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Introduction

Exercise 1: Graph That Diversity

Exercise 2: Find that Animal

Exercise 3: Phylogenetic RelationshipsExercise 3a.Exercise 3b.

Suggested Reading & Links

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Introduction

There are so many different organisms on Earth To help deal with the great diversity of organisms, scientists

have assigned them into general groups called Kingdoms.

The members of each Kingdom share physical characteristics and similar feeding patterns.

There are five Kingdoms in all. The Kingdom Monera

– Microscopic organisms (bacteria and blue-green algae) that have their genetic material (DNA) loose in a single cell.

– The cell thus has no compartments where specific cell functions would be carried out.

The Kingdom Protista – One-celled organisms with compartmentalized cells. The

genetic material that passes on the traits of parents to their offspring is located in a compartment called the nucleus.

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Like the Kingdom Protista, the following three Kingdoms have cells with compartmentalized function. Organisms belonging to these Kingdoms, however, are composed of many cells and are much larger and more complex than the protists.

The Kingdom Fungi – Organisms (e.g., mushrooms and molds) that feed on non-

living organic matter (deceased organisms and fecal material ). into their simpler chemical compounds.

– In the process these organisms decompose or breakdown the organic material into simpler chemicals.

The Kingdom Plantae – Organisms (e.g., trees, ferns and mosses) that make their

own food using the energy from sunlight.

The Kingdom Animalia – All of the multi-celled organisms (like insects, fish and

mammals) that depend on other living organisms for food

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Unit 6 Materials List

Spinner Magnifying glass Game poster for phylogenetic

tree Mystery Animal Phylum RepresentativesAmphioxus 9ABristle worm 6AClam 5ACoral 2CCrustacean 7AFish 9BFluke 3BHydra 2B

Insect 7B

Jellyfish 2A

Leech 6BOctopus 5B

Planaria3C

Roundworm 4Sand dollar/starfish 8Snail 5C

Sponge 1

Spider 7C

Tapeworm 3AUrchin 8B

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The student will:

Understand the level of diversity (richness of species) that exists in the different kingdoms

Learn how scientists group organisms in the animal kingdom by common characteristics

Learn that scientists have different views on how organisms should be grouped.

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Exercise1. Graph that Diversity

The Kingdom Animalia has by far, the greatest diversity of named organisms (approximately 1,000,000 kinds or species)

Compared to…– The Plantae (300,000 species), – The Fungi (70,000 species)– The Protista (31,000 species)– The Monera (10,000 species).

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Objective

Exercise 1 You have already been provided the numbers of described species for each Kingdom. However it is often easier to compare numbers by looking at them visually (in a picture called a graph).

In this exercise students will compare the diversity among the kingdoms graphically.

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Level Science Standard Math Standard

3 3.5.1 3.1.1, 3.5.1

4 4.5.1 4.1.1, 4.5.1

5 5.5.1 5.1.1, 5.5.1, 5.5.3

6   6.1.1, 6.5.1, 6.5.2, 6.5.3

7   7.1.1, 7.5.1, 7.5.2, 7.5.3

8 8.5.2 8.1.1, 8.5.1, 8.5.2, 8.5.3

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Directions

Divide the class into groups of three or four students

Each group will use graph paper (template provided for zeroxing on next page) to visually compare the diversity of organisms among the different Kingdoms using the three forms of graph listed below:– Bar graph (vertical and horizontal)– Pie Chart – Line Graph

Examine the examples of graphs to help guide you in making your graphs.

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Each group should make a bar graph, line graph, and pie chart using the numbers of species described (named) for each Kingdom listed again below:

Animalia: 1,000,000 speciesPlantae: 300,000 speciesFungi: 70,000 speciesProtista: 31,000 speciesMonera: 10,000 species

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Graph paper template

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Example of a bar graph that compares the number of students in different grades at a

school. Vertical or Y-axis

Horizontal or X-axis

0

200

400

600

800

1st 2nd 3rd 4th 5thGrade

Nu

mb

er o

f st

ud

ents

Class Size

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When you are done checking your bar graph, look at the other graph types shown below.

