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Leucaena leucocephala Lead tree

ClassificationWhat we use to classify organisms

Naming - Binomial Nomenclature Two part name (Genus, species)

Organizing - Hierarchical Classification Seven Taxonomic Catagories

Taxonomic categories Kingdom King Phylum Philip Class Came Order Over Family For Genus Good Species Soup

Systematics Study of the evolution of biological diversity

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Carolus von Linnaeus(1707-1778)

Swedish scientist who laid the foundation for

modern taxonomy

Binomial Nomenclature

Carolus von Linnaeus

Two-word naming system Genus

Noun, Capitalized, Underlined or Italicized

Species Descriptive, Lower Case,

Underlined or Italicized

But why LATIN?

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Kingdoms and Domains

Bacteria Archaea Eukarya

Bacteria Archaea Protista Plantae Fungi Animalia

Monera Protista Plantae Fungi Animalia

The three-domain system

The six-kingdom system

The traditional five-kingdom system (LAME!)

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More on Kingdoms and Domains

Bacteria (true bacteria) most common

Archaebacteria (ancient bacteria) EXTREMES! Ancestors of Eukaryotes!

Eucaryota Protista (Protoctista)

Not Animalia(no blastula) Not Plantae (embryo within maternal tissue) Not Fungi (no spores) and have cilia and flagella Not Monerans (have nucleated cell, live in water, formed

from symbiogenesis

Fungi, Plantae and Animalia…..

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Three Domains (Superkingdoms) Of Living Organisms

  I.  Bacteria (19): Most of the Known Prokaryotes

Division (Phylum) Proteobacteria: N-Fixing BacteriaDivision (Phylum) Cyanobacteria: Blue-Green BacteriaDivision (Phylum) Eubacteria: True Gram Posive BacteriaDivision (Phylum) Spirochetes: Spiral BacteriaDivision (Phylum) Chlamydiae: Intracellular Parasites

 II.  Archaea (16): Prokaryotes of Extreme Environments Kingdom Crenarchaeota: Thermophiles

Kingdom Euryarchaeota: Methanogens & HalophilesKingdom Korarchaeota: Some Hot Springs Microbes

III.  Eukarya (35): Eukaryotic Cells Kingdom Protista (Protoctista)

Kingdom Fungi Kingdom Plantae Kingdom Animalia

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Systematics:Evolutionary Classification of Organisms

Systematics is the study of the evolution of biological diversity, and combines data from the following areas.

Fossil record (we know about these) Comparative homologies (including vestigial

structures) Cladistics Comparative sequencing of DNA/RNA among

organisms Molecular clocks

These categories are where we derive evidence for evolution!

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Cladistics

Uses evolutionary relationships between groups to construct family tree using Principle of Parsimony

Relationships shown by analyzing ancestral (primitive) and derived characters.

Primitive: common to all members of the group

Doesn’t help with relationships

Derived: appear in some members of the group.

Clues to evolutionary relationships

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Comparative Sequencing of DNA/RNA

First: Compared protein similarities (pre 1970)

Then: DNA hybridization Measures similarities of DNA of

different species Suggested more similarities between chimp

and human rather than orangutan or gorilla

Now: DNA sequencing Done since the 80s

Can’t answer all the questions. Need other lines of evidence as well.

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Molecular Clocks

Assumption: some evolutionary changes

occur in a reliable clock-like fashion.

Over the course of millions of years, mutations may build up in any given stretch of DNA at a reliable rate.

RESULT: When a stretch of DNA can be used as a molecular clock, it becomes a powerful tool for estimating the dates of lineage-splitting events.

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Taxonomic Diagrams

Mammals Turtles Lizards and Snakes

Crocodiles Birds Mammals Turtles Lizards and Snakes

Crocodiles Birds

CladogramPhylogeneticTree

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Phylogeny

Phylogenies trace patterns of shared ancestry between lineages

Similarly, each lineage has common ancestors.

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Clades and Cladograms

Grouping that includes a common ancestor and all the descendents (living and extinct) of that ancestor.

Using a phylogeny, it is easy to tell if a group of lineages forms a clade.

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Nested Hierarchies

Groups of related organisms share sets of similar characteristics

The number of shared traits increases with relatedness.

Snakes and lizards more closely related to one another than to the other animals represented.

However, at a more inclusive level, snakes, lizards, birds, crocodiles, whales, camels, chimpanzees and humans all share some common traits since they have a common ancestor.

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Viruses

Not in any kingdom

No membrane-bound organelles

No ribosomes (organelle site of protein synthesis),

No cytoplasm (living contents of a cell),

No source of energy production of their own.

No self-maintenance metabolic reactions of living systems. Viruses lack cellular respiration, ATP-production, gas exchange, etc.

Do reproduce, but at the expense of the host cell. Only capable of reproduction within living cells.