BIOLOGY 1M03 Chapter Notes - Chapter 27: Phylogenetic Tree, Permineralization, Chapter 27
26 Oct 2016
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Document Summary
Phylogenetic trees document the evolutionary relationships among organisms and are estimated from data. The fossil record provides physical evidence of past organisms. Phylogeny: the evolutionary history of a group of organisms. Node: a point in time when an ancestral species into two or descendant species. Tip: represents a group (species or taxon) that is living today or ended in extinction. Analysis of morphological and/or genetic traits aid in inferring historical relationships. Phenetic approach: computing a statistic that summarizes the overall similarity among populations based on data. Cladistic approach: constructing a tree based on synapomorphies shared between groups. Ancestral trait: a characteristic that existed in an ancestor. Derived trait: a modi ed characteristic of the ancestral trait found in a descendant. Homoplasy: traits are similar for reasons other than common ancestry (dolphin body vs shark body) Natural selection favours similar solutions to the same obstacle. Homology: traits are similar due to shared ancestry.
