What are the three domains of life? of the animal … › classes › bio182 › Molly › Andivers1...Page ‹#› Animal diversity 1 - Evolution of the animal body plan Key concepts

Page ‹#›

Animal diversity 1 - Evolutionof the animal body plan

Key concepts for today• Definition of an animal• Major phyla, and their relatedness

(where they are on a tree)• Major stages in evolution of animal

body plan and where they occurred

1

What are the three domains of life?BacteriaArchaeaEukaryaWhat are the kingdoms?BacteriaArachaeaprotistsPlantaeFungiAnimalia 2

Phylogenies of the deep roots of lifeare controversial(not to memorize:) 2005 revision of Eukarya

kingdoms: instead of three, six: four protistkingdoms, “Opisthokonta” (fungi + animals)and “Archaeplastida” (plants)

Among protist systematists, even thisarrangement is controversial. “I’ve seenpeople throw things at each other” one of theauthors says.

Your text book has a different arrangement ofanimal phyla. The one we will focus on todayis used in Lab 4 - learn this one rather than theone in the book.

Why can’t we reconstruct these ancientdivisions with certainty?

2a

What features together define amember of the Kingdom Animalia?

MulticellularityIn what Kingdom do animal-like single

celled creatures belong?Are all protists unicellular?What else is common to all animals?Heterotrophic life styleHeterotrophic? Autotrophic?

3

What features together define amember of the Kingdom Animalia?

MulticellularityHeterotrophic life styleAnd?Extracellular matrix (ECM)- extra (outside) cellular (cells) matrix

(“stuff” or more precisely “substancewithin which something originates,develops, or is contained”)

4

Extracellular matrix (ECM)

Made up of proteins andglycoproteins

Give animal cells and animalsstructure

Hard stuff in bone, cartilage, formssoft barriers and filters aroundcells, e.g. gut linings

Same as a cell wall?

5

Page ‹#›

What other traits do you associatewith animals?

Why do they have them?

Do all animals have them?

6

Animal quiz: Are each of theseanimals? If so, what phylum?

7


8


9


10

Animal quiz: Are these animals? Ifso, what phylum?

11

Page ‹#›

Animal quiz: Are these animals? Ifso, what phylum?

12


13

Today - evolution of the animalbody plan

14

One hypothesis for evolution ofmajor animal phyla

p. 52 of your lab manual15


PROTISTS

PORIFERA

16


PROTISTS

PORIFERA

CNIDARIA

17

Page ‹#›


PROTISTS

PORIFERA

CNIDARIAPLATYHELM

INTHES

18


PROTISTS

PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA

19


PROTISTS

PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA

PROTOSTOMES

DEUTEROSTOMES

20


PROTISTA

PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA

PROTOSTOMES

DEUTEROSTOMES

ARTHROPODA

ANNELIDA

MOLLUSCA

21


PROTISTS

PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA

PROTOSTOMES

DEUTEROSTOMES

ARTHROPODA

ANNELIDA

MOLLUSCA

ECHINODERMATA

CHORDATA

22

What key features differentiate animalsfrom protists?

PROTISTS

PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA

PROTOSTOMES

DEUTEROSTOMES

ARTHROPODA

ANNELIDA

MOLLUSCA

ECHINODERMATA

CHORDATA

23

Page ‹#›

What key features differentiate animalsfrom protists?

PROTISTA

PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA

PROTOSTOMES

DEUTEROSTOMES

ARTHROPODA

ANNELIDA

MOLLUSCA

ECHINODERMATA

CHORDATA

MULTICELLULARITY, ECM 24

Simple animals - the Porifera(Sponges)

25

Where do our sponges get theirname?

26


Tubeorganization

Cells that movewater and absorbfood“Choanocytes”

Several celltypes in ECM -like fruit in jello

Fig. 32.4from text

H2O

H2OPore cells

choanocytes

27


Protist ancestors ofanimals?

Spongechoanocyte

Choanoflagellates colonialprotists with similar celltypes

Since 1880ssimilarity noted

choanoflagellate

Recently (2001):signalling gene incommon 28

Simple animals with cellularorganization - the Porifera (sponges)The choanocytes

Regulate H20 movement withflagellum

Collect food particles at flagellumbase, absorb directly into the cell

29

Page ‹#›

So, sponges have what kind ofdigestion?

Intracellular digestion - digest foodwithin individual cells

What does this mean about the sizeof the food they can eat?

30

Party trickswith sponges…

Cells from a sponge can becompletely disassociated, strainedthrough a filter...

And they will re-form into a spongeagain in a few weeks

What does this mean about the waythey are organized? 31

If a tissue is a group of similarcells organized into a functionalunit, do sponges have tissues?

Sponges have cellularorganization

Simple animals with cellularorganization - the Porifera (sponges)

32

One last thing about sponges…

They’reasymmetrical

-tubes grow intoother tubes - can’tbisect them andmake two equalhalves

33

The Cnidaria

34

The Cnidaria

Cross section of asea anenome

Two cell layersTentacles around

a mouth thatcloses

Is it symmetrical?

