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.

Figure 26.4. A possible phylogenetic tree for the three domains of life.
-Which portion of Figure 26.4 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.
  
Figure 26.4. A possible phylogenetic tree for the three domains of life.
-Which portion of Figure 26.4 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 tree represents the common ancestry of all life, which may be better depicted as a "ring" due to horizontal gene transfer among early life forms, blurring the lines of distinct lineages.

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