BIO153H5 Lecture 2: Lecture 2 - The Tree of Life
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Topic: the tree of life / phylogeny y displaying evolutionary relationships y the parts of a tree y deciding on a tree. First point: there are 10 100 million species, approximately. Fortunately there is a method that we have used to put order to all of these species, the tree of life or phylogeny. The current system that we use is slightly more complex than earlier forms. Classification using this method is based upon similarity, starting with broad, general shared characteristics and moving towards more specific characteristics that branch from the main tree. To recap, the taxonomic groups are as follows: domain, super-group, kingdom, phylum, class, order, Family, genus, and species. (dutch kings play chess on finely grained sand. ) Phylogenetic trees have different parts, starting with the root. The splitting of a branch or root is called a node and polytomy is when more than one branch forms from a node.