Biology / Unit 8 Bio 1671 short lesson, about 20 seconds
Molecular Evidence: DNA Universality
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The idea
All life shares the same DNA-based genetic code, and closely related lineages share more similar DNA sequences than distantly related ones.
In practice
Comparing the same gene's sequence across two species and finding it nearly identical indicates a recent common ancestor.
Where people slip
DNA's universal structure is evidence for one shared ancestor — it is not proof of any single lineage's relationships.
Your place on the trail
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