The following questions refer to the evolutionary tree in Figure 22.4,whose horizontal axis represents time (present time is on the far right)and whose vertical axis represents morphological change.
Figure 22.4
-Which conclusion can be drawn from this evolutionary tree?
A)Gradualistic speciation and speciation involving punctuated equilibrium are mutually exclusive concepts.
B)Eldredge and Gould would deny that the lineages labeled X,Y,and Z could represent true species.
C)Assuming that the tip of each line represents a species,there are five extant (that is,not extinct)species resulting from the earliest common ancestor.
D)A single clade (that is,a group of species that share a common ancestor)can exhibit both gradualism and punctuated equilibrium.

Question

The following questions refer to the evolutionary tree in Figure 22.4,whose horizontal axis represents time (present time is on the far right)and whose vertical axis represents morphological change.
  Figure 22.4
-Which conclusion can be drawn from this evolutionary tree?
A)Gradualistic speciation and speciation involving punctuated equilibrium are mutually exclusive concepts. 
B)Eldredge and Gould would deny that the lineages labeled X,Y,and Z could represent true species. 
C)Assuming that the tip of each line represents a species,there are five extant (that is,not extinct)species resulting from the earliest common ancestor. 
D)A single clade (that is,a group of species that share a common ancestor)can exhibit both gradualism and punctuated equilibrium.

Quizplus · Accepted Answer

A single clade can indeed exhibit both patterns of evolution: gradualism, where species evolve through a slow and steady accumulation of changes, and punctuated equilibrium, where species remain stable for long periods and then undergo rapid changes during short periods, leading to new species. This reflects the complexity and diversity of evolutionary processes.

The Following Questions Refer to the Evolutionary Tree in Figure