BIOLOGICAL SYSTEMATICS
Systematics = Taxonomy + Phylogeny
Systematic classification of organisms & the evolutionary Phylogeny & Taxonomy
relationships among the How 1 organism is closely related to another
Study of patterns of diversity in living & fossil organisms How branching/diversification of 2/3 organisms from 1
Foundation of organismal biology single ancestor
The theory of evolution, which unifies modern biology, Taxonomy
emerged from systematics Can change overtime
Genus, species, order
Phylogeny
Support w/ evolutionary relationship
PHYLOGENY
A natural system of classification that is based on the Cladistics
evolutionary history/genealogy shared by a grp of Systematic method of classification w/c uses shared
organisms derived characters to make a cladogram
Tool used for Phylogeny Classifying organisms based on the characteristics they
Evolutionary relationship may/may not have
An analytical method of hypothesizing
2 types of representation in Phylogeny Outgroup
Phylogenetic Tree “Tree of Life” Species that have more ancestral characters w/ respect to
Involves evolutionary times the other organisms being compared
o Time it takes for diversification Oldest & simplest organism
Established & supported the most w/ scientific Topmost
evolutionary evidence Most complex
Has all the other characteristics
Clade
A branch (the line w/o the branch)
Nodes
Where branches start
Jaw Amniotic
Bipedal Lungs Hair
s membrane
Lamprey
Human ✓ ✓ ✓ ✓ ✓
Salamander ✓ ✓
Gorilla ✓ ✓ ✓ ✓
Cladogram Shark ✓ ✓
Hypothetical/Proposed phylogenetic tree Lizard ✓ ✓ ✓
Branching diagram that represents proposed phylogeny/
evolutionary history of a speices/grp
Contains traits
o Use most obvious thing one can base the
classification on
Claws/ Fea- Mammary
Jaws Lungs Fur
Nails thers glands
Eagle ✓ ✓ ✓ ✓
Tuna ✓
Baboon ✓ ✓ ✓ ✓ ✓
Salamander ✓ ✓
Hagfish
Systematics Encompassed the ff fields/studies Lizard ✓ ✓ ✓
Biodiversity Rat ✓ ✓ ✓ ✓ ✓
Taxonomy
Classification
Nomenclature
Biogeography
Evolutionary biology
Phylogenetics
TAXONOMY
Identifying, Classifying & Nomenclature (naming)
Taxonomic Order Can be photosynthetic or chemosynthetic autotrophs
Scientific name is derived from genus & species order
Homo sapiens *Prokaryotic Organisms such as archaea and bacteria were the first
o homo – genus living organisms on earth
o sapiens – species (specific to the 2 nd most
specific) Eukaryotes
1. Domain Have nucleus and complex cell parts
2. Kingdom Protista, Fungi, Pants, Animalia
3. Phylum Bacteria and Archaea merged
4. Class Complex multicellular life forms
5. Order Can photosynthesize
6. Family
7. Genus The 3-Domain System
8. Species
Carl Linnaeus
Looked for unique structures to base relation
o Back then, compared organisms based on similar
structures
Systema Naturae
Arranged organisms through Taxa (Singular:Taxon)
Binomial Nomenclature
o Taxonomic name based on the genus & species
o 2 naming system
o In order to avoid confusion, organisms have
unique scientific names
Gives clues about its relation to others
Describe the genus & species
Evolutionary Relationships among Domains
o Allow ppl to communicate when it comes to diff
types of animals/plants
Compared organisms on structures that appear similar but
actually come from completely independent origins
DOMAIN
1. Bacteria
2. Archaea
3. Eukarya (eukaryotes)
Fusion of bacteria & archaea – endosymbiotic theory
Includes the kingdoms Fungi, Plantae, Animalia & Protists.
Bacteria
Usually Microscopic single-celled organism that are marked
by tremendous metabolic innovations All organisms evolved from cells that formed over 3B years ago.
Found everywhere on Earth except extreme environments. The DNA is passed on from ancestors is described as conserved.
