tag:blogger.com,1999:blog-8697616560977719586.post4271278428280050621..comments2023-10-28T01:53:23.721-07:00Comments on Systematics and Biogeography: Systematics and Biogeography: Cladistics and Vicariance Online!Malte C. Ebachhttp://www.blogger.com/profile/11901602320985626811noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-8697616560977719586.post-14595512262838427842009-09-17T20:59:56.360-07:002009-09-17T20:59:56.360-07:00I can't see why cladists (remember this term w...I can't see why cladists (remember this term was first used by Ernst Mayr to distinguish them from other schools) consider themselves "revolutionaries". Cladistics is only efficient when one is dealing with morphology, and this kind of information is so terribly biased by subjectivity, that it should never be used as phylogenetic inferential data.<br /><br />Molecular data, on the other hand, is much less biased (bias comes from sequencing errors, lateral gene transfers and poorly chosen alignment parameters) and should reflect the correct evolutionary relationships if correctly analyzed. With the advance of genetic barcoding, the Cladistic methods has become obsolete.<br /><br />Morphology can be interpreted in many ways by different authors, and given the infinity of manners the same information can be scored, it becomes not much more than an exercise of subjectivity.<br /><br />Cladistics is traditionally viewed by serious molecular biologists as a sectarian (almost a religious cult / secret society!) branch of evolutionary research that claims to possess the most efficient and and best logic to propose hypotheses on organismal relationships. <br /><br />Unfortunately, this is not true. Cladists are often narrow-minded and do not accept their "parsimony" method is much more prone to LBA artifact than those usually referred to as "Phenetics", such as Neighbor-Joining and Maximum-Likelihood. This last is the pinnacle of evolutionary inference, since it uses both raw nucleotide data AND genetic distance in its calculations, thus using all data explanatory power.<br /><br />Hence, considering the high subjectivity implied in morphologic matrices, the risk of LBA bias, and the suboptimal use of data explanatory power, Cladistics should be avoided.<br /><br />This makes Phenetics, and not Cladistics, the actual revolution!Larsnoreply@blogger.com