The figure below shows the increasing morphological complexity in crustacean legs in 12 different phylogenetic comparisons.Why did the authors of this study choose to analyze the data independently for each comparison?
A)The lower sample size in each comparison makes for a more powerful statistical test.
B)This methods allows testing for species selection within each of the 12 comparisons.
C)The observed pattern allows the exclusion of species selection as a possible evolutionary mechanism.
D)This method controls for phylogenetic correlations.

Question

The figure below shows the increasing morphological complexity in crustacean legs in 12 different phylogenetic comparisons.Why did the authors of this study choose to analyze the data independently for each comparison? 
A)The lower sample size in each comparison makes for a more powerful statistical test. 
B)This methods allows testing for species selection within each of the 12 comparisons. 
C)The observed pattern allows the exclusion of species selection as a possible evolutionary mechanism. 
D)This method controls for phylogenetic correlations.

Quizplus · Accepted Answer

The authors of the study chose to analyze the data independently for each comparison in order to control for phylogenetic correlations. This means that they wanted to account for the fact that species within each comparison are likely to be more closely related to each other than to species in other comparisons. By analyzing the data independently for each comparison, they were able to avoid bias due to these correlations and get a better understanding of the patterns of morphological complexity in crustacean legs. Option A is incorrect because a larger sample size generally leads to more powerful statistical tests. Option B is incorrect because the authors did not mention testing for species selection within each comparison. Option C is incorrect because the observed pattern in the data does not necessarily exclude species selection as a possible evolutionary mechanism.

The Figure Below Shows the Increasing Morphological Complexity in Crustacean