35

Page ‹#›

Evolution of symmetry

Bilateralsymmetry

Radialsymmetry

Asymmetrical

36

Radial symmetry

A plane through the center in anydirection will bisect the organism intoequal halves 37

Bilateral symmetry

Only a single plane will bisect theorganism into equal halves 38

Advantages of bilateralsymmetry?

A front and a back aswell as a top and abottom

Allows concentration ofsensory apparatus onone side (front) of oneend (top!)

Why is this a good thingfor mobile animals?

39

The innovations of the Cnidaria Cells work together in

layers: tissueorganization

If we disassociated thecells of a cnidarian andleft them in a tank ?

Cross section of asea anenome 40

The innovations of the Cnidaria

Cnidarian dining

What kind ofdigestion?


Page ‹#›


Extracellulardigestion

What does this meanabout the size offood they canconsume?


The innovations of the Cnidaria Do cnidarians have

a gut?Where do their

waste productsgo?

Mouth but no anusWhat are the

problems withthis?



Review:Radial symmetryExtracellular digestionMouth but no anus - in Nematoda have

both

And…No coelom

44

Evolution of the coelom

What’s a coelom?Is it the same thing as a gut?Where is the coelom on humans?

45

Evolution of the body cavity - thecoelom

In humansdividedinto two -thoracicandabdominalcavities

Inearth-worms,coelomin eachseg-ment

46

We will distinguish between 3 types ofanimals

Acoelomate (‘a’-without) - e.g.Sponges, Cnidaria, Flatworms(Platyhelminthes)

47

Page ‹#›


Acoelomate (‘a’-without) - e.g.Sponges, Cnidaria, Flatworms(Platyhelminthes)

EctodermMesoderm -solid

Endoderm

Gut cavity 48


Pseudocoelomate - e.g. Nematoda

EctodermMesodermlayerCavity

Endoderm

Gut cavity49

We will distinguish between 3 types ofanimalsCoelomate - e.g. all protostomes and

deuterostomes Mesodermsurrounds cavity (coelom) and gut

EctodermMesodermlayers (two!)

CavityEndoderm

Gut cavity 50

Which is acoelomate? Coelomate?Pseudocoelomate?

51

Why was evolution of a coelomimportant in animal evolution?3 reasons (not all relevant for all groups)1) Coelom can function as a simple

circulatory system2) Fluid in a body cavity can help make

the body rigid - a hydrostatic skeleton3) Organs can function without being

deformed by surrounding musclesAllows the development of a longer gut, can be

coiled, etc.How long is the combined human small and

large intestines? 52

What differentiates these groups?

PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA

PROTOSTOMESDEUTEROSTOMESARTHROPODA

ANNELIDA

MOLLUSCA

ECHINODERMATA

CHORDATA

PROTISTA 53

Page ‹#›

Groups can be distinguished byearly embryonic development

Blastula Gastrula

Blastopore

54

In Protostomes (‘proto’-first, ‘stome’-mouth)- the blastopore gives rise to the mouth

Blastopore

55

In Deuterostomes (‘deutero’- 2nd, ‘stome’-mouth) - the blastopore gives rise to theanus

Blastopore

56

Mapping body plan characters onthe tree

PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA


ANNELIDA

MOLLUSCA

ECHINODERMATA

CHORDATA

PROTISTAMULTICELLULARITY, ECM

EXTRACELLULARDIGESTION?

57

Mapping body plan characters on the treePO

RIFERACNIDARIA

PLATYHELMINTHES

NEMATO

DA


ANNELIDA

MOLLUSCA

ECHINODERMATA

CHORDATA

PROTISTAMULTICELLULARITY

TISSUES?EXTRACELLULAR DIGESTION

58


PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA


ANNELIDA

MOLLUSCA

ECHINODERMATA

CHORDATA

PROTISTAMULTICELLULARITY

RADIALSYMMETRY?BILATERALSYMMETRY?EXTRACELLULAR DIGESTION

TISSUES

59

Page ‹#›


PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA


ANNELIDA

MOLLUSCA

ECHINODERMATA

CHORDATA

PROTISTAMULTICELLULARITYEXTRACELLULAR DIGESTION

TISSUES

RADIAL SYMM

ETRY

BILATERAL SYMMETRY

MOUTH ANDANUS?

60


PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA


ANNELIDA

MOLLUSCA

ECHINODERMATA

CHORDATA


TISSUES

RADIAL SYMM

ETRY

BILATERAL SYMMETRY

TRUECOELOM?MOUTH AND ANUS

MO

UTH AND ANUS

61


PORIFERA

CNIDARIAPLATYHELM

INTHESNEM

ATODA


ANNELIDA

MOLLUSCA

ECHINODERMATA

CHORDATA


TISSUES

RADIAL SYMM

ETRY

BILATERAL SYMMETRY

MOUTH AND ANUS

MO

UTH AND ANUS TRUE COELOM

62

Documents

What are the three domains of life? of the animal … › classes › bio182 › Molly › Andivers1...Page ‹#› Animal diversity 1 - Evolution of the animal body plan Key concepts