Module 17: The Diversity of Animal and Fungus Life

Domains and Kingdoms of Life

• Earth – 4.6 BYA

•  Prokaryotes – 3.8 BYA

•  Eukaryotes – 2.0 BYA

•  First Animals – 635 MYA

What is an Animal?

• Multicellular, heterotrophic, eukaryotes.

•  Lack cell walls 

  • Collagen: connective tissue of most animals.

• Contain muscle and nervous tissue.

  •  Allow for movement and nerve impulses.

•  Most reproduce sexually.

 Asymmetrical:

•  no symmetry.

•  Radial symmetry: 

• body parts distributed evenly around a central point

•  Bilateral symmetry: 

• opposite sides of sagittal plane are mirror images of one another

Digestive System

• Animals have diverse nutritional requirements and feeding strategies.

Intercellular digestion: 

• digestion inside cells

Gastrovascular cavity:

central cavity with a single opening that functions in both digestion and distribution of nutrients.

Alimentary canal: 

• digestive tract with two openings (mouth and anus). 

Hydrostatic skeleton: 

• Water held under pressure within a closed body compartment.

  • Cnidarians, Flatworms, Annelids, Roundworms.

Exoskeleton:

•  hard covering deposited on the animal's surface that provides protection and points for muscle attachment.

  •  Arthropods, Molluscs.

Endoskeleton:

•  hard ossified skeleton buried within soft tissue.

  •  Sponges, Echinodermata, Chordata

Segmentation

•  Series of repeating parts or body segments.

  • Efficient movement .

  •  Movement of parts

• Evolved independently in three phyla:

•  Annelida

• Arthropoda

•  Chordata

Protostome

• mouth developes from blastopore

  • mouth develops first

Deuterostome

• anus developes from blastopore

  • anus develops first

Invertebrates

• Animals without a backbone 

Sponges

• No tissues or organs 

• Intercellular digestion

• Protostome development 

• Filter-feeders

• Free-swimming larvae 

• Sessile as adults

Choanocyte: 

• Specialized cells with flagella that create water current up through osculum 

Osculum

• opening at the top of the sponge.

( The small purple cells within the gel layer are called amoebocytes) 

They engulf food within the gel layer

Cnidarians

• Sea jellies,

• Corals

• Sea anemones

CHARACTERISTICS:Cnidarians

•  Protostome development.

•  Radial symmetry.

•  Gastrovascular cavity.

•  Cnidocytes: stinging cells.

•  Two life stages:

  •  Medusa

  • Polyp

Flatworms

• Tape worms

• flukes 

CHARACTERISTICS: Flatworms

•  Protostome development.

•  Bilateral symmetry.

•  Lack of gas exchange structures.

  • Rely on diffusion.

•  Hydrostatic skeleton.

•  Well-defined head and tail regions.

•  Hermaphroditic.

  •  Can engage in both sexual and asexual reproduction

Annelida

• Earth Worms

• leaches,

• polychaete worms 

• Proper cardiovascular system with heart & vessels

CHARACTERISTICS: Annelida

• Protostome development.

• Hydrostatic skeleton.

•  Bilateral symmetry.

•  Segmented bodies.

•  Complete digestive tract

Molluscs 

• clams

• snails,

• octopus 

CHARACTERISTICS: Mollusces

• Protostome development.

•  Bilateral symmetry.

•  Exoskeleton (shell), Hydrostatic in some.

•  Alimentary canal.

•  Radula: scraping mouth part.

•  Muscular foot.

•  Mantle.

  • Forms shell

Round Worms 

Nematodes 

CHARACTERISTICS 

•  Protostome development.

•  Exoskeleton.

  • Molt exoskeleton to grow.

• Bilateral symmetry.

•  Alimentary canal.

•  Many are parasitic.

Arthropods 

Includes barnacles, spiders, insects, millipedes and crustaceans 

CHARACTERISTICS 

•  Protostome development

•  Bilateral symmetry

•  Alimentary canal

•  Ecdysis 

  • Molt exoskeleton to grow

•   Jointed appendages

•  Segmented bodies

  •  Head, thorax, abdomen

General Anatomy of Arthropods

• Open circulatory system

  •  Hemolymph: circulatory fluid.

•  Highly developed sense organs:

  •  Compound eye.

  •  Antennae.

    •  Touch and smell.

  • Olfactory receptors.

•  Specialized mouthparts for various feeding behaviors

Echinoderms

• Sea stars

• sea urchins,

• sand dollars,

• sea cucumbers

CHARACTERISTICS:Echinoderms

•  Deuterostome development.

  •  Shares a common ancestor with chordates.

•  Radial symmetry evolved from bilateral symmetry.

•  Alimentary canal.

•  Endoskeleton.

•  Tube feet:

  •  Locomotion and sensory system.

