1. Classification
BIO – Explain the historical development and changing nature of classification systems.
BIO – Analyze the classification of organisms according to their evolutionary relationships (including dichotomous keys and phylogenetic trees).

2. Taxonomy
Taxonomy is the science of describing, naming, and classifying organisms.
The Linnaean System
Carolus Linnaeus devised a seven-level hierarchical system for classifying organisms according to their form and structure.
From the most general to the most specific,the levels are kingdom, phylum, class, order, family,genus, and species.

4. Dumb King Phillip Cried Out “For Goodness Sake!”
Current system (with human classification):
Domain (3) – group of similar kingdoms (Eukarya)
Kingdom (7) – group of similar phyla (Animalia)
Phylum – group of similar classes (Chordata)
Class – group of similar orders (Mammalia)
Order – group of similar families (Primates)
Family – group of similar genera (Hominidae)
Genus – group of similar species (Homo)
Species – a group of organisms that can interbreed and produce fertile offspring in nature (H. sapiens)
Dumb King Phillip Cried Out “For Goodness Sake!”

5. Binomial Nomenclature
An important part of Linnaeus’s system was assigning each species a two-part scientific name— a genus name, such as Homo, and a species identifier, such as sapiens.
This system of a two-part name is known as binomial nomenclature.

6. Examples of Scientific Names
Felis catus
Panthera leo
Homo neanderthalensis

7. Examples of Offspring between Two Non-Species
Horse x donkey = mule
Lion x tiger = liger
Zebra x donkey = zonkey
Camel and llama = cama

8. Same Species…Different Subspecies
Canis lupus – gray wolf
Canis lupus familiaris – domestic dog
subspecies

9. Which two of these organisms are most closely related
Which two of these organisms are most closely related? Ursus americanus, Lepus americanus, Ursus arctos

10. Phylogenetics
A modern approach to taxonomy is systematics, which analyzes the diversity of organisms in the context of their natural relationships.
When classifying organisms, scientists consider fossils, homologous features, embryo development, chromosomes, and the sequences of proteins and DNA.

11. Phylogenetics
Molecular similarities (such as similar amino acid or nucleotide sequences), as well as chromosome comparisons, can help determine common ancestry.

12. Phylogenetics
A phylogenetic diagram (aka cladogram) displays how closely related organisms are thought to be.

13. Tree of Life
The phylogenetic analysis of rRNA nucleotide sequences by Carol Woese led to a new “tree of life” consisting of three domains aligned with six kingdoms.
The three domains are Bacteria, Archaea, and Eukarya.

14. Domain Bacteria
Domain Bacteria aligns with Kingdom Eubacteria, which consists of single-celled prokaryotes that are true bacteria.
These are the bacteria that live in and on your body, keeping you healthy and every once in a while making you sick.
Most bacteria fall into this domain.
Their cell walls contain peptidoglycan.

15. Domain Archaea
Domain Archaea aligns with Kingdom Archaebacteria, which consists of single-celled prokaryotes that have distinctive cell membranes and cell walls.
These bacteria tend to live in extreme environments.
Their cell walls do not contain peptidoglycan.
Their ribosomes are more like those found in eukaryotes than those found in true bacteria.

16. Domain Eukarya
Domain Eukarya includes the kingdoms Protista, Fungi, Plantae, and Animalia.
All members of this domain have eukaryotic cells.
Animalia – no cell walls
Plantae – cell walls made of cellulose
Fungi – cell walls made of chitin
Protista – anything with eukaryotic cells that doesn’t fit in animalia, plantae, or fungi kingdoms