branch, then there are two cases, case 5.1 and case 5.2. In case 5.2, a new ARG is generated. In case 5.1, a new branch is generated which could be dealt with in step 4. When a new ARG is generated, it turns into current ARG and a new round begins. For more details, see the Methods section.