A potential source of confusion in constructing a phylogeny tree is similarity between organisms that is due to:.

 convergent evolution - called analogy

a potential source of confusion in constructing a phylogeny is similarity between organisms that is due to convergent evolution - called analogy - rather than to shared ancestry. thus for mammals, the backbone is a shared ancestral character, a character that originated in an ancestor of the taxon

it would be heredity

a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.