Then construct your own pie and line graphs after those shown.

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Time to check your answers

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Graphs

Diversity of Living Organisms

0

200000

400000

600000

800000

1000000

1200000

Moner

a

Protis

ta

Fungi

Planta

e

Anim

alia

Kingdoms

Nu

mb

er

of

Sp

ec

ies

Diversity of Living Organisms

0 5E+05

1E+06

2E+06

Moner

aProtis

taFungiPlanta

eAnimal

ia

Kin

gd

om

sNumber of Species

B. Horizontal Bar Graph

A. Vertical Bar Graphor

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Diversity of Living Organisms

0

500000

1000000

1500000

Kingdoms

Num

ber

of S

peci

es

Series1

D. Line Graph

Number of species

Monera

Protista

Fungi

Plantae

Animalia

C. Pie Graph/Chart

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Exercise 2. Find That Animal

This box contains a sample of the huge diversity of creatures that can be found throughout the animal kingdom. Some of these sure do not look much like animals but they are.

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Objective

Exercise 2 familiarizes students with the characteristics/traits that are used by scientists to pigeon-hole animals (place them into groups based on traits they share in common).

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Level Science Standard

1 1.5.1

2 2.5.1

3 3.5.1

4 4.5.1

5 5.5.1

8 8.5.2

Gateway 5.1, 5.2, 5.3

Life Science 5.1, 5.2, 5.3

Biology II 1.1, 1.2, 1.3

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Directions

Divide the class into groups of three or four students

The specimens should be placed at stations around the room by number along with the picture and fact sheet for each animal

Each group should visit each station and:

1) Read the fact sheet that explains the body plan and other characteristics of this particular animal group

2) Examine the specimen noting the characteristics you have read about and any clues that will help you in recognizing this animal type should you see it again

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Directions cont…..

After you are finished looking at the animals and their descriptions:

Your teacher will spin the pointer on the game board and read out the number that it lands on.

Each group should write this clue number down on a sheet of paper.

The teacher will look up the number on the clue sheet and read the characteristics of this mystery animal to the class.

Each group needs to attempt to match the description with the appropriate animal from their notes and and commit this name to writing under the clue sheet number.

Clue Sheet on next page End exercise

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CLUESHEET

0A Hinged shell in fan shape

0B Tentacles line with suction cups

1A Tube-like with tentacles: tiny

1B Distinct jointed legs & wings

2A Coiled shell with small opening

2B Radial (circular) disk with arms

3A Scales, side, top and tail fins

3B Segments, suction cup tapered tail

4A Asymmetrical, plant-like, pores

4B Tiny, brown flat worm

5A Thin white ribbon, segments

5B Branch-like stone with many pores

6A Plate-shaped transparent, tentacles

6B Circular pimpled shell with top hole

7A Segments with legs,cylindrical body

7B Jointed legs,pinchers,tail,antennae

8A Eel-like, thin sliver, no lateral fins

8B 8 eyes, 2 part body, 8 jointed legs

9A Long round worm, tapered ends

9B Very flat worm, sucker mouth

Spin # Clue: Characteristics

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Repeat these steps as many times as desired.

In the end, the group with the most correct answers WINS!!!!

Pictures and Fact Sheets followThe answer sheet

Once all groups have made their decision and recorded it, the teacher will record on the board all of the choices made and how many groups made each one.

