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Understand taxonomy, systematics, and phylogenetics to develop evolutionary trees and discover the Tree of Life. Learn about the three domains of life and the tools used for determining evolutionary relationships. Dive into cladistics, shared derived characteristics, and constructing phylogenetic trees. Enhance your knowledge of evolutionary history and relatedness among organisms.
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Chapter 26 Phylogeny and the Tree of Life
What you need to know: • The taxonomic categories and how they indicate relatedness. • How systematics is used to develop phylogenetic trees. • The three domains of life including their similarities and their differences.
Systematics: classifying organisms and determining their evolutionary relationships Taxonomy (classification) Systematics Phylogenetics (evolutionary history)
Tools used to determine evolutionary relationships: • Fossils • Morphology (homologous structures) • Molecular evidence (DNA, amino acids) Who is more closely related? Animals and fungi are more closely related than either is to plants.
Taxonomy: science of classifying and naming organisms • Binomial nomenclature (Genus species) Naming system developed by Carolus Linnaeus.
Taxonomic ranks are species, genus, family, order, class, phylum, kingdom, domain, etc • REMEMBER!! • Dear King Philip Came Over For Good Spaghetti • Dear King Philip Crossed Over Five Great Seas • Dear King Philip Came Over From Germany Singing • Your own???
Phylogenetic Tree • Branching diagram that shows evolutionary history of a group of organisms
Leopard Turtle Hair Salamander • Clade= A clade is a grouping that includes a common ancestor and all the descendants (living and extinct) of that ancestor. • Shared derived characteristics areused to construct cladograms Taxa- category of organisms Amniotic egg Tuna Four walking legs Lamprey Hinged jaws Lancelet (outgroup) Vertebral column Cladogram
a taxon is always most closely related to its The earliest diverging group within a clade A division into many members
A monophyletic taxon is defined as one that includes the most recent common ancestor of a group of organisms, and all of its descendents Monophyletic, paraphyletic, and polyphyletic groups A paraphyletic taxon as one that includes the most recent common ancestor, but not all of its descendents A polyphyletic taxon is defined as one that does not include the common ancestor of all members of the taxon
Constructing a phylogenetic tree Taxon by character matrix table A 0 indicates a character is absent; a 1 indicates that a character is present.
Various tree layouts Circular (rooted) tree Unrooted tree Rooted tree
Tree of Life • 3 Domains: Bacteria, Archaea, Eukarya