Figure 6From: MUSCLE: a multiple sequence alignment method with reduced time and space complexityNeighbor-joining and UPGMA trees for progressive alignment. Here we show the same set of four sequences and the order in which they will be aligned according to a neighbor-joining tree (above) and a UPGMA tree (below). Notice that t and u are the most closely related pair, but (s, t) and (u, v) are evolutionary neighbors. With neighbor joining, t and u are not aligned to each other until the root, in contrast to UPGMA, which aligns s and t as the first pair.Back to article page