Practice question · Multiple choice
Early phylogenies assumed inheritance was strictly vertical, yet horizontal gene transfer is pervasive among prokaryotes. What does this distinction imply for reconstructing the earliest evolutionary relationships?
Hints
- What happens when you build a phylogenetic tree using a gene acquired from an unrelated neighbour?
- Does the sharing of individual genes erase deep structural differences in transcription and membrane chemistry?
Show the answer
B. Gene trees for different loci will frequently conflict rather than trace one trunk
Why
Because horizontal gene transfer moves sequences between unrelated contemporary lineages, different genes tell divergent evolutionary histories. This yields a reticulated web rather than a simple bifurcating tree, though fundamental domain biochemistry remains distinct.
Practise The First Cells and Endosymbiosis
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More questions on The First Cells and Endosymbiosis
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- Match each piece of evidence for endosymbiosis to what it indicates.
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- Complete the account of how genes move between prokaryotes.
- Arrange these events in the order they occurred in the history of life.