Unit 7 · 7.9 — Phylogeny [cite: 28, 44]

Everything to learn here

• Concept: Phylogenetic trees and cladograms visually and mathematically map out highly specific evolutionary hypotheses based heavily on morphological or molecular sequence data [cite: 13, 14, 49].
• Vocabulary: Outgroup — a specific baseline lineage that falls entirely outside the clade being actively studied, specifically used to root the tree and determine ancestral versus derived traits [cite: 49].
• Lab: Lab Skill: AP Biology Required Investigation — BLAST: Construct or meticulously interpret a cladogram using a molecular similarity matrix to identify the most closely related taxa and place derived traits [cite: 6, 13, 47].
• Skill: Identify an out-group by finding a lineage that lacks specific traits, such as a mantle or radula, shared by other groups.
• Concept: Phylogenetic trees are constructed using shared derived characters, with molecular data offering more precision than physical traits.
• Vocabulary: Vocabulary: Node — The branching point on a cladogram that represents the most recent common ancestor of the lineages following it.
• Concept: Cladograms and phylogenetic trees are dynamic hypotheses that scientists revise as they acquire new genetic or morphological data.

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