The following questions refer to the phylogenetic tree in Figure 20.3, depicting the origins of life and of the three domains. Horizontal lines indicate instances of gene or genome transfer.
Figure 20.3
A possible phylogenetic tree for the three domains of life.
-Which portion of Figure 20.3 may ultimately be better depicted as a "ring"?

Question

The following questions refer to the phylogenetic tree in Figure 20.3, depicting the origins of life and of the three domains. Horizontal lines indicate instances of gene or genome transfer.
  Figure 20.3
A possible phylogenetic tree for the three domains of life.
-Which portion of Figure 20.3 may ultimately be better depicted as a "ring"?

Quizplus · Accepted Answer

The trunk of the tree represents the common ancestry of all life, and recent research suggests that horizontal gene transfer was prevalent among early life forms, making a "ring" a more accurate depiction than a linear tree.

The Following Questions Refer to the Phylogenetic Tree in Figure