How Long Ago? Extant 0.5 Land! Animals 1 Multicellular 2 Multicellular Animals Myxozoans Protozoans Tracheophytes Bryophytes True Fungi Slime Molds Red algae Brown Algae Green Algae Chrysophytes Euglenoids Archezoans Archaebacteria Bacteria 0.5 Land! Animals 1 Multicellular 2 First Eukaryotes Extinct 3 Cyanobacterial Oxygen Long Time with Prokaryotes only 4 BYBP Origin of Life Original Cell

Evidence Categories History - clearer recently, more obscure anciently Fossils - stratigraphic depth, isotope decay, etc. Chemical - metabolic products such as O2, Ss Molecular - DNA sequence alterations, etc. Developmental sequences - onto- phylo- geny Biogeography - Pangea, Gondwana & Laurasia

How do we know the Evolution Pathway? Phylogenetic Systematics Inferences from comparison of extant organisms Characters-Attributes of the organism Anatomy Morphology Development Physiology Macromolecule Sequences Polarizing Character States Plesiomorphies-Ancient, shared by descendants Apomorphies-More-recent derivatives Synapomorphy-Shared among related organisms Autapomorphy-Found only in one organism Use of outgroup to compare to ingroup

Typical Cladogram Present Extant A Extant B A’ A” A’” This branching of evolution is called cladogenesis. Extinct Transitional Forms A’ is the common ancestor of extant A and extant B Time This straight line of evolution is called anagenesis. Common Ancestor Ancient

Typical Cladogram Present Extant A Extant C Extant B A’ A’ A B constitute a clade A” C are a grade (is paraphyletic) A” Time A” C A’ A B are a clade A’” A’ A B is the sister group of C Common Ancestor Ancient

Typical Cladogram Present Extant A Extant C Extant B Extant D Extant E D A””’ E are a ? clade A”” Extinct! Common ancestor + A””’ D E are a ? grade A” Time A’” The ABC clade may be, say, a genus. The DE clade may be another genus… in the same family Common Ancestor Ancient The ABCDE clade would be the family

Typical Cladogram Present Extant A Extant B Extant C Extant D Extant E On the other hand… A””’ Extinct! AB are a genus C is a monotypic genus DE are a genus A” Time A”” A’” ABC might be one family DE are in another family Common Ancestor Ancient ABCDE might constitute an order

Protists are polyphyletic (unnatural taxon) Extant Multicellular Animals Myxozoans Protozoans Tracheophytes Bryophytes True Fungi Slime Molds Red algae Brown Algae Green Algae Chrysophytes Euglenoids Archezoans Archaebacteria Bacteria Animals and Fungi are a clade! Plants are a clade (monophyletic) Extinct Eukaryotic organisms are a clade Prokaryotic organisms are a grade (paraphyletic) Living organisms are part of one clade Original Cell

How do you DO classification? Warmup! Get with a partner to form a team Look over the cards you are given for your team Every group gets the same set of 8 cards Bob Sue Deb Lou Jen Cal Hal Val Sort the cards into what you believe may be natural groups Names do not count, use only shapes shown on card Decide who will tell the class how you sorted your groups What theme unites/defines each group

How do you DO classification? Sharing our Results

The Forest Meet! This game is a cross-country race in a forest All runners enter the forest by a single south entrance The finish line is the northern boundary of the forest Runners need not exit at any particular place at the finish There are many trails through the woods Trails only bifurcate (form two branches) at forks Trails never join together or rejoin after forking Along the trail straightaways are check-in stations At each check-in station, a worker has a unique stamp Each runner has a card that is stamped as s/he passes a station Runners are not allowed to retrace a path All runners must finish the race Using the punch cards handed in at the finish line: Sketch the trail map Show all station locations (on the straightaways) Mark the exit used by each runner

The Forest Meet Sharing our Results Bob Sue Deb Lou Jen Cal Hal Val  x          

The Forest Meet Sharing our Results Bob Sue Deb Lou Jen Cal Hal Val Total  x 8  5  2  1  4     3  

The Forest Meet Sharing our Results Runners can finish anywhere along this northern edge All of the runners passed the circle station, so this station must be near the start  Start

The Forest Meet Sharing our Results Bob Sue Deb Lou Jen Cal Hal Val Total  x 8  5  2  1  4     3  

