Phylogeny and the Tree of Life 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.

(evolutionary history) 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.

Dear King Philip Came Over For Good Spaghetti 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

Cladogram: diagram that depicts patterns of shared characteristics among taxa Clade = A clade is a grouping that includes a common ancestor and all the descendants (living and extinct) of that ancestor. Shared derived characteristics are used to construct cladograms Taxa- category of organisms Turtle Leopard Hair Amniotic egg Four walking legs Hinged jaws Vertebral column Salamander Tuna Lamprey Lancelet (outgroup) Cladogram

a taxon is always most closely related to its The earliest diverging group within a clade A division into many members

Monophyletic, paraphyletic, and polyphyletic groups A monophyletic taxon is defined as one that includes the most recent common ancestor of a group of organisms, and all of its descendents 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.

Branch lengths can represent genetic change

Branch lengths can indicate time

Various tree layouts Circular (rooted) tree Unrooted tree Rooted tree

Tree of Life 3 Domains: Bacteria, Archaea, Eukarya