Classification of Living ThingsClassification of Living Things

Scientists estimate that there are between 3 million and 100 million species of organisms on Earth.

TaxonomistsTaxonomists--biologists who specialize in identifying and classifying life on our planet--have named approximately 1.7 million species so far.

Each year, about 13,00013,000 new species are added to the list of known organisms.

So, how do scientists classify (organize) all these millions of species?

3 Domains and 4 Kingdoms

PROKARYOTES

organisms with nono nuclear membrane

organisms withwith a nuclear membrane

2 Types of Cells

EUKARYOTES

The BigThe Big PicturePicture

The History of Life on EarthThe History of Life on Earth

Life began on Earth 3.6 billion years ago as a prokaryotic cell (single-celled organism with no nuclear membrane).

For 2.6 billion years, life was unicellular.

Multicellular eukaryotes (with nuclear membrane) evolved about 1 billion years ago.

The Earth formed 4.5 billion years ago.

Nucleolus

Nuclear membraneList the

similaritiessimilarities and differencesdifferences between EukaryotesEukaryotes and ProkaryotesProkaryotes.

Life’s History and DiversityLife’s History and Diversity

Note the close spacing of the groups plantsplants (maize), fungifungi (yeast) and animalsanimals (humans).

Line length reflects evolutionary distance.

We’ve got a lot more in common with bacteria and plants than we think!

Animals diversified in the ocean about 600 million years ago.

Plants colonized land about 440 million years ago and were followed shortly by animals.

Humans of any sort are a very recent evolutionary development (~ 7 million years ago).

Life’s HistoryLife’s History

in the ocean

3 Domains and 6 Kingdoms

The Archaea are one of two groups of prokaryotic organisms, organisms with no nuclear membrane. (Bacteria are the other group.)

Archaea are best known for living in extremely hostile environments (very hot, very acid, or very salty), but they can also be found in less extreme conditions.

Archaea are believed to be the earliest form of life on Earth. Although both archaea and bacteria are simple life-forms, archaea are very different from bacteria.

Archaea do not require sunlight for photosynthesis, as plants do, and they do not need oxygen. Archaea absorb CO2, N2, or H2S and give off methane gas as a waste product.

ArchaeaArchaea

ARCHAEAARCHAEA

A Deep Sea Hydrothermal Vent – Prime Habitat for Archaean ExtremophilesArchaean Extremophiles

video of black smoker

Hot springs in Yellowstone Park–“Hot” Spots for Archaean ExtremophilesArchaean Extremophiles

Archaea in Yellowstone

Searching for Archaea in Yellowstone’s Obsidian Pool

Prismatic Pool, Yellowstone Park

BacteriaBacteria – the Most Abundant Organisms

There are more bacteria in your mouth than there have been people living since the dawn of humans.

Bacteria (Staphylococcus aureus; yellow spheres) adhering to nasal cilia.

E. Coli bacteriaBorrelia burgdorferi, the bacterium that causes Lyme disease.

Mycoplasma hyopneumoniae

What Good Are Bacteria?What Good Are Bacteria?

Newsflash!!!

Bacteria discovered that can do photosynthesis!

Bacteria are the primary primary recyclers of recyclers of materials in the materials in the environmentenvironment, particularly nitrogennitrogen..

What Good Are Bacteria?

Bacteria are also essential for many processes we depend on – sewage treatment, cheese production, antibiotic production, and biotechnological processes like gene cloning and protein production.

Bacteria are used to produce insulininsulin and other drugs that people need.

The Domain EukaryaEukarya is divided into 4 Kingdoms:

Protista Fungi Plantae Animalia

Classifying Critters activity

PROTISTS

• Protists are eukaryotes because they all have a nucleus. • Most have mitochondria. • Many have chloroplasts with which they carry on photosynthesis. • Many are unicellular and all groups (with one exception) contain some unicellular members.

A better name for Protists would be "Eukaryotes that are neither "Eukaryotes that are neither Animals, Fungi, nor Plants"Animals, Fungi, nor Plants"..

Protists

Visit Protist Park

FUNGI

FUNGIFUNGI

Fungi sometimes look like plants, but they’re not!

Fungi can’t do photosynthesis, because they don’t have chloroplasts; they get their nutrients from the organic material they live in.

Decomposers, like mushrooms, feed on dead organic material.

Some fungi feed on living organisms, such as plants, animals and even other fungi. This causes diseases and infections in these organisms (like athlete’s foot and ringworm in humans).

Some fungi live as symbiotic partners with algae. The result: lichen (pronounced “like-n”).more lichen

Other differences from plants:• fungi don’t have roots, they have a mycelium.• fungi’s cell walls are made of chitin, not cellulose.

PLANTS

No vascular system Vascular system

Mosses, Mosses, Liverworts, Liverworts, HornwortsHornworts

Seedless Plants (reproduce by spores)

Ferns, Ferns, Horsetails, Horsetails, Club MossesClub Mosses

Seed Plants (reproduce by seeds)

Gymnosperms (“naked seeds”)

Angiosperms (flowers, seeds

enclosed in fruit)Conifers Conifers Cycads Cycads GingkoesGingkoes

Flowering PlantsFlowering Plants

ANIMALSANIMALS

Invertebrates (no backbone)

Vertebrates (backbone)

Animal ClassificationAnimal Classification

As you can see, we mammalsmammals (4000 species) are far outnumbered by the other vertebrates, or chordatesvertebrates, or chordates (38,300). And vertebratesvertebrates (42,300) are definitely outnumbered by invertebratesinvertebrates (989,700 species). The biggest categories of invertebrates: INSECTS!

3 members of the genus “Felis” (cat).

Taxonomy, or classification, enables scientists to assign a very specific name to every species, so that scientists all over the world know exactly what species is being referred to.

Kingdom

Phylum

Class

Order

Family

Genus

Species

Remember: Kids Prefer Candy Over Fresh Green Salad

Class

Kingdom:  Animalia

Phylum:   Chordata

Class:     Mammalia

Order:    Carnivora

Suborder:   Aeluroidae

Family:   Felidae

Subfamily:   Panthernae

Genus:  Panthera

Species:  Species:               Tigris   Tigris                    

Subspecies              

Panthera tigris altaica Siberian or Amur Tiger, Southeast Russia/China 

Panthera tigris tigris India  

Panthera tigris amoyensis Southern China  

Panthera tigris corbetti Indochina Panthera tigris sumatrae Sumatran Tiger, Sumatra                 

PrimatesPrimates – Our Order within the Class MammaliaMammalia

Humans:Humans:

Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Primates Family: Hominidae Genus: Homo Species: H. Sapiens

This is approximately where the last 60 million years of primate evolution has occurred.