Now you can check the answer on the next page and you can discuss the characteristics of the animal that make it unique versus similar to other specimens

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0A Hinged shell in fan shape 5A clam: Mollusca

0B Tentacles line with suction cups 5B octopus: Mollusca

1A Tube-like with tentacles: tiny 2B hydra: Cnidaria

1B Distinct jointed legs & wings 7B insect: Arthropoda

2A Coiled shell with small opening 5C snail: Mollusca

2B Radial (circular) disk with arms 8A starfish: Echinodermata

3A Scales, side, top and tail fins 9B fish: Chordata

3B Segments, suction cup tapered tail 6B leech: Annelida

4A Asymmetrical, plant-like, pores 1 sponge: Porifera

4B Tiny, brown flat worm 3C planaria: Platyhelminthes

5A Thin white ribbon, segments 3B tapeworm: Platyhelminthes

5B Branch-like stone with many pores 2C coral: Cnidaria

6A Plate-shaped transparent, tentacles 2A jelly fish: Cnidaria

6B Circular pimpled shell with top hole 8B sea urchin: Echinodermata

Spin# Clue Characteristic Answer ID#, type, Phylum

ANSWER SHEET

Continued

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7A Segments with legs,cylindrical body 6A bristle worm: Annelida

7B Jointed legs,pinchers,tail,antennae 7A crustacean: Arthropoda

8A Eel-like, thin sliver, no lateral fins 9A amphioxus: Chordata

8B 8 eyes, 2 part body, 8 jointed legs 7C spider: Arthropoda

9A Long round worm, tapered ends 4 roundworm: Nematoda

9B Very flat worm, sucker mouth 3A fluke: Platyhelminthes

Spin# Clue Characteristic Answer ID#, type, Phylum

Answer Sheet continued

Picture key and Fact Sheets follow

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1. Porifera -Sponges Filter feeders on dead organic matter

that rains down on them.

1st animals to consist of many cells.

Their cells, however, are not specialized into tissues but are of four types: Boundary- provide structure and

protection from the external environment.

Pore- border canals that water flows through

Collar- line the walls of the central chamber. Circulate water through sponge & trap food particles

Amoeboid- slithers around, collecting food from the collars, digesting it and distributing the nutrients throughout the sponge

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May have silica (glass), calcium carbonate (limestone) or a protein that makes them inedible.

Defenses are necessary because the sponge is a sessile organism that is permanently anchored onto some substrate.

Sponges can’t run away from predators, so they do not have a nervous system.

The sponge is covered with canals that permit water to enter into a central circulating chamber.

Central chamber collar cells each has a long hair called a flagellum that forces water through the sponge so that food particles will be left behind trapped in the picket fence-like collar.

Sponges vary in size from just a few millimeters to over a meter in diameter.

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2. Cnidaria- Jellyfishes, hydra, corals etc The Cnidaria or Coelenterata are

the first organisms to have tissues.

From outside to inside, these tissues are ectoderm (outer), mesoderm (middle) and endoderm (inner).

Phylum can be recognized by its stinging cells called

nematocysts. These cells are ectodermal

and are continuously produced as they are used.

They kill prey and defend the animal.

2-basic forms

Floating medusa

Anchored hydra

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Endoderm lines the digestive cavity.

Mesoderm is only present as buds or globs (mesoglea) between the other two layers. Mesoglea gives the Cnidaria their body shape and also

gives the jellyfishes buoyancy, allowing them to float in the ocean currents.

The Cnidaria have many characteristics that reflect an inactive or sessile life style.

– Radially symmetrical or circular (shaped much like a pie). This allows the sessile animal to interact with its environment from all directions.

– Cannot move away from predators and thus have stinging cells for defense.

– Nervous system is undeveloped and present only as a nerve net that permits pulsing contractions but no directed movement.

– Reproduction is asexual or vegetative through budding.– Use their tentacles to set up water currents, which carry

potential food items to these stationary organisms.

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2A Jellyfish The jellyfish takes on the medusa

body shape as an adult animal.

It uses buds of mesoderm to float in the seas.

The largest jellyfish has a body that is 3 meters in diameter with tentacles extending 80 meters below the rest of the body.

Generally, jellyfish are marine/ live in salt water where there is greater support offered to this floating organism.

The largest species are located in cold waters.

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2B Hydra Hydras are found in both marine

and fresh water systems.

They are an example of the sessile or anchored form of the phylum Cnidaria.

