BIO153H5 Lecture Notes - Archaea, Cell Membrane, Beta-Carotene
Document Summary
Week 2- lecture 3- tree of life ii- january 15, 2013 trees should reflect relatedness. Phylo trees show evolutionary relationships between organisms. Phentic approach is a calculation of overall simularities. Cladistic approach: based on characters shared by group of organisms. Character can be based on morphology, dna, rna, proteins. Plesiomorphic characters are ancestral. means a character that is probably very close to the stem of the tree. Apomorphic character which means far-close to the tip, not close to the root. in this the characters are derived. A synapomorphics charcter is a shared, derived characters. they reflect a common ancestor. Monopheltic group is where you can snip the branch and the two will be connected. Monoppheltic is closely related to each branch. Parapheltic is a branch that is all closely relaed except one org on that branch. Polypheltic is a branch that is all closely related but is also closely related iwht another branch.
