Diversity & Diversity & ClassificationClassification

Objective AObjective AStudents will define the Students will define the

criteria used for classifying criteria used for classifying organisms. organisms.

Understanding Biodiversity….Understanding Biodiversity….

Scientists estimate that there are 5 Scientists estimate that there are 5 million million DIFFERENTDIFFERENT kinds of plants, kinds of plants, animals and microorganisms on animals and microorganisms on earth.earth.

Biodiversity: The variety of Biodiversity: The variety of organisms in a given area.organisms in a given area.

What is taxonomy?What is taxonomy?

GROUPINGGROUPING things according to their things according to their CHARACTERISTICS.CHARACTERISTICS.

GroupsGroups

Kingdom (largest)Kingdom (largest)PhylumPhylumClassClass

OrderOrder FamilyFamily GenusGenus Species (smallest)Species (smallest)

Great way to remember: Kids Play Chase On Freeway Get Squished

KingdomKingdom

Encompasses large groups; such as Encompasses large groups; such as plants, animals or fungi. plants, animals or fungi.

PhylumPhylum

Subgroup within a kingdom. Animals Subgroup within a kingdom. Animals belong to the phylum Chordata. belong to the phylum Chordata. (meaning they have a spinal “chord”) (meaning they have a spinal “chord”)

ClassClass

A sub group within a phylum A sub group within a phylum containing common characteristics.containing common characteristics.

OrderOrder

A sub group within a class.A sub group within a class.

FamilyFamily

A sub group with an order.A sub group with an order.

GenusGenus A sub group within a familyA sub group within a family Species with uniquely shared traitsSpecies with uniquely shared traits Species are thought to be closely Species are thought to be closely

related.related.

SpeciesSpecies

Unique group of organisms united by Unique group of organisms united by heredity or interbreedingheredity or interbreeding

Defined based on unique featuresDefined based on unique features

Changes over time…. Changes over time….

The classification system has The classification system has changed over timechanged over time

Traditionally used appearance and Traditionally used appearance and structure to group organismsstructure to group organisms

Can cause problems – some groups Can cause problems – some groups look similar but turn out to be look similar but turn out to be distantly related others that look distantly related others that look different are closely relateddifferent are closely related

FYI: ExampleFYI: ExampleIn a sense, birds are dinosaurs!

Scientists think that modern birds are descended from a subgroup of dinosaurs – theropods.

They base this information on comparisons of modern birds and fossilized theropods.

What’s in a name?What’s in a name?

Creating Scientific NamesCreating Scientific Names

Carl Linnaeus – 1750’s Carl Linnaeus – 1750’s Catalog all known speciesCatalog all known species Created two-worded Latin names for Created two-worded Latin names for

each species (Binomial Nomenclature) each species (Binomial Nomenclature)

Binomial Nomenclature Binomial Nomenclature (bie NOH mee uhl Noh muhn KLAY chuhr)(bie NOH mee uhl Noh muhn KLAY chuhr)

Scientific Name = Binomial Nomenclature Scientific Name = Binomial Nomenclature

Genus + Species = Scientific NameGenus + Species = Scientific Name

Example = HumansExample = Humans

Homo + Sapien = Homo sapienHomo + Sapien = Homo sapien

Objective BObjective BStudents will be able to Students will be able to

utilize a dichotomous key utilize a dichotomous key to classify organisms.to classify organisms.

We know that this cow is We know that this cow is “Bos Taurus” but…..“Bos Taurus” but…..

““How did How did we get we get there?”there?”

The road to classificationThe road to classification

Requires – keysRequires – keys

Dichotomous KeysDichotomous Keys

Dichotomous KeyDichotomous Key

Assists in Identification Assists in Identification Contains pairs of contrasting Contains pairs of contrasting

descriptionsdescriptions The key directs the user to another The key directs the user to another

pair of descriptors orpair of descriptors or Identifies an objectIdentifies an object

Modern Linnaean System Modern Linnaean System

Changes over time…Changes over time… Category Domain – has been added Category Domain – has been added

(based on rRNA analysis)(based on rRNA analysis)

3 Broad Groups3 Broad Groups EukaryoteEukaryote

– Multiple chromosomes and a mitotic Multiple chromosomes and a mitotic cycle i.e. animalscycle i.e. animals

ProkaryoteProkaryote– Single-Celled does not have nucleus or Single-Celled does not have nucleus or

membrane-bound structures i.e. membrane-bound structures i.e. bacteriabacteria

ArchaeaArchaea– Prokaryotes in extreme environments Prokaryotes in extreme environments

difference in genetic make up of their difference in genetic make up of their cell call. i.e. bacteria in hot potscell call. i.e. bacteria in hot pots