| A | B |
|---|
| Synapomorphies | Relatedness in cladistics is based off of shared, derived traits (synapamorphies) |
| Bifurcation | Species do not spontaneously evolve into many species, but go from one species to two and so on. Bifurcation describes this process |
| Monophyletic vs. Paraphyletic | A monophyletic group includes ALL descendants of a common ancestor (ex. turtles, lizards, crocs, birds). A paraphyletic group is arbitrary, and does NOT include all descendants of a common ancestor (ex. turtles, lizards, crocs, the "reptiles") |
| So WTF is a polyphyletic grouping? | A polyphyletic group is one that lumps unrelated organisms (descended from unrelated common ancestors) together. Ex. Lizards and Mammals |
| Classification used in binomial nomenclature | Kingdom, Phylum, Class, Order, Family, Genus, Species. Nomenclature: Genus name, species epithet |
| Plesiomorphy | "ancestral state," characteristic state taxon has retained from ancestor |
| Parsimony | The fewest steps to create a phylogeny |
| Heterochrony | Evolutionary change in the timing of a structure's development. Paedomorphosis = truncated shape development (infant-like); peramorphosis = extended shape development |
| Isometry vs. allometry | Isometry is a change in size of proportions (shape still geometrically similar). Allometry is change in shape that will maximize surface area (thus offsetting SA:vol imbalance) |
| Issues of being big | Volume easily exceeds SA with isometric growth. Invagination can help this by increasing the SA while maintaining the same volume. Circulatory systems are also used to reduce reliance on diffusion |
| Vertebrate diversity | 63,000 living species (Max was mid-Miocene) Vastly diverse sizes, habitats, feeding strategies (herbivory vs. carnivory), and repro. diversity (anisogamy w/ 1 larger gamete, sex-change, parthenogenesis) |
| Non-amniotes include: | Jawless hagfishes/lampreys; Chondrichthyes; Osteichthyes; Amphibia |
| Chondrichthyes (briefly) | Non-amniotes. Have cartilaginous skeletons. Include sharks and rays (Elasmobranchs), and chimeras (Holocephalii) |
| Osteichthyes (briefly) | Non-amniotes. Bony fishes: Actinopterygians (ray-finned fishes, includes teleosts); and Sarcopterygians (lobe-finned fishes, include coelacanths/lungfish ) |
| Amphibia (briefly) | Non-amniotes. Complex life-histories (semi-aquatic w/ larval phase), bare skin for exchange of water, ions, gasses |
| Amniotes have what membranes? | 3: Amnion, chorion, allantois |
| Amniotes include: | Turtles; Lepidosauria; Archosauria (Crocs, Theropods, Birds); Synapsida (includes mammals) |
| Lepidosauria (briefly) | Amniotes. Tuatara, lizards, snakes etc. |
| Archosauria (briefly) | Amniotes. Include Crocodiles and Theropods (theropod dinosaurs and birds) |
| Birds (briefly) | Amniotes. Included in Archosauria. Origin in Mesozoic, have endothermy, and feathers that were once used for courtship but now are used for flight |
| Synapsida (briefly) | Amniotes. Includes mammals (monotremes and meta/eutherians) |
| Monotremes vs. Theria | Amniotes. Monotremes are egg-laying, like platypus. Eutherians are placental mammals. Metatherians are marsupials. |
| Homology vs. Homoplasy | Homology refers to a trait that is similar due to a common ancestor. Homoplasy means a trait serves a similar function due to convergent evolution, but isn't derived from a common ancestor |
