Outline of Last LectureOutline of Current LectureCurrent LectureEes 1040 1st Edition Lecture 19Outline of Last LecturePaleozoic FaunaOutline of Current LectureI. Phylogeny II. SpeciationIII. ExtinctionIV. CriteriaCurrent LectureI. Phylogeny A. The evolutionary history of a group of organismII. SpeciationA. The origin of a new species1. Anagenesisa. Start with one species evolves into another through timei. Replacing one species with another2. Cladogenesisa. One species evolves into two separate speciesi. Split3. One species has a divergent speciesi. branchingIII. ExtinctionA. The disappearance of a species via its last surviving members IV. CriteriaA. Similarity/Analogous1. Appearance and physical featuresB. Homology1. The presence in different organism of structures derived from the same structures in the common ancestorC. Homoplasy1. The presence in different organisms of closely similar structures derived from different ancestral structuresa. Ex. Wingsi. Are Wings Homolgous or Homoplastic?- Birds: entire arm (feathers attached to the arm)- Bats: hand (membrane attached to the hand/fingers)- Pterosaur: 4th finger (membrane attached to finger(singular))ii. Wings in bats, pterosaurs, and birds are analogous to each other (similar structure and function) but non homologous- Share analogous function (flight) and shape, but have different evolutionary originsD. We have to distinguish between types of Homologies1. Synapomorphy (shared derived characters)a. Shared, derived homology2. Symplesiomorhphy (shared general)a. Shared, general homology3. Therefore, we need to identify synapomorphies in order to reconstruct
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