BIOL 1105 Lecture Notes - Lecture 11: Cladistics, Reptile, Polyphyly
12 Dec 2017
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Document Summary
If fossil records were perfect it will be easy to trace back the ancestors and evolutionary relationships. How do we study evolutionary relationships: systematics- the reconstruction and study of evolutionary relationships, systematists construct evolutionary trees phylogenies to present hypotheses about relationship among species. Branching diagrams depict evolutionary relationships: charles darwin illustrated the idea of species descending from a common ancestor with a branching tree diagram. Phylogenies are hypotheses based on the data: the sources of the data include, molecular- dna and protein sequences, morphology, physiology, behavior. Classification: monophyletic group- includes the most recent common ancestor and all of its descendants, paraphyletic group- includes the most recent common ancestor, but not all the descendants, similarites of the flying vertebrates can be related to converted. Evolution: polyphyletic group- does not contain the most recent common ancestor for all the members in the group. Evolution: sieve tubes have evolved in two distantly related groups of plants.