Chordates

Includes fish, reptile, birds, and mammals

CHARACTERISTICS:

•  Deuterostome development.

•  Bilateral symmetry.

•  Alimentary canal.

• Endoskeleton.

•  Dorsal hollow nerve cord.

•  Notochord.

•  Pharyngeal gill slits.

•  Post anal ta

Includes fish, amphibians, reptiles, birds, and mammals

• Notochord

•  Dorsal nerve cord:

•  Pharyngeal slits:

• Post-anal tail:

Notochord

develops into vertebrate column in vertebrate.

 Dorsal nerve cord:

develops into brain and spinal cord in vertebrates.

 Pharyngeal slits:

• gills in fish, present in embryos of terrestrial vertebrates but disappears during development.

 Post-anal tail:

present in embryo of humans, becomes tail bone

Fishes

•  More fish species than all other vertebrate groups combined.

•  Jawless fish

  •  Hagfish

•  Cartilaginous fish

  • Sharks, skates and rays

•  Bony fishes

  •  Ray finned fish

•  Teleosts

  •  Lobe finned fish

•  Lungfis

Adaptations to Terrestrial Environments

• Jaws

• Lungs

• Limbs

•  Amniotic egg:

Jaws

• Allowed organisms to grasp food.

  •  Diversification of feeding methods.

Lungs

• Allowed organisms to breathe air outside of water.

Limbs

• Allowed organisms to move around and search for food on land.

 Amniotic egg:

• Allowed for organisms to reproduce away from water.

Vertebrates Move onto Land

Early Tetrapods→Amphibians —> Reptiles —> mammals & dinosaurs (birds) 

Tiktaalik (~ 375 mya)/ Traits of fish & amphibian:

• Gills,

• scales,

• lungs,

• flexible neck,

• four legs

Amphibians

Frogs and Salamanders

•  Approximately 6,150 species.

•  Most go through metamorphosis (“two lives”).

  •  Aquatic, gill breathing larvae.

  • Terrestrial, lung breathing adults.

• Thin, highly vascularized skin.

•  Three-chambered heart.

•  Ectothermic.

 Gymnophiona (caecilians) 

•  The unknown amphibian.

  • 200 species of slender, limbless, snake-like amphibians.

  • Predators that burrow in wet, tropical regions

Amniotic Egg

• Egg with hard outer casing (shell) and inner supportive membranes that provide padding to the developing embryo.

  • Reptiles and a couple mammals have leathery eggs.

  •  Birds have hard shells.

  •  “Egg” evolved to for placenta in mammals.

“Reptiles”

Snakes, lizards, tortoises, crocodiles and birds

• Ectothermic.

  •  Except birds

•  Three-chambered hearts.

  •  Except crocodiles and birds (4 chambers)

•  Scales and scutes.

•  Lungs.

  •  No embryonic stage with gills.

Extant Dinosaurs - Birds

Ostrich, penguins, kiwi, sparrows, eagles, and albatross

•  Endothermic dinosaurs.

•  Four-chambered heart.

•  Feathers.

•  Wings.

•  Bill with no teeth.

•  Strong, lightweight skeleton.

Mammals

Monkeys, giraffes, rats, tigers, whales, elk, and humans

•  Endothermic.

•  Four-chambered heart.

•  Hair at some point of their development.

•  Mammary glands produce milk.

•  Three inner ear bones.

•  Differentiated teeth.

Monotremes

• egg laying mammals

  •  Echidna and platypus

Marsupials

• most of their young's development occurs within a pouch.

  •  Kangaroo and opossum

Placentals

young develop within a placenta inside of mother

Primates: Lemurs, lorises, monkeys, apes, humans

• Nails instead of claws.

•  Clavicle.

•  Two lower limb bones.

•  Opposable thumb.

•  Reduced snout.

•  Reduced olfactory region of brain and increased cerebrum .

•  Binocular vision.

  •  Depth perception

Humans and Apes: Homo sapiens characteristics

•  Bipedalism

  •  Evolved early on.

• A big, fat brain (literally).

  • Language

  • Symbolic thought

  • Artistic expression

  •  Use complex tools

•  Reduced jaw bones and jaw muscles.

• Differ from chimpanzees in 19 regulatory genes

Fungi: What are they?

•  Single-celled or multicellular eukaryotes:

  •  Many are mutualistic with plants.

  • About 110,000 described species.

•  Total number estimated at 6 million species

Many cause problems…but not all!

Many cause problems…but not all! (fungi)

• Many are pathogenic:

  • About 300 cause human illness.

  •  Many more infect plants.

•  Important decomposers in many ecosystems.

•  Human benefits:

  •  Food: mushrooms & yeast.

  •  Antibiotics.

I, Fungi

•  Single-celled forms: yeasts.

•  Multicellular, filamentous forms – mycelia.– Some species exhibit both forms

fungi diversity