They wave their tentacles to bring food to their mouths and may contract and shrink in size in response to encounter with an adverse stimulus.

The hydra gets its name from the Greek Goddess Hydra who wore snakes in her hair. The waving tentacles around the mouth give the hydra this same appearance.

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2C Coral Corals are hydra, which live in

colonies.

The specimen in this box is the calcium carbonate skeleton the coral hydra secrete around themselves.

Each hole in the stone-like cylinder would contain a living individual hydra.

Thus hydra with the aid of algae (plant-like seaweeds) build their own houses.

Each species of coral builds a unique skeletal shape. Hence the names, star coral, fire coral, staghorn coral and finger coral.

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Flatworms: Platyhelminthes

Flatworms, with their three clearly defined cell layers (ectoderm, endoderm, mesoderm) and bilateral symmetry, represent an important advance in early animal evolution.

Flatworms lack a body cavity and are flat so that materials can be transported to all parts of the body through simple diffusion.

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The flatworms are the first organisms to possess some form of organ. These organs are simple kidneys called nephridia and are mesodermal in tissue origin as all organs are.

The flatworms are capable of directed movement and thus have nerves and the concentration of nervous tissue in the head region, which is called cephalization. They also exhibit bilateral body symmetry with distinct right and left sides. Cephalization and bilateral symmetry facilitate movement towards and away from stimuli.

The size of an individual flatworm is limited by the fact that it has no respiratory or circulatory system and all exchange of gases occurs through the skin through the process of diffusion.

The body is paper thin to bathe all of the cells in oxygen.

Because of these limitations most flatworms have taken on a parasitic existence where they exist off the nutrients produced by other organisms.

Two examples are provided here of parasitic forms along with one free-living form.

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3A Liver Fluke

The flukes live as parasites on or in animals.

Most flukes have large sucker-like mouthparts and many attack fish.

The animal pictured here is a swordfish fluke.

On your specimen, the white central area is full of reproductive organs as that is what parasites do: reproduce thousands of offspring.

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3B Tapeworm

The tapeworm above is about 90 cm long, much bigger than the dog tapeworm you have embedded in plastic.

All tapeworms spend the adult phase of their lives as parasites in the guts of their primary host animals.

Tapeworms also spend other parts of their life cycle in the tissues of one or more other animals (called intermediate hosts).

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An adult tapeworm consists of a knoblike head, or scolex, equipped with hooks for

attaching to the intestinal wall of the host A neck region A series of flat, rectangular body segments, or proglottids,

generated by the neckThe chain of proglottids may reach a length of 15 or 20 ft

and are the reproductive segments. Each can produce a new worm as its breaks off from the chain and is passed though the gut in feces.

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3C Planaria The planaria are free-living

flatworms. They search for their own food

and are not dependent on a host as parasitic flatworms are.

Planaria, in fact are carnivores

(meat eaters). They creep along the bottom of ponds or under rocks in streams seeking prey.

They are also known for their great power of regeneration in which the two pieces of an individual each replaces its missing parts following the initial split.

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4 Pseudocoelomates

The pseudoceolomate phylaare grouped together becausethey all have what is called afalse body cavity, that is linedon the inside by endoderm andon the outside by mesoderm.

This type of body cavity functions to givethe body shape as it is filled with fluid. It is also important to movement whichoccurs through opposing muscle masses applying pressure on the fluid filled cavity.This deforms the flexible body wall. Needlessto say movement is a non directed flip flopping in the pseudocoelomate worms.

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4 Roundworms/ Phylum Nematoda

The roundworms are the most abundant animals in the World, with as many as 1.5 million individuals in a cubic foot of soil.

Most are parasitic and perhaps the worm that is found encysted in pork is the best known as it causes trichinosis in humans.

Many roundworms are important parasites and consumers of crop plants so they are of considerable economic importance.

Roundworms are tapered at both ends and utilize a hydrostatic skeleton to move (opposing muscles acting on a fluid filled body). They merely flip flop.

