syste

• Phylogeny is the evolutionary history or pattern of descent of a group of organisms
• Phylogenetic systematics, or cladistics, is used to infer phylogeny
• Phylogeny is commonly represented in the form of a cladogram or phylogenetic tree
• Lineages or clades are the lines in a cladogram
• Any branching of the cladogram represents lineage divergence or diversification, forming two separate lineages from one common ancestor
• Speciation is the process of forming two species from one
• Node is the point of divergence where the most common ancestor of the two divergent clades is located
• Internode is the region between two nodes
• Evolution may occur within lineages over time and is recognized as a change from a preexisting ancestral condition, also called plesiomorphic or primitive
• Plesiomorphy is the pre-existing ancestral condition
• Apomorphy is a derived character, also known as new
• Synapomorphy is an apomorphy that unites two or more lineages and is present in all clades
• Autapomorphy is an apomorphy that occurs in only one lineage, found in only one taxon and absent even in the closest