The following questions refer to this phylogenetic tree, depicting the origins of life and of the three domains. Horizontal lines indicate instances of gene or genome transfer.

A possible phylogenetic tree for the three domains of life.
-Which portion of the above figure may ultimately be better depicted as a "ring"?
A)the bacterial lineage
B)the archaean lineage
C)the eukaryotic lineage
D)the trunk of the tree
E)the part corresponding to the first living cell on Earth

Question

The following questions refer to this phylogenetic tree, depicting the origins of life and of the three domains. Horizontal lines indicate instances of gene or genome transfer.
  
A possible phylogenetic tree for the three domains of life.
-Which portion of the above figure may ultimately be better depicted as a "ring"?
A)the bacterial lineage 
B)the archaean lineage 
C)the eukaryotic lineage 
D)the trunk of the tree 
E)the part corresponding to the first living cell on Earth

Quizplus · Accepted Answer

The "trunk" of the phylogenetic tree represents the earliest evolution of life and is characterized by horizontal gene transfer and lack of clear branching between domains. These features make it difficult to depict as a traditional tree and may be better represented as a ring.

The Following Questions Refer to This Phylogenetic Tree, Depicting the Origins