BOT101: Systematics

Systematics: the study of biodiversity and evolutionary history on Earth.


1. Taxonomy: naming & classification system

binomials: species names
type specimen: a reference organism
taxa (taxon): a taxonomic group of any rank: species, genus, family, class
Carl Linnaeus developed the binomial and hierarchical system of classification (AKA the Linnaen Classification System)

EXAMPLE:   Zea mays (Corn)

Species: Zea mays
Genus: Zea
Family: Poaceae
Order: Poales/Commelinales
Class: Monocotyledones
Phylum: Anthophyta
Kingdom: Plantae
Domain: Eukaryotes

Here’s a way to remember the hierarchy ⇒ King Phillip Came Over For Grape Soda

A species name, or binomial, includes BOTH the genus (Zea) & specific epithet (mays). Binomials are always italicized and the specific epithet is never capitalized.


2. Phylogeny: system of ancestor/descendent relationships between taxa.

phylogeny is relative to the taxa or group in question.

Monophyletic (Clade): a group with a common ancestor and ALL descendents
Paraphyletic (Grade): a group with a common ancestor and SOME descendents
Polyphyletic: a group without a common ancestor

Phylogenypt.1.jpg

Apomorphy: refers to a special or derived trait/character
Synapomorphy
: a shared derived trait/character
Plesiomorphy: refers to a primitive or ancestral trait/character
Symplesiomorphy: a shared primitive trait/character

Homoplasy: a trait/character evolved independently in 2 places


| WHY? |

1.  Each species has a unique name for simplicity and ease of communication
2.  Bringing order to a YUGE amount of biodiversity
3.  To show evolutionary relationships (whos related to who)


Feel free to leave comments, questions, or any concerns