• Sea-side Splat!

Key Words:

• Classification

• Taxonomy

• Taxon

• Phylogeny

• Binomial system

• Dichotomous key

• Classification is the grouping of organisms based on similarities of

features.

• Taxonomy is the science of studying classification. It looks at features and tries to arrange them in a logical order.

A ‘TAXON’ is a unit of hierarchical classification:

• ‘hierarchical’ means in ascending sequence.• A ‘species’ is the fundamental taxon • Groups of similar species form the next

largest taxon called a ‘genus’.• Groups of similar genera form the next

largest taxon called a ‘family’• …and so on, up to the largest taxon =

Kingdom.

What do you notice about how the names are written?

• Fucus vesiculosus

• Fucus serratus

• Enteromorpha intestinalis

• Patella vulgata

• Balanus balanoides

• Actinia equina

• Littorina littorea

‘Binomial’ = 2 names

Fucus vesiculosus

Genus – has a capital letter

species – all in lower case

Italics (or underlined)

-to show the words are different to ordinary text.

• Panthera leo

• Panthera tigris

• Panthera pardus

• Canis lupus ( and Canis domestica)

• Pan troglodytes

• Ovis aries

• Rattus norvegicus ; Rattus rattus

• Perca fluviatalis

• Carcharodon carcharias

…and some easier ones!

• Boa constrictor• Gorilla • Giraffus• Hippopotamus amphibius• Bison bison• Equus zebra• Tyrannosaurus rex• Elephas maximus

Classification is hierarchical!Each unit is called a TAXON –

there are 7 of them.

KingdomPhylum

ClassOrder

Family Genus species

Taxon Cat Man

KINGDOM

PHYLUM

CLASS

ORDER

FAMILY

Genus

species

Animalia Animalia

Chordata Chordata

Mammalia Mammalia

Carnivora Primates

Felidae - cats Anthropoids - apes

Felis Homo

cattus sapiens

You need to remember the sequence for the exam… so

here’s how!

‘Kinky Priests Come Over For Great Sex’

Phylogeny

• A phylogenetic tree is a family tree that shows a hypothesis about the evolutionary relationships thought to exist among groups of organisms. It does not show the actual evolutionary history of organisms.

• Why a hypothesis?

Phylogenetic trees are usually based on a combination of these lines of evidence:

    Fossil record

    Morphology

    Embryological patterns of development

    Chromosomes and DNA

Fossils

Similar morphology

http://www.sciencecartoonsplus.com/

Embryology

DNA similarities

A phylogenetic tree

The Dichotomous key

• A key is a device for easily and quickly identifying an unknown organism.

• The dichotomous key is the most widely used type in biological sciences.

• The user is presented with a sequence of choices between TWO statements, couplets, based on characteristics of the organism. By always making the correct choice, the name of the organism will be revealed.

1.  

A. one pair of wings ( goto 2)

B. Two pairs of wings (goto 3)

Make a dichotomous key

Phylogenetic example:

1 a) Endotherm (constant body temperature) Goto 2

b) Ectotherm ( cold-blooded) Goto 5

2 a) Fur Goto 3

b) Feathers Parrot

3 a) Fins Whale

b) At least two legs Goto 4

4 a) wings Bat

b) 4 legs Cat

5 a) fins Fish

b) No fins or limbs Snake