recognition, identification and names
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Recognition, Identification and Names. Spring 2013. Recognition versus Identification. Recognition relies upon previous experience with the organism. You “know” it is this, because you’ve seen it before, and have learned the name from some authority. - PowerPoint PPT PresentationTRANSCRIPT
Recognition, Identification and Names
Spring 2013
• Recognition relies upon previous experience with the organism. You “know” it is this, because you’ve seen it before, and have learned the name from some authority.
• The process of identification relies upon an analytical review of the characters observed, and following a logical order of inclusion and exclusion, to finally arrive at the name through the use of identification keys, for example, or some other resource.
• Confirmation of the name is done through comparison with a known “standard” (e.g., checking the specimen against previously identified specimens in a reference collection, the herbarium), or consulting with an authority who has much experience with the plant group, or checking a published treatment of the plant diversity of your region (flora) or a photographic atlas or web resource for that group of plants.
Recognition versus Identification
Elements of UnderstandingBiological Diversity
Description of Diversity
Classification of Diversity
Naming of Diversity
Identification of Diversity
Elements of UnderstandingBiological Diversity
Description: requires observation and measurement of characters and their states and synthesis of this information
Classification: requires hierarchical organization of taxa based on evolutionary relationships
Naming: requires following nomenclatural conventions and enables communication
Identification: requires tools such as keys that are based on previous description, classification, and naming of taxa
Description• Provides some basic identifiable set of
characteristics to associate with the organism.
• Can be as general or as detailed as practicality dictates.
• Needs to contain enough data to provide adequate discrimination between similar organisms.
• Needs terminology.• Descriptions are linked with a name when
there is consistency in the set of observed characters for a given organism.
Fig. 16.2
Description of Bambusa fromthe Flora of China
Classification• Classification provides ORDER to the group of entities.
• Relies on observations, many definable and comparable characters, and an ability to discern them.
• Completely effective classifications can be artificial, that is, not necessarily reflecting evolutionary relationships: i.e., trees vs. shrubs vs. herbs.
• But modern classifications are based on evolutionary history (phylogeny) because this provides predictive power.
• Biological classifications are hierarchical.
Hierarchical (nested) categories and phylogeny
PHYLUM
CLASS
ORDER
FAMILYGENUS
TIME
…have only RELATIVE meaning, not absolute meaning! …are artificially created to accommodate different hierarchical levels of organization.
…rely on inclusiveness of various shared characteristics that all members of the group should possess.
…are subject to modification as data accrue!
Taxonomic Ranks…
Naming and Nomenclature • We need names to communicate about plants with
others.• Organized system of names enables fitting the plant
into an accepted scheme.• Following formal naming rules is nomenclature (International Code of Botanical Nomenclature; ICBN)• The system must allow for changes as new
information (and other species) are discovered.• Will discuss the rules of nomenclature in more
detail later in the semester.
Names of taxonomic ranks: standardized endings*
Kingdom Chlorobionta (Viridiplantae) Phylum/Division: Magnoliophyta
(Angiospermae) Class: Liliopsida Order: Poales Family: Poaceae
Subfamily: Bambusoideae
*These are for plants and fungi; there are different ones for animals.
Names of taxonomic ranks: standardized endings*
Kingdom Chlorobionta (Viridiplantae) Phylum/Division: Magnoliophyta
(Angiospermae) Class: Liliopsida Order: Poales Family: Poaceae
Subfamily: Bambusoideae
*These are for plants and fungi; there are different ones for animals.
Name of a bamboo
Class: Liliopsida (Monocots) Order: Poales Family: Poaceae
Subfamily: Bambusoideae Genus: Chusquea Kunth Species: Chusquea pohlii L. G. Clark
Genus names
• Do not have standardized endings• Must be italicized• Often the name of the author follows
the genus name
Chusquea Kunth
Species names
• Are always a binomial (genus name or epithet + species name or epithet)
• Must be italicized• Often appear with the name of the
author(s) of the species
Chusquea pohlii L. G. Clark
Classification and Names
• Ideally, classification should reflect phylogeny
• And names should reflect the classification and phylogeny
Identification
• Relies on previous description, classification, and naming of taxa
• Keys are the primary means of plant identification
• Keys can take different forms, but the most common is still the dichotomous key
Dichotomous keys
• Consists of a series of two contrasting statements (each called a lead); each pair of statements is called a couplet
• Should be able to eliminate one set of possible identifications at each couplet
• Rules for constructing dichotomous keys are found on pp. 29-31 of the lab manual
Fig. 15.1
http://www.eeob.iastate.edu/research/bamboo/keys.html
Interactive keys