Single-celled prokaryotes and single chromosome
Reproduce asexually Based on similarities in ribosomal RNA, living organisms
Exhibit high metabolic diversity
Producers: Via chemosynthesis or photosynthesis Ribosomal RNA/rRNA have similar functions whether archaean or
Fix nitrogen gas: Turn into nitrate eukaryotes but then they will have differences in a bacteria in a
Decomposers eukarya & in an archaean. Difference is seen in sequences.
Includes autotrophs and heterotrophs (Cyanobacteria and
3 criteria used to differentiate the 3 domains
Stromatolites)
Archaea Differences in the nucleotide sequences of the ribosomal
RNA
“Ancient Bacteria”; the most primitive type of organisms
Lipid structures in the cell membrane
They thrive in the most extreme environments on Earth
Sensitivity to antibiotics
They are often referred to as “extremophiles”
Found in hot springs, very salty water, swamps, and the
intestines of cows
Unicellular, prokaryotic and some are autotrophic and
others heterotrophic
Superficially similar to bacteria but with unique specialized
enzymes
KINGDOM
Classification of Living Things
Domain Bacteria Archaea Eukarya
Kingdom Eubacteria Archaebacteria Protista Fungi Plantae Animalia
Cell Type Prokaryote Prokaryote Eukaryote Eukaryote Eukaryote Eukaryote
Cell walls of
Cell walls of
Cell walls w/ Cell walls w/o cellulose in some; No cell walls or
Cell Structures Cell walls of chitin cellulose;
peptidoglycan peptidoglycan Some have chloroplasts
chloroplasts
chloroplasts
Most unicellular; Most
# of Cells Unicellular Unicellular Some colonial; multicellular; Multicellular Multicellular
Some multicellular Some unicellular
Autotroph/ Autotroph/ Autotroph/
Mode of Nutrition Heterotroph Autotroph Heterotroph
Heterotroph Heterotroph Heterotroph
Amoeba, Sponges,
Streptococcus, Methanogens, Paramecium, Mushrooms, Mosses, Ferns, Worms,
Examples
Escherichia coli Halophiles Slime molds, Yeasts Flowering plants Insects, Fishes,
Giant kelp Mammals
Bacteria
Mode of Reproduction – Asexual (Binary Fission)
Single Celled: Protista, Archaea, Bacteria
Multicelled: Protista, Plants, Animals, Fungi
Heterotrophs: All kingdoms except plants
Autotrophs: All kingdoms except animals and fungi
PHYLUM
Each kingdom is subdivided into smaller, more specific
groups - phyla
Groups w/ general common features (shells, legs, spine)
Similar on morphological structures
o Depends on morphology
Birds, mammals, fish (spine), snails, limpets, lobsters
(shells)
Kingdom Animalia Kingdom Plantae
Porifera Bryophyta
Cnidaria Filicinophyta
Platyhelminthes Coniferophyta
Annelida Angiospermophyta
Mollusca
Arthropoda
CLASS
Each phylum is subdivided into smaller groups - classes
Divides group into general common features
Base of most fossil studies
Mammals – bears, mice, elephants, dolphins
ORDER
Each class is subdivided into smaller groups - orders
Groups of individuals w/ a major similar quality
Carnivora – cats, dogs, weasels, meat eaters
Class – Aves (Verterbrate w/ feathers)
Order – Passeriformes (Birds w/ adapting for perching)
FAMILY
Factors of classification
Biggest – morphology
Some – behavioral
GENUS
Each family is subdivided into smaller groups - genera
Group of species very closely related
Organisms from the genus can interbreed
Phylogenetic traits have something to do with evolutionary
relationships (closer in the cladistic = more similar/related)
Sciurus = Squirrels
SPECIES
They should interbreed
Diagnostic identification
By morphological & biochemical tests
Similarities of enzymes
Main criterion: to be able to interbreed with other
organisms of the species (fertile offspring)
Supplemented as needed by specialized tests such as
stereotyping & antibiotic inhibition patterns
