Diversity of Life

Why Classify?

There are 1.5 million different types of living organisms

We need to have a way of identifying them

This is called Taxonomy

Taxonomy is defined as a discipline of classifying organisms and assigning each one a universally accepted name

Why is this important?

This animal is called a cougar, a puma, a panther, or a mountain lion

And these are only its English names!

Past Classification Systems

Ancient Man: simple classification, non-edible/edible, big/small, dangerous/safe

Aristotle: first organized system, plants, animals (split into land, water, or air creatures)

During the ‘Age of Discovery’ (1400s-1600s) people were bringing new plants and animals back to Europe and they needed names

Carolus Linnaeus: a Swedish botanist developed a two word naming system called Binomial Nomenclature

1960s: As time passed and new biochemical techniques and electron microscopes were developed we were able to see more differences between species and a new proposal for a multi-Kingdom system emerged

R.H. Whittaker: first proposed the Five Kingdom classification system

Today we still use the basic system that Linnaeus developed

-Species: group of similar organisms that can breed and produce fertile

offspring

e.g. Grizzly BearUrsus arctos

Classification System

Genus: group of closely related species

e.g. Genus Ursus contains 5 other types of bears

Ursus arctos, Ursus maritimus

Family: group of genera that share many characteristics

e.g. Ailuropoda melanoleuca, Ursus maritimus and Ursus arctos are in the same family: Ursidae

Order: group of similar families

e.g. bears, dogs and cats are all part of the order Carnivora

Class: group of similar orders

e.g. order Carnivora is a part of class Mammalia

Phylum: group of closely related classes

e.g. class Mammalia is grouped with Aves, Reptilia and Amphibia into phyla Chordata

Kingdom: large taxonomic group, consisting of closely related phyla

E.g. Kingdom Animalia

So to Re-cap We Have...Kingdom

Phylum

Class

Order

Family

Genus

Species

It is very important to put these in the correct order so sometimes people use acronyms to remember the correct order

e.g King Philip Came Over For Green Soup, or

e.g. Kings Play Chess On Funny Glass Stools

When Linaeus started classifying he split organisms into 2 kingdoms: Plantae and Animalia

Then in the late 1800s we added in another Kingdom: Protista, Plantae and Animalia

Now that we have a classification system, which category do all these different animals fit into?

We currently use a classification system that has 5 different Kingdoms

Monera

Protista

Fungi

Plantae

Animalia

But...

Some biologists feel that in Kingdom Monera there are two distinct groups represented and then Monera is then split into two different Kingdoms called: Eubacteria and Archaebacteria

Binomial Nomenclature

Classification system in which each species is assigned a two part scientific name

Names are in Latin

Genus is first and capitalized

species is second and lower case

both names are underlined OR are in italics

Rules of Binomial Nomenclature

Felis catus

Spodromantis viridis

Homo sapiens

How do we decide which organism goes in which Kingdom, Class, Species

Structural features are still the main source of evidence used to compare organisms.

But we also use:

Biochemistry: compare DNA, proteins, etc. DNA is 98% the same between Humans and Chimps

Cytological Information: analyzing cell structures, cell organelles

Embryological Information: similarities between embryo development

Behaviour Differences: some behaviour used to differentiate species

Fossil Evidence: provide links with past species

Kingdom Monera1. sub-kingdom- Archaebacteria

unicellular, ancient bacteria

prokaryotic (no nucleus)

cell wall

lives in harsh environments

does not have peptidoglycan

obtains energy as autotroph and/or heterotroph

2. sub-kingdom- Eubacteria (true bacteria)

unicellular, found in colonies

prokaryotic

has cell wall

has peptidoglycan

obtain energy as autotroph and/or heterotroph

e.g. disease producing, cyanobacteria, Escherichia coli

unicellular, colonial and multicellular

eukaryotic (have a nucleus)

they are ‘animal’ like, ‘plant or fungi’ like or ‘bacteria’ like

they obtain energy as an autotroph and heterotroph

e.g. amoeba, paramecium

Kingdom Protista

Kingdom Fungiunicellular and multicellular

eukaryotic cells

have cell walls like plants, made of chitin

reproduce by spores

all fungi are parasites or decompose

obtain energy by digesting and absorbing whatever is in the ground

e.g. mushrooms, mold

Kingdom Plantae

multicellular

sessile

cell wall made of cellulose

leaves are specialized

obtain energy from sunlight through photosynthesis

e.g. roses, ferns, spruce trees

Kingdom Animalia

multicellular and motile

no cell walls

high level of organ and organ system organization

sexual reproduction

obtain energy by eating other organisms

e.g. mammals, insects

Dichotomous Key

a device than can be used to identify an unknown organism

it consists of a variety of two part statements that describe the characteristics of organisms

Dichotomous Key for pens and pencils

Or it could look like this.

ReviewTaxonomy

Linnaeus

Kingdom, Phyla, Class, Order, Family, Genus, Species

5/6 Kingdoms

Binomial Nomenclature

Structure, biochemistry, cytological info, embryological info, behaviour, fossil

Kingdoms

Dichotomous Key