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Sizing Up Species. What is a species?. Species a group of organisms that have a similar look and can mate to produce offspring that can also mate. How many species are there?. We Do Not Know. Sad to say, we have no “good” estimates. Estimates range from 4-40
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Species a group of organisms that have a similar look and can mate to produce offspring that can also mate
We Do Not Know. Sad to say, we have no “good” estimates. Estimates range from 4-40 (some even at 100) million.
Because: In Britain there are 22,000 species of insects, 67 of which are butterflies
And Because Globally: There are 17,500 species of butterflies
So: Assume same ratio of butterflies to insects exists globally 67 = 17,500 22,000 # insects globally
Then: This leads to an estimate of 6 million insects Globally
Described Species: 1.0-1.6 million (often quoted number: ~ 1.5 million) species described, most of which are insects, particularly beetles.
Best described regions: W. Europe and the United States-Canada
Least described regions: deep-sea; tropics Giant Isopod
Least described groups: insects, worms, fungi, protists, bacteria.
Classification: The process of putting similar things into groups
Taxonomy: The science of classifying living things.
History of Classification • 4000 B.C. Aristotle (Greek) created 1st system -TWO Groups- Plants & Animals -Animal group - anything that that lived on land, water, or in the air. -Plant group - based on their different stems
1500’s – 1700’s -Many different classification systems created -Most were complicated and confusing
1700’s Carols Linnaeus – Swedish Biologist -Established simple classification system based on structural similarities of organism -Binomial Nonmenclature - 2 Name naming system -System of groups called TAXA or TAXON -Each Taxon is a category into which related organisms are placed. -System still used today.
Moderns Day Levels of Classification KidsPlayingCatchOnFreewaysGetSquashed KingdomPhylumClassOrderFamily GenusSpecies
Kingdom: Animalia (mobile critters; have many cells; can’t make their own food) Phylum: Chordata (flexible skeletal rod with accompanying nerves) Class: Chondrichthyes (‘fish’ with a cartilaginous skeleton) Order: Lamniformes (‘Mackerel’ sharks) Family: Lamnidae (‘Mackerel’ sharks) Genus: Carcharodon (from the Greek carcharos meaning “ragged” or “pointed” and odon meaning “tooth”) Species: carcharias (Greek for “shark”)
Binomial Nonmenclature “Two-Name Naming” Is a system of Scientific Naming using: TWO NAMES FOR EVERY ORGANISM THE GENUS AND THE SPECIES NAME
The system follows certain rules 1. The scientific name must be Greek or Latin 2. The 1st name is always the Genus and the 2nd is always the species (Latin for “identifier”) Panthera tigris
3. The Genus is always capitalized, species is always lower case. Name should be underlined or written in italics. Genus can be abbreviated. Ex: Tyrannosaurus rex Tyrannosaurus rex T. rex or T. rex
4. Two different organisms MUST not be assigned the same scientific name and one particular organism will have ONLY one scientific name. Ex: Cougar….Mt Lion….Puma Felix concolor
Dog ښڝڞ perro canis Sobaka chien Advantages of using a universal taxonomic system: Organization- for better understanding Common Language- for better communication among scientists
Have nucleus Prokaryotes: Lack a nucleus
Kingdom Monera Characteristics: 1. Prokaryotes (no nucleus) 2. Heterotrophic & Autotrophic 3. Aquatic, terrestrial & in the air 4. Asexual & sexual 5. Oldest kingdom (3.5 BYA) Ex: Bacteria
Kingdom Protista Characteristics: 1. Eukaryotes (nucleus) 2. Heterotrophic and Autotrophic 3. Mostly aquatic 4. Mostly sexual 5. Mobile and Immobile Ex: Paramecium, Diatoms Slime mold
Kingdom Fungi Characteristics: 1. Eukaryote 2. Heterotrophic 3. Single & Multicellular 4. Mostly terrestrial 5. Asexual & Sexual 6. Nonmobile Ex: Mushroom, mold, yeast
Kingdom Plantae Characteristics: 1. Eukaryote 2. Multicellular 3. Autotrophic 4. Mostly terrestrial 5. Asexual & Sexual 6. Nonmobile Ex: Mosses, ferns, conifers flowering plants
Kingdom Animalia Characteristics: 1. Eukaryote 2. Heterotrophic 3. Multicellular 4. Terrestrial & aquatic 5. Sexual 6. Mobile Ex: Sponges, jellyfish, mollusks, fish, birds mammals, reptiles, insects
A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish.
Keys consist of a series of choices that lead the user to the correct name of a given item.
"Dichotomous" means "divided into two parts". Therefore, dichotomous keys always give two choices in each step.