Which of the following is true of all horizontally oriented phylogenetic trees,in which time advances to the right?
A)Each branch point represents a point in absolute time.
B)Organisms represented at the base of such trees are descendants of those represented at higher levels.
C)The fewer branch points that occur between two taxa,the more divergent their DNA sequences should be.
D)The common ancestor represented by the rightmost branch point existed more recently in time than the common ancestors represented at branch points located to the left.

Question

Quizplus · Accepted Answer

In horizontally oriented phylogenetic trees, time advances to the right. Therefore, the common ancestors represented by the rightmost branch point existed more recently in time than the common ancestors represented at branch points located to the left. Thus, option D is correct. Option A is incorrect because not all phylogenetic trees may represent timepoints; some may represent evolutionary relationships. Option B may be true for some trees, but not necessarily for all horizontally oriented trees. Option C is not a generalization that holds true for all trees; the number of branch points could be affected by factors such as incomplete sampling, horizontal gene transfer, and convergence.

Which of the Following Is True of All Horizontally Oriented