Question

When analyzing relationships among a particular group of taxa, how does a biologist decide which trees are the most parsimonious?

A. The most parsimonious tree always arranges species from simpler to more complex over time.
B. The most parsimonious tree produces the observed traits in the organisms with the lowest number of evolutionary changes.
C. The most parsimonious tree has the fewest number of branch tips (twigs) on it.
D. The most parsimonious tree can be found by matching the phylogeny to known evolutionary trends.

Answer 1

The most parsimonious tree is identified by finding the simplest evolutionary pathway with the least number of changes required to produce the observed traits, not by the arrangement of species complexity or branch tip count.

Step-by-step explanation:

When analyzing relationships among a particular group of taxa, a biologist decides which trees are the most parsimonious by assessing the tree that produces the observed traits in the organisms with the lowest number of evolutionary changes. The most parsimonious tree does not necessarily arrange species from simpler to more complex over time, nor does it have the fewest number of branch tips. Instead, it is found by looking for the simplest evolutionary pathways that involve the fewest major events or changes that coincide with the evidence at hand, and it often aligns with the organisms that share the most traits in common.