BI111 Lecture Notes - Lecture 5: Recapitulation Theory, Dactyly, Parallel Evolution
Document Summary
Twin goals of systematics : reconstruction of evolutionary history and classification of species. Phylogenetic trees come about through successive events of speciation(branching), in which one species gives rise to two(or more!) Reconstructing these trees requires comparison of traits (with shared genetic ancestry) in multiple species: homologies are good analogies are not. Binary nomenclature: genus and species reflect the nested hierarchy of life) Taxon designation has 3 components: name: what group does it belong to, rank (where does it fit into phylogeny, content (relevant to species concept) Sharks, dolphins all have similar morphology(similar profiles), similar selective pressures to fill nice (homoplasties) Resemblance due to recent common ancestor (homologies) Converged on the same phenotype with different starting types. Similarities which have risen due to convergent evolution due to similar resemblance. Homologous structures reflect underlying genetic similarities: e. g: bones that support wings of bats, birds and pterosaur all look like modifications of pentadactyl limb, develop from comparable embryonic structures.
