Genetics 1: Classification of

Lifeppt. by Robin D. Seamon

1

HOOK VIDEO: COSMOS-“Some Things Molecules do”

3 Domains:

Prokaryote: no nucleus or organellesEukaryotes: nucleus & membrane-bound organellesVIDEO: How we think complex cells evolved (5:30)

2

NEW There are 3 Domains

K

C

O

F

S

G

P

RANKING SYSTEM

3

4

CC video: comparative anatomy (10 min)

Kingdom Archae-bacteria

H I S T O R Y

Aristotle: (Greek philosopher 384-322 CE) classified animals based on method of reproduction

5

Taxonomy: group or categorize organisms

• Before 1700, there were multiple long names for new species with no rules in naming process

Carl Linnaeus (Swedish) 1735grouped organisms by shared physical characteristics

• wrote Systems Naturae

3 Kingdoms: 1. Mineral

2. Vegetable

3. Animal

6

Today naming is regulated by Nomenclature Codes allowing names to be divided into ranks:

Binomial nomenclature (genus & species) 1740’s

R A N K I N G S Y S T E M

7CC Video: #19 Taxonomy(12 min)

• 1859 Darwin insisted classification should reflect genetic relatedness

• 1900 Emil Willi Henning: grouped organisms by inferred evolutionary relatedness

• Homologous structures; inherited from common ancestors, so were related

Phylogenetic taxonomy

8

• Cladistic system: 1960’s scientists started using DNA sequences to determine common ancestry IGNORING RANKS

• This new field is making changes & revisions in classification everyday.

• International Code of Phylogenetic Nomenclature (PhyloCode) is currently under development

Molecular Phylogenetics

C L A D E S Y S T E M

9

• 1990’s: New Grouping based on new discoveries in bacteria metabolism

1. Archaea

2. Bacteria

3. Eukaryota

D O M A I N S

Separated these 2

Includes Protists

10

CC Video: #35 Archaea, Bacteria, Protists (12 min)

11

Archaea- ancient group of prokaryotic organisms that are still present today --Extremphiles- types of archaea that live in very extreme placesSome examples:

• Halophile: live in extreme salty conditions

• Thermophile: live in extremely hot conditions

• Methanogen: metabolize such that they use acidic conditions (sulfur) and release methane

12

Hiller Lake, Australia

Halophilic archaea & bacteria live in this salty lake

BACK

Under-ocean hot vent

13

Yellowstone hot vent, Wyoming

thermophilic archaea & bacteria live in this hot vent BACK

14

Methanogenic archaea

BACK

15

Bacteria- ancient group of prokaryotic organisms that are still present today

16

Eukaryota- group of organisms whose cells contain a nucleus and membrane-bound organelles

ALL THE REST

Phylogenetic tree

17

H I S T O R Y O F C L A S S I F I C A T I O N

1735Linnaeus

1866Haeckel

1925Chatton

1938Copeland

1969Whittaker

1990Woesse

1998Cavalier-

Smith

2 Kingdoms 3 Kingdoms 2 Empires 4 Kingdoms 5 Kingdoms 3 Domains 6 Kingdoms

Mineral Prokaryote Monera Monera Bacteria Bacteria

Protist Protist Protist Archaea Protist

Eukaryote Eukaryote Chromista

Vegetable Plant Plant Plant Plant

Fungi Fungi

Animal Animal Animal Animal Animal

To apply Darwin to

Microscopic organisms

To show having

nucleus or not

To show evolutionary

history of life

18

1969 Whittaker: 5 Kingdoms

Protists

Monera

PlantsAnimals

Fungi

Prokaryotes: Eubacteria &

Archeobacteria

Eukaryotes

Absorb & photosynthesize

Asexual Reproduction

Absorb & photosynthesize

Asexual & Sexual Reproduction

Photosynthesize

Asexual & Sexual Reproduction

Non-mobile

Ingest

Asexual & Sexual Reproduction

mobile

Absorb

Spores: asexual Reproduction

Non-mobile

19

1990 Woese: 3 Domains

Eukaryotes

PlantsAnimals

Fungi

Protists

Photosynthesize

Asexual & Sexual Reproduction

Non-mobile

Absorb

Spores: Asexual Reproduction

Non-mobile

Archaea CBacteriaMonera Monera

Absorb & photosynethsize

Aerobic respiration

Asexual & Sexual Reproduction

Various metabolism: photosynthesis, fermentation,

Methanogenesis respiration

Asexual Reproduction

Various metabolism: photosynthesis, fermentation,

Anaerobic & aerobic respiration

Asexual Reproduction

Ingest

Asexual & Sexual Reproduction

mobile

NO NUCLEUS

NO NUCLEUS

NUCLEUS

DOMAIN DOMAIN DOMAIN

20

Protist

Fungi

Tree of life Web Project

Tolweb.org

21