Gishlick here is using "homologous features" in the sense of a "shared derived character," as discussed above. There are several important points that bear emphasizing. First, biologists do not look at only one line of evidence to infer common descent; it is the agreement of multiple lines of evidence about morphological, genetic, behavioral, ecological and developmental similarity which allows that inference. Second, that inference is a testable hypothesis. The addition of new lines of evidence allows a test of evolutionary hypotheses. For instance, biologists will test evolutionary hypotheses produced based on skull morphology with information from the DNA sequence of a particular gene. A common test for the accuracy of an evolutionary inference is to run the same analysis while excluding part of the data, and using those excluded data to confirm the accuracy of the results. Third, the hypothesis of homology (which follows from an evolutionary hypothesis) is testable. In reconstructions of the common ancestry of a group, it is not uncommon to find that certain
This is the end of the preview. Sign up
access the rest of the document.
This note was uploaded on 11/08/2011 for the course BIOLOGY BSC1086L taught by Professor Leostouder during the Fall '10 term at Broward College.