BSC 2011 Lecture Notes - Lecture 1: Synapomorphy
25 Aug 2016
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The idea that all living organisms are related to one another: everything comes from a single common ancestor. Phylogeny: the evolutionary history of these relationships from the common ancestor. Phylogenetic tree: a diagrammatic reconstruction of the history of life, note that this is a hypothesis, based on evidence, for what the true phylogeny is like to be. Lineage: a series of ancestor and descendant populations, shown as a line drawn on a time axis, when a single lineage divides into two (speciation) it is depicted as a split. The split occurs at the node on a branch of the phylogenetic tree: each descendant population gives rise to a new lineage. A and b share a more recent common ancestor, and thus they are more closely related: a and b form a clade a. B c: a and b and c form a clade, a and c do not form a clade.
