1. Classifying living things
Scientists develop system for classifying living things.
Scientists classify millions of species
400 years ago organisms were classified on their appearance and behavior
The problem with this is scientists have realized that appearances can suggest false connections.
Many things helped change these classifications
Observing
Collecting samples
The microscope

2. Classifying living things
Classification and Taxonomy
Classification is the process of arranging organisms into groups based on similarities
Taxonomy is the science of naming and classifying organisms.
A good system allows one to organize a large amount of information
so it is easy to find and understand.

3. Classifying living things
Using Classification
Similarities and differences among species are used
Sometimes easy to see like fur, feathers, or scales
Others more detailed and require DNA
Taxonomists study Biological relationships
The Greek word, taxis means arrangement.
Taxonomists are scientists who classify and name organisms based on their similarities and differences.

4. Classifying living things
A Taxon is a group of organisms that share certain traits.
Taxons can be broad like animals and plants
More specific like cats and roses.
Taxonomists try to discover how one species evolved as compared with another species.
Species sharing an ancestor are group together.

5. Classifying living things
To determine how to classify, scientists compare a variety of characteristics or traits
A trait is a characteristic or behavior that can be used to tell two species apart.
IF two organisms share a trait, taxonomists try to determine if they share the trait because they share an ancestor.

6. Classifying living things
Physical Evidence
All physical evidence helps scientists see that all living organisms are related by evolution
Primary tools used
Color
Size
Weight
How group of organisms obtain energy.
The internal structure
And outward appearance
Comparing skeletons, and fossilized parts

7. Classifying living things
Genetic Evidence
In the mid 1950’s DNA helped further classify
Genetic evidence usually support physical evidence, but not always
Best example is the red panda and Panda bear
Both ate bamboo,
Both look alike except for size
DNA proved that the red panda is more related to the raccoon family
Pandas more closely to bears

8. Classifying living things
Biologists use seven levels of classification
Carolus Linnaeus developed both a naming system and how to organize them.
Used appearance to group
This was called the binomial nomenclature.
Binomial means two names
Nomenclature means list of names
Most of these names are Latin

9. Classifying living things
Using scientific names
He used both a genus and species.
Certain rules for scientific names must be followed
First letter of the genus (which comes first) is capitalized
Species’ first letter is lowercase
Both written in italics
These two names are part of a classification system that contains several larger parts.

10. BINOMIAL NOMENCLATURE
Uses two names
A GENUS and A SPECIES
Haliaeetus leucocephalus
Genus is always CAPITALIZED
Species is always lower case
BOTH ARE IN ITALICS OR UNDERLINED
Just like us, each animal was given 2 names

11. Latin Binomials Canis latrans Canis lupis Canis familiaris
Coyote
Canis lupis
Timber Wolf
Canis familiaris
Domesticated Dog
Panthera leo
Lion
Panthera onca
Jaguar

12. Classifying living things
Classified into 7 groups
Each group gets narrower or specific then that last.
Kingdom (most general) (Animalia- the animals)
Phylum (Chordata- animals with a backbone)
Class ( Mammalia- mammals or furry animals that nurse their young.)

13. Classifying living things
Order ( Carnivora- carnivores, or animals that kill and each other animals)
Family (Felidae- cat family)
Genus( Felis housecats, cougars, and many others
Species (catus- all housecats regardless of breed)
Scientists can compare very broad categories,
As they go down the classification level, you get more specific, eliminating organism that are not longer similar.

14. Classifying living things
Dichotomous keys and field guides help identify
A series of questions that can be answered in only 2 ways
Your answer to each question leads to another question with only 2 choices
The questions gradually narrow down the list of possible organisms.
Field guides also help identify based on physical characteristics.

15. Classifying living things
Classification systems change as more is learned.
Taxonomy changes as discoveries are made
First there were 2 groups
Plants
Green
Non-moving
Animals

16. Classifying living things
Three Domains
Grouping before placing organism into Kingdoms
Cells containing a nucleus are called eukaryotic cells
Cells with no nucleus called prokaryotic cells
The domain Bacteria and Archae include ONLY prokaryotic cells
Eukarya contain organisms with eukaryotic.

17. Classifying living things
Bacteria- class smaller then Eukarya and have no nucleus
Archaea- Cells have a distinctive chemistry and can survive extreme environments.
Eukarya- larger and contain more complex structures

18. Classifying living things
Six Kingdoms
After domains, all organisms fall into one of six kingdoms
Plantae (includes plants, trees, grass, and moss)
Animalia (animals from lions to bugs to Multicellular microbes)
Protista ( organisms that don’t fit easily into animals, plant, or fungi. Either unicellular or have a simple Multicellular structure)

19. Classifying living things
Fungi (mushrooms, molds and yeasts)
Archaea ( organisms that are similar to bacteria but have a cell structure so different they must fit in own kingdom)
Bacteria (unicellular with no nucleus)
Changed around 1990 from 5 kingdoms.
Chemical differences between cells
Protista should be arranged into smaller kingdoms because of the many differences among its species.

20. Classifying living things
Two most familiar kingdoms are plants and animals.
Plantae
250,000 plant species known on Earth.
Tiny moss to giant kelp
All plants multicellular
All plants can make their own food via photosynthesis
Can not move from place to place
Can turn to face the sun or light
Grow upward

21. Classifying living things
Animalia
Already a million species in the kingdom
More then 90 percent are insects
All animals get energy from other organisms
Most have some type of mouth and
A nervous system
Has no cell wall like plants

22. Classifying living things
Other organisms in remaining 4 kingdoms
Protista
Has a wide variety of organism
Most unicellular
Have large complex cells with true nucleus (eukaryote)
Some eat other organisms
Some can photosynthesize
Do not have specialized cells like plants, animals, or fungi
Most live in fresh or salt water
Euglena sp.

23. Classifying living things
Some organisms, like seaweed are also classified as Protista
Fungi
Composed of molds, yeasts, mushrooms
Take in nutrients from their surrounding
Remain rooted in one place
Many fungi act as decomposers
Don’t photosynthesize

24. Classifying living things
Archaea
Mid 1990’s changed classification of bacteria
Do not have a nuclei
But cell structure is different from that of bacteria
Live in water environments
Live in extreme environments like boiling mud near geysers, Hot vents, bottom of oceans, salt ponds, deep in sand

25. Classifying living things
Bacteria
Live just about everywhere.
Most are helpful
Some harmful
All unicellular
Have small cells without a nucleus
Have a cell wall but not the same as plants