The Forest Meet Sharing our Results Runners can finish anywhere along this northern edge Five of the runners passed the teardrop station, but three did not, so our 8 runners must have divided into two groups Bob, Deb, Cal Sue, Lou, Jen, Hal, Val   Start

The Forest Meet Sharing our Results Bob Sue Deb Lou Jen Cal Hal Val Total  x 8  5  2  1  4     3  

Runners can finish anywhere along this northern edge The Forest Meet Sharing our Results Hal Runners can finish anywhere along this northern edge Because paths do not rejoin, Hal is separated and thus we can draw him at the finish line Four runners of the group of five passed the diamond station, but Hal did not, so he split away before this station Sue, Lou, Jen, Val Bob, Deb, Cal Sue, Lou, Jen, Hal, Val    Start

The Forest Meet Sharing our Results Bob Sue Deb Lou Jen Cal Hal Val Total  x 8  5  2  1  4     3  

The Forest Meet Sharing our Results Hal Finish Line Bob, Deb, and Cal all passed the triangle station so it was along the path they shared Sue, Lou, Jen, Val Bob, Deb, Cal     Start

The Forest Meet Sharing our Results Bob Sue Deb Lou Jen Cal Hal Val Total  x 8  5  2  1  4     3  

The Forest Meet Sharing our Results Bob Hal Finish Line Jen and Lou passed the heart station, but Sue and Val passed the spade station, so the group of four divided Deb, and Cal passed the star station, but Bob did not, so the group divided Jen, Lou Sue, Val Deb, Cal   Sue, Lou, Jen, Val  Bob, Deb, Cal     Start

The rest are autapomorphies The Forest Meet The rest are autapomorphies Bob Sue Deb Lou Jen Cal Hal Val Total  x 8  5  2  1  4     3  

The Forest Meet Autapomorphies! Bob Cal Deb Hal Jen Lou Sue Val    Deb, Cal       Notice the runners are in alphabetical order. But this is not the only solution All branches can be rotated: e.g.: Lou before Jen Sue-Val before Jen-Lou    Start

The Forest Meet! But Wait! We have one really-slow runner just exiting! Here is his card…figure out his pathway

The Forest Meet Sharing our Results Bob Sue Deb Lou Jen Cal Hal Val Ross  x          

The Forest Meet Bob Cal Deb Hal Ross Jen Lou Sue Val           What did Ross do? What is parsimonious? Are our ideas wrong?   Maybe Ross followed Hal.. Then hit a rougue station?  Start

The Clade Race! This game is a cross-country race in a forest All runners enter the forest by a single south entrance The finish line is the northern boundary of the forest Runners need not exit at any particular place at the finish There are many trails through the woods Trails only bifurcate (form two branches) at forks Trails never join together or rejoin after forking Along the trail straightaways are check-in stations At each check-in station, a worker has a unique stamp Each runner has a card that is stamped as s/he passes a station Runners are not allowed to retrace a path All runners must finish the race Using the punch cards handed in at the finish line: Sketch the trail map Show all station locations (on the straightaways) Mark the exit used by each runner 1. This game represents the evolution of some related organisms 2. The organisms are believed to be a clade (w/common ancestor) 3. The organisms we are using are all extant (none are fossils) 4. We make no assumptions about possible phenotypes observed 5. We make few assumptions about the evolution pathway • Cladogenesis divides one species into two species • We assume there is no convergent or parallel evolution 6. Anagenesis is expected to occur between generations 7. Evolution shows its record of changes in the genotype 8. The record of evolution in genotype is shown in the phenotype 9. Evolution is permanent; we assume no reversals of states 10. In this study, we are using no fossils of extinct clade members 11. Using the phenotypes observed in the extant organisms: • Sketch the cladogram • Show the location of character state transitions • Show the relationships among the taxa

How do you DO cladistics? Look at a group of organisms that you think are related Find a not-too-distantly related (primitive?) out-group Select characters that will help to distinguish the organisms Polarize the character states by: Stratigraphic sequence (fossil sequence) Developmental sequence (ontogeny recaps phylogeny) Outgroup comparison Build a data matrix Group by number of synapomorphies (shared derived) Sketch possible cladograms Seek simplest (most parsimonious) cladogram