Introduction to Unit 2: Diversity of Living Things

When you see this pencil…copy it down!

We use various forms of classification in our everyday activities. We organize and group things to avoid confusion among objects, ideas, and events.

What would life be like without classification systems?

What would it be like trying to find an article in the newspaper’s classified section without the benefit of categories? Or using a phonebook without an alphabetical listing?

Organization in Our Lives

Organization of LifeJust like we organize and categorize

things to make it easier to identify….and our lives easier, we also organize living organisms.

The science of classifying organisms is taxonomy.

Taxonomy has two key purposes:◦To identify organisms◦Represent relationships among them.

All organisms are organized into categories called taxons.

Names

The names of some organisms are really inaccurate as a scientific label Examples:

◦Inaccurate name – “frog”◦More precise names are

◦ tree frog◦ grass frog◦ bullfrog

Names…

Inaccurate name – “worm”◦More precise name would be

◦Earthworm◦Roundworm◦Tapeworm

Names…

Inaccurate name – “dog”◦More precise name would be

Collie German shepherd Rottweiler

Aristotle (384-322 BC)◦Divided organisms into two groups◦Classified plants on the basis of structure and

size (herbs, shrubs, trees)◦Classified animals based on where they lived

(air, land, sea)

Decided that organisms should be named as well as classified

Referred to organisms with the same characteristics and same kind of parents as belonging to the same species

In the last part of the 17th century, Ray described and named over 18000 species of plants.

John Ray (1625-1705)

Charles Linné (1707-1778)Swedish botanist who made the greatest contribution to taxonomy!

Decided that organisms should be grouped according to similarities in body structure

Introduced a two-part system to name and classify organisms: binomial nomenclature◦Each organism is given a two-word Latin name

(or in a Latin style), as Latin is not commonly used today.

Binomial Nomenclature

“Binomial” means 2 names“Nomenclature” means a set or system of

names or terms.Example: Humans

Homo sapiens or Homo sapiens

The first word is the genus to which an

organism belongs. It is always capitalized.

The second word is the species name (more

specific) is not capitalized.

Why do we use scientific names?Scientific names are used in biology instead of common names because:1. Every living thing has a different

scientific name.2. Scientific names seldom change.3. Scientific names are written in the same

language around the world.

Examples of Binomial Nomenclature

Now… Complete Scientific Names Activity

Scientific names of organisms usually derive from either Latin or Greek words and very often the word describes some feature of the organism – its appearance, how it moves, what it eats, where it lives, etc.

Carl Linnaeus (1707-1778)

•Often called the “Father of Taxonomy”.

•His system for naming, ranking, and classifying organisms is still in wide use today.

•Linnaeus divided all living things into Kingdoms

•In his day, Linnaeus know of only two kingdoms: plants and animals.

http://www.ucmp.berkeley.edu/history/images/linnaeus.jpg

KingdomsToday we have six (6) Kingdoms:

◦Eubacteria◦Archaebacteria◦Protista◦Fungi◦Plantae◦Animalia

Today’s ClassificationClassifying organisms provides order and a logical

way of naming things.

Classifications are based on:

◦ Appearance and structure◦ Example: number of limbs, body covering, number of heart chambers, etc.

◦ Development and biochemistry◦ Cell type (prokaryote, eukaryote, similar organic compounds – such as

composition of blood, chlorophyll).

◦ Likely common ancestry◦ The greater the similarity of DNA (genes), the more closely related the

organisms are.

Today’s Classifcation System…

Today, the classification system we use to organize living organism doesn’t only include species, genus, and kingdom, but four other levels too…

7 Levels of TaxonomyThere are seven levels of taxonomy:

Kingdom – largest grouping of living thingsPhylum – largest grouping within a kingdomClass – largest grouping within a phylumOrder – largest grouping within a classFamily – largest grouping within an orderGenus – largest grouping within a familySpecies – largest grouping within a genus

Memory Aid!