Since the roundworm has such an inefficient form of locomotion, parasitism is a good feeding mode for it.

Your specimen is a dog roundworm. That is, it lives in the digestive tracts of dogs, stealing nutrients from their hosts.

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5 Molluscs/ Phylum Mollusca Mollusc (soft shell). All molluscs

have a shell, but in the squids and octopi, it is greatly reduced and internal.

Very successful group that was even more prominent in the seas before the introduction of the fishes.

The archetype is a schematic of what is considered to be the generalized ancestor of modern groups.

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Two features are present, a muscular head foot and a mantle cavity that serves in gas exchange and the ridding of wastes (excretion).

Modern forms have either emphasized the head foot (the snails and chitons) or the mantle cavity (the clams and squids).

There are about 75,000 species in marine, freshwater and even terrestrial systems (the land snails)

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5A Clams

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Clams belong to the mollusc class, Bivalvia because they possess two shells housing greatly expanded gills In addition to providing for gas

exchange, the the gills are used in filter feeding, trapping particles much as occurs in the sponge collar cell.

In other molluscs, the gills are much smaller and are used only for gas exchange.

Your specimen is only one shell of a clam.

The two halves would have been attached at the narrow dorsal end of this shell.

The mouth and gills would have extended ventrally towards the shell edge that opens exposing them when the animal is feeding.

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5B Octopus The octopus is an active predatory

mollusc that is found worldwide in tropical and warm temperate marine waters.

They range in size from less than an inch (2.54 cm) to 15 feet (5 meters) in length.

The octopus uses its mantle cavity as a jet propulsion mechanism for fast locomotion.

Water is sucked into the chamber and forced out through the use of opposing muscle masses that surround the cavity.

The octopus has a well-developed brain and keen eyesight for hunting at night.

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The octopus seizes its prey with its eight long arms. These arms bear two rows of suckers each.

The hundreds of suckers that line their arms help the octopus to hold on to their prey, mainly crustaceans (shrimp, crabs etc.).

If an octopus loses one of its tentacles, it will soon grow another one in the same place.

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5C Snails

Snails (Gastropods) have only one shell naturally.

This shell opens at only one end and is twisted into a spiral coil with a gradually increasing diameter towards the opening. Most coils have a right-handed

spiral. Looking from the opening up to the tip, what is the direction of the spiral on your specimen? Why does the snail have a spiral?

The need to carry the shell to one side and its coiling is related to the fact that snails have a twisted gut that brings the mantle cavity and gills to the front of the body. This modification helped the larval snail to escape predation as it permitted it to pull its head into the shell first as opposed to the tail which is less vital to survival.

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6 Segmented Worms/Phylum Annelida The annelid worms have increased

the efficiency of the hydrostatic skeleton that utilizes opposing muscles a fluid-filled body cavity and a flexible body wall.

The body cavity has been divided into segments with individual muscles, nerves etc. This permits the more controlled movement required of a burrowing animal.

In the ancestral segmented worms, there may have been as many as 200 segments.

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There are three classes of segmented worms Primitive marine worms that swim with

fleshy limbs called parapodia

Terrestial burrowing earthworms

The parasitic leeches which feed on the blood of vertebrates

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6A Bristle Worm

A bristle worm is a member of the marine worm class Polychaeta.

Each segment of the worm has a pair of fleshy limbs called parapodia or ‘almost feet’ that are used in crawling on or burrowing in the seafloor.

Most polychaetes are predators and can also swim in an undulating fashion.

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6B Leech

Most leeches are parasites

They have a sucker at the mouth and sometimes the tail that are used in attaching to the host during feeding.

The leech used as bait by fisherman is a scavenger in streams and ponds, not a parasite.

It has suckers at both ends for attachment to rocks.

Leeches were used in the past to bleed humans when they were sick (ridding them of bad blood).

Few species of leeches are parasitic on humans.

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7 Phylum Arthropoda The Arthropods are specialized,

segmented animals.

