Question

In a phylogeny, when evolutionary histories are not well resolved and the node has multiple (more than two) branches arising from it, this is known as:

1) triploidy
2) polytomy
3) monophyletic groups
4) autapomorphies

Answer 1

In phylogeny, a polytomy is a branch on a phylogenetic tree with more than two lineages, indicating unresolved evolutionary relationships.

Step-by-step explanation:

In phylogeny, a branch with more than two lineages is known as a polytomy. A polytomy occurs on a phylogenetic tree and illustrates where scientists have not definitively determined all of the evolutionary relationships. This situation contrasts with a branch point where speciation results in only two distinct lineages, often referred to as sister taxa. Thus, the correct answer to the student's question is option 2, polytomy.