Introduction to Diversity

Tree of Life LUCA: Last Universal Common Ancestor (3.5 - 3.8 Ga) Domain Bacteria Domain Archaea Domain Eukarya 1.8 Ga Aquifex Thermotoga Bacteroides Cytophaga Planctomyces Cyanobacteria Proteobacteria Spirochetes Gram positives Green Filamentous Bacteria Pyrodicticum Thermoproteus T. celer Methanococcus Methanobacterium Methanosarcina Halophiles Animals Fungi Plants Ciliates Flagellates Trichomonads Microsporidia Diplomonads Slime Molds Entamoebae Solid Earth forms (4.6 Ga*) *Billion Years Ago First Cells (3.8 Ga) Liverworts Mosses Hornworts Lycophytes Ferns Gymnosperms Angiosperms E. coli Salmonella Heliobacter Chytridiomycota Zygomycota Glomeromycota Ascomycota Basidomycota Porifera Cnidaria Ctenophora Phronida Ectoprocta Brachiopoda Echinodermata Chordata Platyhelminthes Annelida Arthropoda Mollusca Rotifera Nemertea Nematoda Urochordata Cephalochordata Myxini Hyperoartia Chondrichthyes Actinopterygii Actinistia Dipnoi Amphibia Reptilia Mammalia Photo by Tom Oates http://dx.doi.org/10.1371/journal.pbio.0030102 Prototheria Marsupials Eutherians Xenarthra Epithera Ferae Lipotyphla Archonta Ungulata Primates Scandentia Dermoptera Chiroptera Lemurs and Lorises Tarsiers New World Monkeys Old World Monkeys Gibbons Orangutans Gorillas Chimpanzees Humans Photo by Terry Goss Photo by Stan Shebs How Are These Built? Phylogenetics: Evolutionary history of a species (or group of related species) Most modern phylogenetic trees are built using molecular data Early phylogenetic tree
Haeckel, 1866 Monophyletic group: ancestral species and ALL descendants (ex: all reptiles, including birds)

Paraphyletic group: ancestral species and SOME descendants (ex: non-avian reptiles)

Polyphyletic group: lacks a common ancestor (ex: warm-blooded animals [birds and mammals]) Cladogram Maximum Parsimony The most correct tree has the fewest independent evolutionary events

Also called Occam's Razor Not always true... Clade: Group of related species Species begin divergence from common ancestor Mutations! DNA sequences don't look very similar anymore.... but computers are really smart. (actually its the programmers)