Each of the following graphs shows a hypothetical relationsh

Each of the following graphs shows a hypothetical relationship between the predicted order of trait appearance based on trait nesting (y-axis) and the actual order of appearance in the fossil record (x axis) for a number of traits among a group of species. Which graph would provide the best evidence that these species arose by descent with modification from common ancestor? Below are three different hypothetical scenarios of fish species occurrences in the fossil record, with the oldest ancestral species on the left and the more recent descendent species on the right. Traits such as spines and coloration are different in different species. Given what you\'ve learned about evolution in this lab \"these species have arisen by descent with modification from a ancestor, which a scenarios plausible?

Solution

7. The graph 3 with scattered dots allover describe that the species have descended with a modification from common ancestor. The scattered dots appear like branches of tree having a single dot at the base. Option 3 is correct.

[note: 1   2

         *3   4]

8. In the given 3 fish species, ancestor species on left side and recent descendent is on right side. Basing on the given hypothetical fish species, scenarios A is plausible because normal ancestral fish species have developed into fish with spines in the recent descendent.