Answer:
UPGMA or Unweighted pair group method with arthematic mean. UPGMA is the simplest method for constructing evolutionary trees. The great disadvantage of UPGMA that all lineages will evolve from the same speed similarly in the molecular clock principle tells that proteins and DNA sequences get evolves at a constant rate over time. this is the This is called a 'molecular clock hypothesis'.
Clustering methods generally use bottom-up clustering methods by both molecular clock and UPGMA or Unweighted pair group method with arthematic mean. It uses the clustering method by connecting similar sequences and further large distant sequences.
These similarities lead to some errors in the relationship.
1. generate wrong tree topologies in both frequently.
2. Re-rooting may not possible and many more.