Biology / Unit 8 Bio 1795 short lesson, about 20 seconds
Branch Length Does Not Default to Encoding Time
Captions available
The idea
A tree's branches typically show only the order events occurred in, not the time each represents, unless stated otherwise.
In practice
Two branches of different lengths on an unlabeled tree can represent the same time span, since length defaults to ordering, not duration.
Where people slip
Reading branch length as elapsed time is a mistake unless the tree states it is drawn to a time scale.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Unlocks
- Nothing yet depends on this.
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