EVOLUTIONARY PROCESSES CREATE DIVERSITY >1.5 million known species! (and that’s only the eukaryotes) 10 million total? Make sense of it all through classification: taxonomy = categories phylogeny = ancestry aka SYSTEMATICS a HUGE task!

Carl Linne’ (aka Linneaus) Contributions: • shortened lengthy latin polynomial names to binomials (scientific name, i.e. Homo sapiens) • Created a hierarchy of groups into which all organisms are placed Broadest group = kingdom Most specific = species 1735

Linnean Taxonomy is a hierarchy of increasingly exclusive groups

Criteria for grouping is structure Homology: biochemistry genome embryology anatomy

Animalia Plantae Fungi Protista Animalia Chordata Mammalia Primate Homindae Homo sapiens H. ergastor H. erectus H. heidelbergensis etc

Same group, but how related? C. Darwin, 1837 E. Haeckel, 1866

Phylogenetic Tree attempts to explain: who is related when they shared an ancestor Phylogenetic Tree Speciation events create branches Junctions indicate a common ancestor

Time Polyphyletic Paraphyletic common ancestor to all but chicken (multiple phylogenies) not including any common ancestor Paraphyletic (part phylogeny) ancestor + some descendants common ancestor to all but chicken Monophyletic (one phylogeny) ancestor + all descendants Time

Cladogram a phylogeny based on a shared set of characteristics, for comparing organisms, relative to one another Outgroup jawless fish time is relative, not absolute

Interesting? Yes. Practical value? YES!