ANT 350 Lecture Notes - Lecture 8: Maxillary Canine, Weight-Bearing, Dryopithecus
Document Summary
Classification: ordering of organisms into taxonomic groups (species, genera, etc) Phylogeny: establishing lineages (biological history), usually in a chronological framework. There are two approaches to classifying and establishing a phylogeny : phenetics: grouping on the basis of overall similarity. Total morphological pattern: cladistics: grouping on the basis of shared derived characteristics only. Plesiomorphs plesiomorphic features ancestral features primitive features. May still be present in living organisms, may not be. Judging polarity whether traits are plesiomorphic or apomorphic. Last common ancestor (lca: go back into the fossil record. Outgroup comparison: find out who has it and who doesn"t. Accurate classifications and phylogenetic reconstructions must be based on homologies. Reflect patterns of ancestry: some homologies are very recent in biological history of related taxa (lineages), others are very ancient, example: australopithecus boisei and homo sapiens. Both have: human maxillary canine form & y-5 molar pattern. Both traits reflect common ancestry and indicate a phylogenetic connection.