Movement has both increased in efficiency over the annelids and diversified through the reduction in the number of segments through fusion and specialization for a variety of functions.

For instance, some of the segments are present as mouthparts and each pair of legs differs in shape and function.

There has also been the development of a hard external skeleton for the legs to push against. This eliminated the functioning of a

hydrostatic skeleton.

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The arthropods use a lever system, hence the name joint-legged.

The hard exoskeleton also does not permit gas exchange through the body surface. Thus respiratory tube systems have been developed, though gas exchange between the tubes and tissue is still passive through diffusion (no lungs).

The arthropods are the most successful of all animals in terms of numbers of species.

Of the three major classes, the crabs, spiders and their relatives, and insects, the insects are the most successful. The development of wings in insects is responsible for this success.

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7A Class Crustacea

Members of the arthropod class Crustacea are primarily aquatic, though the amphipods (pill bugs) are a terrestrial example.

Your specimen is a krill.

The krill are small shrimp-like crustaceans, which are the most important zooplankton species associated with the sea ice and play a key role in the Antarctic food web.

Krill occur in groups or large swarms and feed primarily on phytoplankton or sea ice algae.

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The krill's feeding apparatus is built to filter phytoplankton out of the water column and to scrape algae from the ice.

Krill are the main food source of small fish in the Antarctic seas.

Note the jointed legs and claws and the hard exoskeleton that are characteristic arthropod features.

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7B Class Insecta

Note the wings on the horse fly. These are an example of specialized segments characteristic of the arthropods.

It is the wings that insects possess that have led to their tremendous success in terrestrial habitats. Winged insects can readily disperse from one habitat into another and move between feeding patches.

There are more different insect species in the World than there are of any other organism.

You can use the wing pictures above to help you identify the type of insect you have in your box.

Insect legs and mouthparts are also used in their identification.

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7C Class Arachnida Spiders belong to the arthropod

class Arachnida.

The arachnids have four pairs of walking legs, an accessory pair of pincher-like

appendages in the front that have fangs and are used in subduing prey,

two main body segments.

Spiders are all predators and are best known for their use of silk.

About half of the 30,000 described species of spiders build web traps.

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All spiders, including the ambush and wandering types use silk as a dragline to prevent injury from falls and to encase their eggs in a protective environment.

Spiders have external digestion, taking only liquid meals.

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8 Echinoderms/Phylum Echinodermata

The echinoderms have complex body plans but superficially look more like the sponges than the chordates, their closest relatives.

The larval stage is bilaterally symmetrical like all of the advanced animal groups.

The adults have a radial body symmetry reflecting the sedentary lifestyle they exhibit.

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The primitive group, the crinoids were anchored like sponges, and the star fish, sea cucumbers and sea urchins all are slow moving with movement achieved through a hydrostatic skeleton

Echinoderms are named because of the bony plates they possess in their exoskeletons.

All members of this animal group are marine.

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8A Class Asteroidea: Starfish

True starfish are distinguished from the brittle stars in that they have no sharp demarcation between the arms and central body.

In fact the sand dollars do not have distinct arms but only a central disk.

Starfish move only through tube feet rather than by wiggling their arms.

The starfish are the most speciose of the predatory echinoderm classes.

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They use their tube feet shown above to pry open clams, which are preferred food items.

Some starfish can extrude part of their stomachs out through the mouth, and thus digest food outside of the body.

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8B Class Echinoidea: Sea Urchins

Urchins are browsers: The sea urchin uses a conveyor belt-like apparatus called a radula to scrape algae off rocks in shallow marine waters or on coral reefs.

The specimen you have lacks the protective spines shown in this picture. This is because all that remains is the calcareous skeleton called a teste.

The teste clearly shows the radial body symmetry of the echinoderm and in the living specimen, a spine would extend out of each pimple on the teste.

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9 Chordata

The chordates all have a dorsal hollow nerve chord, a flexible skeletal rod called a notochord and gill slits at some stage in the life cycle.

