Ch 4 - Systematics Flashcards
What is systematics concerned with?
biodiversity and evolutionary relationships
This is concerned with naming and classification of organisms
What is taxonomy
Carolus Linnaeous did this
Created the modern taxonomy system
What is a binomial system?
2 name system for species
What is the typal system?
a way of knowing if a type of species already exists
What is the taxonomical hierarchy?
Domain Kingdom Phylum Class Order Family Genus Species
Animalia is part of what taxinomical rank?
Kingdom
Classification is based on what?
phylogeny
What is phylogeny
perceived evolutionary relationships
If classification is done correctly, what kind of taxa is ideal?
monophyletic
What taxa is avoided when classification is done?
paraphyletic and polyphyletic taxa
What is monophyletic taxa?
includes ancestral organisms and all of its descendants
What is paraphyletic taxa?
including ancestral group but not all descendants
What is polyphyletic taxa?
includes descendants of 2 or more distantly related ancestors
What is the cladistics approach?
When an evolutionary relationship is represented by a common phylogenetic tree
-hypothesis of evolutionary tree
What are the steps to recognizing phylogeny
- Distinguish between homology and homoplasy
2. Distinguish between symplesiomorphy and synpamorphy
What is homology?
homologous structures are similar structures acquired from a recent common ancestor
-bone structures in bat wings and human hands
What is homplasy?
homoplastic structures are superficially similar structures that have evolved independently
- bat wings and bird wings
- common structures are formed under similar selection pressure systems.
What is reversal in homoplasy?
the loss of an evolved feature-tails in humans
What is symplesiomorphy?
having shared features from the earliest ancestor
-vertebral column
What is synapomorphy?
having a shared derived feature from a modern ancestor
- bipedal gait
- hair
- jaws
modern classification/systematics uses which approach?
cladistic approach-primarily synapomorphy to determine evolutionary relationships
What is the principle of parsimony?
most often used way of making a phylogeny tree-simplest relationship is likely the most correct
What does modern schematics rely heavily on?
genetic/molecular data
