The accompanying figure shows data on composite values for beak size,beak shape,and body size for the medium ground finch (Geospiza fortis)inhabiting Daphne Major.Complete data sets were collected from 1973 onward.
For each of the three graphs in the accompanying figure,the 95% confidence intervals are shown as vertical bars extending above and below each data point for each year.The fact that many of these 95% confidence intervals do not overlap with the data from 1973 (the original reference point for this study)do not overlap reveals that ________.
A) no detectable change in these phenotypes was measured
B) no evolution can be documented
C) detectable change in phenotypes was observed, but the changes were not heritable
D) detectable evolution by natural selection did occur
E) None of these is an accurate statement.

Question

The accompanying figure shows data on composite values for beak size,beak shape,and body size for the medium ground finch (Geospiza fortis)inhabiting Daphne Major.Complete data sets were collected from 1973 onward. 
For each of the three graphs in the accompanying figure,the 95% confidence intervals are shown as vertical bars extending above and below each data point for each year.The fact that many of these 95% confidence intervals do not overlap with the data from 1973 (the original reference point for this study)do not overlap reveals that ________.
A) no detectable change in these phenotypes was measured 
B) no evolution can be documented 
C) detectable change in phenotypes was observed, but the changes were not heritable 
D) detectable evolution by natural selection did occur 
E) None of these is an accurate statement.

Quizplus · Accepted Answer

The fact that many of the 95% confidence intervals do not overlap with the data from 1973 indicates that significant changes in the phenotypes of the medium ground finch occurred over time. This suggests that detectable evolution occurred through natural selection. Option A is not correct, as significant changes were observed in the phenotypes. Option B is not correct, as detectable evolution did occur. Option C is not correct, as the changes were heritable, as stated in the passage. Option E is not correct, as the correct answer is D.

The Accompanying Figure Shows Data on Composite Values for Beak