Lecture 3Classification

The problem with common names

Hirola Island grey fox Green eyed frogNational geographicNational geographicNational geographic

EKECa

Hermit crab King crab : Genus Pagurus

Aristotle 384BC

• He classifies either plant or animal– Plants subdivided into three groups– shrubs, herbs, and trees– Animals were subdivided by where they lived on land, water or in the air

• This does not solve the problem– Example: birds, bees and bats !!!– Not the same

ClipArt ETC

Along comes Taxonomy by Linnaeus

Carols Linnaeus 1750

• System still used today– classifying organisms properly– physical and structural similarities

• Two-word naming system = Binomial Nomenclature• Binomial nomenclature is a scientific naming

system that gives each species a two-part scientific name– uses Latin words – scientific names always written in italics – two parts are the genus name and species descriptor

• A genus includes one or more physically similar species– Species in the same genus are thought to be closely

related– Genus name is always capitalized

• A species descriptor is the second part of a scientific name– can be in italics or underlined, but always lowercase– always follows genus name; never

written alone (same word can be used in other genera: alba means white and is used in naming the white oak tree)

– It can refer to a trait of the species (white)

Tyto alba

• BINOMIAL NOMENCLATURE 1. Linnaeus's classification hierarchy included five levels

(KINGDOM, CLASS, ORDER, GENUS, AND SPECIES) Modern scientist have added TWO more classifications levels to the original five (PHYLUM AND FAMILY

2. Today we have SEVEN LEVELS OF CLASSIFICATION:      A. KINGDOM

    B. PHYLUM (DIVISION - IN THE PLANT KINGDOM)     C. CLASS     D. ORDER     E. FAMILY     F. GENUS     G. SPECIES

3. KING PHILIP CAME OVER FOR GRANDMA'S SOUP.

Problem solved?

• The tree of life shows our most current understanding.

• New discoveries can lead to changes in classification.– Until 1866: only two kingdoms,

Animalia and Plantae

– 1938: prokaryotes moved to kingdom Monera

– 1866: all single-celled organisms moved to kingdom Protista

– 1959: fungi moved to own kingdom

– 1977: kingdom Monerasplit into kingdoms Bacteria and Archaea

Animalia

Protista

Fungi

Plantae

Archea

Bacteria

This is how things progressed

Consider the following animals in the Deerus genus. They are all related, but each is a

separate species. Use the dichotomous key below to determine the species of each.

1.

Has aqua colored body ......go to 2

Has blue colored body ..... go to 4

2.

Has 4 legs .....go to 3

Has 8 legs .......... Deerus octagis

3.

Has a tail ........ Deerus pestis

Does not have a tail ..... Deerus magnus

4.

Has a pointy hump ...... Deerus humpis

Does not have a pointy hump.....go to 5

5.

Has ears .........Deerus purplinis

  Does not have ears ......Deerus deafus

Macro evolution Plate tectonics

5 Mass extinctions