Table 2.

Descriptions and prevalence of misconceptions (based on subset of pretest questions)

Misconception	Description	Percent of population exhibiting this misconception (n = 410)
M1: Incorrect Mapping of Time	Confusion about spatial representation of the flow of time on an evolutionary tree.	31%
M2: Tip Proximity Indicates Relationship	Assumption that species that were drawn closer together at the tips of the tree were more closely related to each other than those drawn farther apart.	24%
M3: Node Counting	Assumption that the number of nodes crossed in tracing a path between two species on a tree indicated how closely related they were.	38%
M4: Straight Line Equals No Change	Interpretation that species at the top of a ″straight line″ (i.e., one lineage as straight line extending from common ancestor deep into the tree to one of the tips, with another species branching off) is the common ancestor.	40%