Biology / Unit 8 Bio 1801 short lesson, about 20 seconds
Homology and Analogy, Applied to Phylogenetics
Captions available
The idea
Building an accurate phylogeny depends on sorting homologous traits, per Bio 1659, from analogous ones, per Bio 1663, since only homology signals shared ancestry.
In practice
Grouping bats and birds by wing shape alone would wrongly imply close ancestry, since flight evolved independently, or analogously, in each.
Where people slip
Mistaking an analogous trait for a homologous one produces a phylogeny that misreports which lineages share ancestry.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
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