Classification of Living Things Scientists estimate that there are between 3 million and 100 million species of organisms on Earth. Taxonomists Taxonomists--biologists who specialize in identifying and classifying life on our planet--have named approximately 1.7 million species so far. 13,000 Each year, about 13,000 new species are added to the list of known organisms.new species So, how do scientists classify (organize) all these millions of species?

3 Domains and 4 KingdomsDomains and 4 Kingdoms PROKARYOTES no organisms with no nuclear membrane with organisms with a nuclear membrane 2 Types of Cells EUKARYOTES

The Big The Big Picture Picture

The 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 membrane similarities differences Eukaryotes Prokaryotes List the similarities and differences between Eukaryotes and Prokaryotes.

Life’s History and Diversity plantsfungi animals Note the close spacing of the groups plants (maize), fungi (yeast) and animals (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 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 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 CO 2, N 2, or H 2 S and give off methane gas as a waste product.ArchaeaARCHAEA

Archaean Extremophiles A Deep Sea Hydrothermal Vent – Prime Habitat for Archaean ExtremophilesHydrothermal Vent video of black smoker

Archaean Extremophiles Hot springs in Yellowstone Park–“Hot” Spots for Archaean Extremophiles ArchaeaArchaea in Yellowstone Searching for Archaea in Yellowstone’s Obsidian Pool Prismatic Pool, Yellowstone Park

Bacteria Bacteria – the Most Abundant Organisms There are more bacteria in your mouth than there have been people living since the dawn of humans.bacteria Bacteria (Staphylococcus aureus; yellow spheres) adhering to nasal cilia. E. Coli bacteria Borrelia burgdorferi, the bacterium that causes Lyme disease. Mycoplasma hyopneumoniae

What Good Are Bacteria? Newsflash!!! Bacteria discovered that can do photosynthesis! primary recyclers of materials in the environment nitrogen. Bacteria are the primary recyclers of materials in the environment, particularly nitrogen.

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.

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

Eukarya The Domain Eukarya is divided into 4 Kingdoms: ProtistaFungiPlantaeAnimalia 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. "Eukaryotes that are neither Animals, Fungi, nor Plants". A better name for Protists would be "Eukaryotes that are neither Animals, Fungi, nor Plants". Protists Visit Protist Park

FUNGI FUNGI 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 lichenmore 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 systemVascular system Mosses, Liverworts, Hornworts Seedless Plants (reproduce by spores) Ferns, Horsetails, Club Mosses Seed Plants (reproduce by seeds) Gymnosperms Gymnosperms (“naked seeds”) Angiosperms Angiosperms (flowers, seeds enclosed in fruit) Conifers Cycads Gingkoes Flowering Plants

ANIMALS Invertebrates Invertebrates (no backbone) Vertebrates Vertebrates (backbone)

Animal Classification

mammals vertebrates, or chordates vertebrates invertebrates As you can see, we mammals (4000 species) are far outnumbered by the other vertebrates, or chordates (38,300). And vertebrates (42,300) are definitely outnumbered by invertebrates (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: Tigris Species: 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

Primates Mammalia Primates – Our Order within the Class Mammalia 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.