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9A Cephalochordata

While members of the subphylum Cephalochordata look like fish, they are advanced burrowing animals that have the notochord in the adult stage.

The lancelet, Amphioxus is a filter-feeder that buries itself in the sea floor in shallow marine waters.

It uses its notochord to aid in burrowing. The gills, which are used in breathing also collect small food particles floating by.

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9B Subphylum Vertebrata/ Bony Fish Class

Fish are representative vertebrates, chordates that have the dorsal hollow nerve chord protected by ectodermal material.

These bones take on the form of a segmented skeleton.

In more advanced vertebrates a pelvic girdle is hung from the vertebral column to support the limbs

In most vertebrates, the notochord is only present during embryonic development.

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It is the protection of the nervous system and its greater development that has led to the tremendous success of this subphylum of chordates.

Fish have two characteristics that have led to their great success. – First, they have lateral (side) fins that allow for increased

speed and turning compared to the early verterbrates and swimming, non-vertebrate chordates.

– Second, fish can breathe while stationary by muscular operation of a protective flap (operculum) over their gills. The moving operculum draws water through the mouth, over the gills and expells the oxygen depleted water back out.

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Exercise 3. Relatives of Relatives

Figure 1a resembles a tree.

It represents the phylogenetic tree for the major types of organisms in the Kingdom Animalia.

A phylogenetic tree is used to show the historic relationships among a group of organisms.

At the base of the trunk are organisms that appeared first in history

They are the ancestors of other groups of organisms that branch off of the trunk as each gains new characteristics.

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Fig. 1a. Phylogenetic Tree for Major Phyla of Animal Kingdom

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Thus, this tree demonstrates the idea that new kinds of animals come into existence as modifications appearin existing animals. As a result, the Animal Kingdom today has 30 phyla, each with a distinctive body plan

The major changes in body plan that have occurred over time have been added to the tree in Fig. 1b

Examine Fig 1b, noting the different changes in bodyplan that have occurred with the appearance of new branches.

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Fig.1b. Changes in body plan added (-------)

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For example, the sponges are the first branch of multicellular animals. Organisms below the sponges were single celled and not included in the Animal Kingdom. One-celled organisms are the acestors of animals that are all multicellular.

And the jellyfish and corals branched off even higher than the sponges as the multiple cells they possess are specialized into tissues that perform different functions in the body Ectoderm, endoderm & mesoderm.

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Ectodermal tissue… Forms the boundary layer between the contents of an

animal’s body and the external environment. It also provides structural support in many animals

Skin, hair, feathers, fur and bones are examples of ectodermal tissue.

The stinging cells of jellyfish & corals are also ectodermal.

Endodermal tissue… Is associated with the digestion of food The guts of all animals above the sponges on the tree are

lined with endodermal tissue.

Mesodermal tissue Muscles Organs such as the heart, lungs and kidneys

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Once a new characteristic develops along the main trunk of the tree, all new branches that come off of the trunk have the new characteristic.

Example: Organs first appeared in the flatworms in the form of primitive kidneys that removed waste. The animal groups on all of the branches above the flatworms have some form of kidney.

Other organs such as the heart, lungs and liver first appear in animal groups that are further up on the phylogenetic tree. These organs are developed into increasingly more complex structures in the higher branches.

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Notice that the trunk of the tree splits into two smaller (secondary) trunks after the appearance of the clams and their relatives representing the molluscs.

The animal groups formed after the split are related to members of the opposite branch only to the extent that their ancestors were organisms on the main trunk before the split occurred.

Thus, the annelid worm group to which the earthworms belong is according to this historical tree the ancestor of the arthropods (insects, spiders, and crabs) but is not the ancestor of the vertebrates (fish, amphibia, reptiles, birds and mammals).

Rather, the vertebrates are more closely related to the echinoderms (starfish, sea urchins and sea cucumbers).

