Practical #2 - Taxonomy Flashcards
Define Taxonomy
The field of biology the is involved in naming, describing, and classifying organisms both fossil (extinct) and living (extant).
Define Classification
Classification is one branch of taxonomy where various things are identified and lumped together into groups. Classification orders and ranks tings into a series of hierarchical levels.
Define Systematics
The field of biology concerned with the identification of the evolutionary relationship among species through time
What is Phylogeny
Pattern of evolutionary descent of all of the taxa used in a classification of organisms
What is a “taxa?”
Monophyletic groups of organisms that can be recognized as members of the group on account of their shared characteristics
What is our definition of species?
A species is a group of organisms that potentially can interbreed and reproduce fertile offspring. This is all the -biological species concept
What is a population
A group of organisms of one species living in a defined area.
What are the codes for naming Animals, Plants, Bacteria?
International Code of Zoological Nomenclature International Code of Botanical Nomenclature International Code of Nomenclature of Bacteria
How to scientifically name a species?
- 2 parts
- First word = genus
- Second word = specific epithet
- The first letter of the genus is capitilized. The second word is all lower case
- The entire name is italicized or underlined
List the 7 taxonomic levels, High to low.
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
Trinomial Nomenclature
- To indicate a specific subspecies a third name is used in scientific naming
- Ex: Homo Sapiens sapiens - refers to “modern” humans
What is a shared characteristic?
- Shared characteristics are based on easily recognizable features of the objects: their shapes, sizes, colors, or functions
Artificial Classification vs Natural Calssification
- Artifical classifies based on a few shared features which may not have any evolutionary significance
- Think of grouping flying vs non-flying organisms
- Natural groups together organisms descended from common ancestors
What are analgous structures?
- Analgous structures are similar in function, but the underlying structure and development of these structure are different
Describe Homology
- Similarties based on shared ancestry
Convergent Evolution (Analogy)
- Similarties that have arisen due to natural factors
- Like white fur - protecting from predators/providing camoflouge. White fur on arctic hares and Polar bears are not homologous
Analogous Structures
- Thinkg of a bird wing and a butterfly wing
- Both are wings, but their evolutionary and function are different
Homologous Structures
- Bird wing and bat wing as Forelimbs
- Homologous strucutres may have different function, but the underlying structure, development, and physiology are the smae
Phenetics vs Cladistics
- Phenetics - the calssification of a group of organisms reflects the overall similaity of the species
- Cladistics refelcts the closeness in terms of shared characteristics from common descent from older species
Subjective Classification
where some characteristic is chosen arbitrarily, or is chosen because of some utilitarian reason
Objective Classification
unambiguous features to classify animals
Ex: Presence or absence of fur
Monophyletic Taxon
includes the single ancestor species and all species descended from that ancestral species
Polyphyletic Taxon
Missing the common ancestor of all members of the identified group
Paraphyletic Taxon
Has the common ancestor and some, but not all of the descendant species.
Plesiomorphy
Primitive or ancestral trait
Symplesiomorphy
- Shared primitive trait
- Can be found in groups other than the clade being analyzed
Apomorphy
Specialized or derived trait
Synapomorphy
- Derived trait shared by two or more groups in a clade
Autapomorphy
Derived trait that is unique to one group in a clade
What is 1 problem with Phenetics?
- Convergent Evolution of analogous traits
- Because of convergent evolution, similar traits that are not due to common acnestry may cause mistakes to be made when classifying
What are 3 problems with Cladistics
- Determining what are derived traits and what are primitive traits
- Cladograms do not directly tell which species arose from which species
- Cladograms do not tell how long ago each group branched away from each other