To aid in your memory of the 7 levels, use one of the following sayings:

Keep People Clear Of Fast Great Sharks

King Phillip Came Over For Great Spaghetti

This diagram shows how each level of taxonomy is directly related to the level before it. • Kingdoms are made up of

various phylum.• Phylum are made up of various

classes.• Orders are made up of various

classes. • Family’s are made up of various

orders. • Genus and Specie are the

scientific name.

There are six Kingdoms – an organism will fall into one of the six kingdoms.

Example: Mountain Lion The Mountain Lion is an animal, therefore it falls

into the Animal Kingdom.

There are 9 major phyla groups in the Animal Kingdom. Each phyla contains specific details related to an organism.

The Mountain Lion belongs to the Chordata Phylum because this phyla group is characterized by its organisms having a backbone / spine.

There are six main classes of Animals in this world: mammals, birds, fishes, reptiles, amphibians, and invertebrates.

Each class has specific characteristics. The Mountain Lion belongs to the Mammal Class

because it has fur and produces milk.

http://sciencecastle.com/sc/index.php/animalspecies/showclasses

If we were to look at Mammals, there are 19 groups of ‘orders’ that they could possibly fall into. Each with specific characteristics.

Which order does the mountain lion belong to?

http://www.cftech.com/BrainBank/OTHERREFERENCE/ANIMALWORLD/OrderMammals.html

There are many ‘family’ groups belonging to the Carnivora class.

The Mountain Lion belongs to the “Felidae” family because this family includes all cats.

Genus is the first part of the organisms scientific name. It’s genus is from latin/greek.

The Mountain Lion’s genus is “Puma”

Specie – is the second part of the organism’s scientific name.

Based on unique characteristics of the Mountain Lion it falls into the species “concolor”.

Here is what we found out:The Mountain Lion belongs to the:

◦The Animal Kingdom◦The Phyla “Chordata” ◦The Class “Mammal”◦The Order “Carnivora”◦The Family “Felidae” ◦The Genus “Puma”◦The Specie “concolor”

Conclusion & Helpful Tip!All together these seven levels helped scientists

(and us today) to identify the specific scientific name given to the mountain lion.

We were able to find out all kinds of other information about the mountain lion along the way too (from physical appearance, structure, physiology, to diet, etc.)

Each level is very important in the classification of an organism…you can’t skip a level!

Think of each level as a step that you must take the organism through in order to properly find its name (its scientific name). You could also look at it from the point of trying to find the organisms home – its exact location as to where it belongs!

Classification…

The more classification groups that living organisms share (groups such as kingdom, phyla, class, etc.) the more closely related they are.

Classification Example

Here are two examples of classifying living organisms – humans and killer whales. Each of the 7 levels of taxonomy are identified for each organism. Are we closely related to the Killer Whale? Explain.

Dichotomous Keys

Dichotomous keys are classification manuals that are used to help biologists determine the scientific name of an organism.

To use a key, you are given a series of options where you have to make one of two choices about your organism until ultimately you end up with its identification.

SEE PAGE 33O IN TEXTBOOK!

Key example:

This is one type of dichotomous key in a ‘spider’ format as it kind of looks like a spider.

Your Activities for TodayComplete:

◦Classification Worksheet

Whale Key Activity◦‘Activity 9.1.1. – Using a Classification Key’

(pages 332-333)◦ In this activity, you will identify various species of

whales using a dichotomous key.

The Fox & the HareAbout every 10 years, a dramatic phenomenon plays out in Canada’s Boreal Forests. Populations of snowshoe hares and their predators go through a cycle of boom and bust. What do you think happens when fox populations are low?How does this eventually impact the fox populations?The fox is very efficient at killing hares, how does this effect the hare population?What is now happening to the fox’s food source? How does this impact the fox population?ALL LIVING THINGS EFFECT EACH OTHER! THIS IS JUST ONE EXAMPLE!