The science of classifying organisms Section 9.1 in your textbooks Taxonomy The science of classifying organisms Section 9.1 in your textbooks

Key Terms Taxonomy Binomial nomenclature Species Genus Taxa Phylogeny Dichotomous key

Why do we need to classify? Imagine a grocery store… How do you know where to find the fruits? The vegetables? The meat? The frozen food? How is the store organized? Think about your computer… How are the files organized? Are all of your pictures and music and documents in the same folder?

When you have a lot of information, it is best to organize and group items so that you can find them easier or easily see their relationship to other items. ….. This is why we classify!

Classifying Organisms About 1.5 million species have been named Estimated to be millions of species yet to be discovered! Taxonomy: groups similar organisms together & assigns each one a name

How do biologists NAME organisms? The “common names” people use are often misleading or confusing Organisms may have more than one common name (and different names in different languages!) or their common name may cause you to think of another organism…

Wolf spider Spider monkey Horse Seahorse Sea monkey

Gray Wolf Black Bear

Firefly or Lightning bug Larch or Tamarack Poplar or aspen Cottonmouth or Water moccasin

Mud puppy Panda Bear In Chinese: Da xiong mao Big bear cat ??!! Red panda

Scientific Names In order to communicate effectively, scientists must have a consistent naming protocol All organisms have only 1 scientific name Usually Latin or Greek Developed by Carl Linnaeus (Swedish botanist, 1707-1778) Naming and classifying organisms are both part of taxonomy

Binomial Nomenclature 2-word naming system Written in italics or underlined 1st word is Capitalized (Genus) 2nd word is lowercase (species) Can be shortened to: G. species Scientific names are usually based on some characteristic of the organism and show similarities in anatomy, or evolutionary history.

Members of the same genus are closely related Only members of the same species can interbreed (under natural conditions) Some hybrids do occur under unnatural conditions e.g. Ligers are crosses between tigers and lions, Zeedonks are crosses between zebras and donkeys!

Wolf spider Hogna lenta Spider monkey Ateles arachnoides Horse: Equus ferus Seahorse: Hippocampus sp. Sea monkey: Artemia sp.

Gray Wolf: Canis lupus Black Bear: Ursus americanus

Firefly or Lightning bug Photinus pyralis Larch or Tamarack Larix decidua Cottonmouth or Water moccasin Agkistrodon piscivorus Poplar or aspen Populus tremula

Mud puppy: Necturus maculosus Panda Bear In Chinese: Da xiong mao Big bear cat ??!! Ailuropoda melanoleuca Red panda: Ailurus fulgens

Linnaeus also created a system that we use today that places organisms into a few large groups (KINGDOMS) and then those groups are divided into smaller groups (taxa). KINGDOM PHYLUM CLASS ORDER FAMILY GENUS SPECIES Each group gets smaller and more specific, just like when you group your files into folders on the computer.

King Philip Came Over For Great Soup To help you remember… King Philip Came Over For Great Soup

Human Cougar Tiger Pintail Duck Kingdom Animalia Phylum Chordata Class Mammalia Aves Order Primate Carnivora Anseriformes Family Homindae Felidae Anatidae Genus Homo Felis Panthera Anas Species sapiens concolor tigris acuta

Primitive Classification Aristotle said that humans are the most complex organisms, so they should be at the top of the “ladder” Scala naturae Simpler organisms are beneath humans

(less) Primitive Classification Linnaeus grouped species mainly on visible similarities and differences The more features organisms have in common, the more closely they are related.

Modern Evolutionary Classification Today, taxonomists group organisms into categories that represent lines of evolutionary descent (phylogeny) Evolutionary relationships among a group of organisms can be shown on a phylogenetic tree or a cladogram

Cladogram

Similarities in DNA and RNA DNA & RNA is similar across all life forms Genes of many organisms show important similarities at the molecular level DNA shows evolutionary relationships & helps to classify organisms

The Six Kingdoms Kingdom # of Cells Energy Cell Type Cell Wall Habitat Examples Eubacteria Unicellular Autotrophic & heterotrophic Prokaryote Often present Everywhere Bacteria, cyanobacteria, E. coli Archaebacteria Autotrophic & chemotrophic Present Extreme environments (salt lakes, hot springs, animals’ guts) Methanogens, extreme thermophiles, extreme halophiles Protista Mostly unicellular, some multicellular Eukaryote Absent Aquatic Algae, amoebas, paramecium, protozoa Fungi Mostly multicellular Heterotrophic Terrestrial Mushrooms, yeast, mould Plantae Multicellular Autotrophic Mostly terrestrial Mosses, ferns, trees, grass, flowers Animalia Aquatic & terrestrial Sponges, worms, lobsters, starfish, humans

Dichotomous Keys A dichotomous key is a written set of choices that leads to the name of an organism. 2 choices at each level Scientists use these to identify already named unknown organisms

Hypothetical Dichotomous Key

Try it… Classify each of the whales on page 332 using the dichotomous key on page 333. Create a dichotomous key based on hypothetical species names for the insects on page 333.

Activity 9.1.1 Figure 7: killer whale (Orcinus orca) Figure 8: humpback whale (Megaptera novaeangline) Figure 9: beluga (Delphinapterus leucas) Figure 10: narwhal (Mondon monoceros) Figure 11: sperm whale (Physeter macrocephalus) Figure 12: blue whale (Balaenoptera musculus) Figure 13: bowhead whale (Balaena mysticetus)

Insect Key - example General Insects a) Has wings b) No wings Go to 2 Ant 2. a) Hairy body b) No hair on body Bee Go to 3 3. a) Large, colourful wings b) Hard, shell-like wings Butterfly Go to 4 4. a) Green colour b) Black & red colour Green beetle Black & red beetle