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Objective

Exercise 3 permits students to use their new knowledge about the organism’s characteristics by asking them to construct a phylogenetic tree

Level Science Standard

8 8.5.2

Gateway 5.1, 5.2, 5.3

Life Science 5.1, 5.2, 5.3

Biology II 1.1, 1.2, 1.3

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Exercise 3a. Understanding Historical

Relationships Now that you know how the phylogenetic tree works, see if you can

determine where all of the animals in the trunk go on the tree.

Study Fig. 1b noting the changes in body plan that are associated with each branch and the animal group that is associated with the new feature.

Now find the poster with a similar tree to that shown in Fig. 1 in the box. This tree has branches without the animal groups shown on it.

It is also displayed on the next slide Lay out the poster on a flat surface at the front desk As a class decide and place each specimen on the tree branch you

think it belongs on without referring to Fig. 1. Note: A key to the colors on the tree is available (Hand Out). Each

color represents a few characteristics that the animal must possess in order to fit on that branch.

Use this key to help you place the animals in the appropriate position on the tree poster.

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KEY (handout)

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Time to check your answers

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Exercise 3b. Comparing TreesFigure 2 demonstrates an important aspect of biology and science in

general. There may well be different hypotheses as to how systems function and, in this case, how organisms are related to one another.

Fig. 2. Comparison of two different proposed branching patterns for higher invertebrates

True Coelom

FalseCoelom

CuticleSheds Skin

Lack CuticleNo Shedding

Flatworm Flatworm

RotiferNematode Rotifer

Nematode

Arthropod ArthropodAnnelid

AnnelidMollusc

Mollusc

organ level

coelom level

Based on one gene &presence/absence of cuticle skin covering

Based on pattern of development

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Directions

Find examples of the animals that are represented in Fig. 2.

Now compare the lineages shown in Fig. 2 to that you have been working with in Fig. 1.

Note: The lineage on the right side of the chart is the most widely accepted hypothesized tree.

The tree on the left has been recently hypothesized to explain the molecular results of the analysis of one gene system.

The animals possessing a skin covering called a cuticle that must be periodically shed during growth are more similar in their genetic make-up than the animals lacking this cuticle.

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Question 1: Which animal groups are displaced in the tree depicted in Figure 2 from where they are located in the tree based on development?

Stop!!! The answer is next!!

The Arthropods including spiders, crabs and insects which have a true coelom or body cavity developed to house complex organ systems are taken out of the lineage containing other groups that have a true coelom (molluscks and segmented) worms) and moved into a lineage that includes organisms that have a false coelom or a body cavity designed mainly to provide shape in the absence of a skeleton.

Question 2: How might the validity of the two alternative trees be tested?

Stop!!! The answer is next!!

One thing that can be done is to examine more genes to determine whether the relationships suggested with the sequencing of one gene are supported by other gene sequences.

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Suggested Reading1. The Beauty of the Beast: Poems from the Animal Kingdom

Jack Prelutsky, Meilo So (Illustrator), Meilo So (Illustrator)

2. Sponges, Jellyfish and Other Simple Animals by Steve Parker, Daniel Gilpin, Steve Parker (Illustrator)

3. Variation and Classificationby Ann Fullick

4. Sponges, Jellyfish, and Other Simple Animals (Animal Kingdom Classification). Steve Parker.

5. What’s That Bug? Nan Froman. Illustrated by Julian Mulock.

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Links

Exercise 1

http://waynesword.palomar.edu/trfeb98.htmKingdoms

http://www.worldagroforestrycentre.org/sites/RSU/resources/biodiversity/analysistypes/richness.aspSpecies Richness

http://nces.ed.gov/nceskids/graphing/creating graphs

Exercise 2

http://waynesword.palomar.edu/trnov01.htm

http://cas.bellarmine.edu/tietjen/images/general_overview_of_animal_phyla.htm

http://ebiomedia.com/gall/awob/index.html\

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Exercise 3

http://aleph0.clarku.edu/~djoyce/java/Phyltree/cover.htmlconstructing phylogenetic trees

http://www.tolweb.org/tree/Tree of Life Project