Transcript Welcome! [msedbiology.weebly.com]

The Origin of Life
• Life originated 3.5-4.0
billion years ago!
What came first:
prokaryotic cells or
eukaryotic cells?
Prokaryotes
• Prokaryotes dominated life
on Earth from 3.5-2.0 bya!
– The 1st actual cells
3.5 billion year old fossil of
bacteria
Modern bacteria
Chains of unicellular
cyanobacteria
The Origin of Eukaryotic Cells
Bacteria were the starting point for all the life we have today!
How many species exist on Earth?
• We don’t know an exact number 
– MILLIONS
• More still waiting to be discovered!
How do we keep track of all of them?
Classifying Organisms
Devil Cat
Ghost Cat
Mountain Lion
Screaming Cat
Puma
Florida Panther
Cougar
All the same species!
• There are at least 50 different
names for the species of cat
shown before.
– Different places have different
names.
• Scientific name: Felis concolar
– Why is it important to have
scientific names?
Scientific Names
• Give species an “official” name
• Come from “dead” languages – Latin or Greek
• We get the names from the way the organisms are
classified.
Solenopsis invicta
Taxonomy
Classifying Living Organisms
Taxonomy
• The science of classifying
organisms
– Show how organisms are
related
– Provides a universal system
for identifying organisms
– Provides scientific names
We use the Linnaean system
for classifying organisms.
A good way to remember…
King
Phillip
Came
Over
For
Good
Soup
What is the order of the Linnaean classification
system?
A.
B.
C.
D.
Kingdom, Phylum, Genus, Class, Order, Family, Species
Kingdom, Family, Phylum, Genus, Order, Class, Species
Kingdom, Phylum, Class, Genus, Order, Family, Species
Kingdom, Phylum, Class, Order, Family, Genus, Species
King Phillip Came Over For Good Soup
Kingdom, Phylum, Class, Order, Family, Genus, Species
Linnaean Classification
• System for classifying
organisms by hierarchy goes from broad to specific!
All living species can be broken
down into 6 kingdoms:
1.
2.
3.
4.
5.
6.
Animalia
Plantae
Fungi
Protista
Eubacteria
Archaebacteria
Each of these kingdoms can be
broken down into phylums!
Animalia
Plantae
Fungi
All Living
Species
Protista
Eubacteria
Archaebacteria
Human Linnaean
Classification
Notice how we
went from broad
categories to
specific categories!
Kingdom Animalia
contains many species!
Some animals have a
backbone, some don’t.
Phylum Chordata (backbone)
includes several mammals.
Some mammals are carnivores.
Several carnivorous mammals are
bears.
Some bears are more closely related
than others…
We’ve narrowed it down to a specific
species!
Binomial Nomenclature
• Formal system for naming
species
– Latin or Greek
– Italicized
– Genus species
Turdus migratorius,
or American Robin 
What genus does the American Robin belong to?
A.
B.
C.
D.
American
Robin
Turdus
Migratorius
Turdus!
Remember that species get their
scientific names from their
classification – Genus species
Turdus migratorius 
Which species are more closely related?
A. Panda & Polar Bear
B. Polar Bear & Grizzly Bear
C. Grizzly Bear & Panda
Polar & Grizzly Bear – they
belong to the same genus!
Which of the following is true?
A. All animals are chordates.
B. All felines belong to the
genus Panthera.
C. All chordates are
mammals.
D. All felines are carnivores.
Which category in the Linnaean System is the
most specific?
A.
B.
C.
D.
Phylum
Family
Class
Genus
Genus!
Broad
copyright cmassengale
Specific
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