Biology / Unit 8 Bio 1789 short lesson, about 20 seconds
The Phylogenetic Tree as Hypothesis
Captions available
The idea
A phylogenetic tree is a diagram of hypothesized evolutionary relationships, treated as testable rather than a settled, final record.
In practice
A published tree revised after new DNA evidence contradicts an earlier branch placement shows it functioning as a hypothesis, not a fixed fact.
Where people slip
A phylogenetic tree can change as new evidence arrives — publishing one version does not close off revision.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
Unlocks
Something wrong in this lesson? Flag it · Sources for Biology