TAXONOMY

• Taxonomy is the science of grouping and naming organisms.

• Classification the grouping of information or objects based on similarities.

Why use a dead language?

•We only know about a fraction of the organisms that exist or have existed on Earth.

•Taxonomists give a unique scientific name to each species they know about whether it’s alive today or extinct.

• The scientific name comes from one of two “dead” languages – Latin or ancient Greek.

Devil Cat

Ghost Cat

Mountain Lion

Screaming Cat

Puma

Florida Panther

Cougar

•There are at least 50 common names for the animal shown on the previous 7 slides.

•Common names vary according to region.

•Soooo……why use a scientific name?

    •a two name system for writing scientific names.•The genus name is written first (always Capitalized).     •The species name is written second (never capitalized).     •Both words are

italicized if typed or underlined if hand written.

Example: Felis concolor or F. concolor

Which is the genus? The species?    

Binomial Nomenclature

Phylogeny, the evolutionary history of an organism, is the cornerstone of a branch of biology called systematic taxonomy.

                        

A phylogenetic tree is a family tree that shows a hypothesis about the evolutionary relationships thought to exist among groups of organisms. It does not show the actual evolutionary history of organisms.

Why a hypothesis?

Phylogenetic trees are usually based on a combination of these lines of evidence:

    Fossil record

    Morphology

    Embryological patterns of development

    Chromosomes and DNA

Fossil

Morphology

Homologous Structures

Adaptive Radiation -

modifies

homologous

structures

Modifies homologous structures

These animals have evolved similar adaptations for obtaining food because they occupy similar niches. What can you infer about their phylogeny from their geographic locations?

Convergent Evolution

Analogous Structures  - 

•Traits that are morphologically and functionally similar even though there is no common ancestor.

Convergent evolution leads to……….

Embryology

Cladistics - is a relatively new system of phylogenetics classification that uses shared derived characters to establish evolutionary relationships. A derived character is a feature that apparently evolved only within the group under consideration.

DNA

A phylogenetic tree based on a cladistic analysis is called a cladogram.

What derived character is shared by all the animals on the cladogram on the next slide?

The acacia and its ants are an example of coevolution. Eachinfluences the others evolution.

Can you think of any other examples ofcoevolution?

• A key is a device for easily and quickly identifying an unknown organism.

• The dichotomous key is the most widely used type in biological sciences.

• The user is presented with a sequence of choices between two statements, couplets, based on characteristics of the organism. By always making the correct choice, the name of the organism will be revealed.

The Dichotomous Key

1.  

A. one pair of wings

B. Two pairs of wings

The Kingdoms 1. Bacteria

– Includes other members of old kingdom Monera

2.– Protist3.– Fungi 4.– Animalia 5.– Plantae

The major classification levels,from most general to most specific

(several of these have subdivisions)

A group at any level is a taxon.

Kingdoms are divided into groups called phyla Phyla are subdivided into classes

Classes are subdivided into orders

Orders are subdivided into families

Families are divided into genera Genera contain closely related species

Species is unique

Categories within Kingdoms

•Phylogeny•Systematics Hypothesis•Cladistics •Derived character •Cladogram •Dichotomous Key

•Classification•Taxonomy•Aristotle•Linnaeus •Kingdom•Phylum •Class

•Order•Family •Genus•Species•Common name•Scientificname•Binomial nomenclature