BIO 402: Field Biology

TAXONOMY AND CLASSIFICATION SYSTEM

WHY A CLASSIFICATION SYSTEM?

Each species should have a name so two persons can talk to another and know what they are talking about

Two types of names are in use:

1. Common – a name used by most persons, in the local language
   major problem, many species have many common names
2. Scientific – name based in Latin
   same in all places since one language (one correct name)
   problem of not many know Latin
   has two parts, generic name and specific name
                 two parts together = species
   Ex.:        Homo sapiens (humans)
                Quercus alba (white oak)

SPECIES

Hard to define species: our mechanisms are different than those the actual individuals use to distinguish themselves

Methods we use to recognize species:

• Morphology (external)
• Anatomy (internal)
• Reproductive behavior (animals & plants)
• Chromosome number
• Metabolites
• Nucleic acid sequencing (DNA & RNA)

Historically we have defined a species as:  all individuals which look alike
    numerous problems of sexual dimorphism (ducks)

Have developed a biological, non-biased method:

    all individuals which can potentially mate and produce viable offspring
    but not always able to observe differences

TAXONOMY and SYSTEMATICS

Taxonomy = branch of science dealing with placing a name with specific entities

Methods used to do such:
    morphology
    anatomy
    reproductive behavior

Systematics = branch of science dealing with evolutionary relationships between groups of organisms

Methods used to do such:
    chromosome number
    metabolites
    nucleic acid sequence

LEVELS OF CLASSIFICATION

Species = smallest reproductive unit

Genus = all related species

Family = all related genera

Order

Class

Phylum (animals) or Division (plants & fungi)

Kingdom

Domain