The value of the fossil record in giving a clear account of evolutionary history has been questioned because of its incompleteness. New evidence suggests, however, that this is not an overwhelming problem: a good match exists between sequences of lineage divergence as indicated by phylogenetic analysis (cladistic hypotheses of relation) and the order of appearance of groups in geologic time for 41 of 74 test-case cladograms of vertebrates. The relative completeness (ratio of known record to gap) of these test cases is highly variable, but there has been a clear improvement in paleontological knowledge (i.e., filling of the cladistically predicted gaps) over the past 25 years.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not have access to this content, please speak to your institutional administrator if you feel you should have access.