| A | B |
|---|
| traditional taxonomy weighs characters according | presumed biological or evolutionary significance |
| traditional taxonomy line of descent is considered as well (and may incorporate | cladograms), but naming allows for some paraphyletic groups |
| traditional taxonomy example | classifying birds |
| traditional taxonomists view feathers as being so important that | birds are placed in own Class (thus making Reptilia paraphyletic in their taxonomies) |
| cladists put birds with reptiles to make | Reptilia monophyletic |
| if you are after phylogeny, | cladistics is clearly the way to go – any traditional taxonomy that is at majors odds with phylogeny is likely to lose out |
| most biologists use traditional taxonomy informed (and often revised by) | cladistics; that is what we will use in this course |
| traditional taxonomy is the old way and is being replaced in | many cases with cladistics |
| characters useful for classification | morphology, nutrition mode, cell structure, 4. chemistry, 5. reproductive traits, 6. many others |
| morphology | form, such as unicellular or multicellular, etc |
| nutrition mode | autotroph or heterotroph, etc |
| cell structure | presence or absence of a nucleus; presence or absence of a cell wall, etc |
| chemistry | cell wall makeup, protein sequences, DNA sequences, etc |
| reproductive traits | sexual, asexual, etc |
| The most widely accepted classification system today includes | three domains and six kingdoms |
| Two domains consist of prokaryotes | organisms with no internal membrane-bound organelles (and thus no true cellular nucleus) |
| Domain Archaea | Kingdom Archaebacteria |
| Domain Bacteria | Kingdom Eubacteria |
| One domain, Eukarya, consists of | eukaryotes |
| eukaryotes | organisms with a discrete cellular nucleus (and other internal membrane-bound organelles); it is divided into four kingdoms |
