Animal Kingdom

1
Animal Kingdom

• Vertebrates

2
Vertebrate History

• Overview Half a Billion Years of Backbones
• By the end of the Cambrian period, some 540
  million years ago
• An astonishing variety of animals inhabited
  Earths oceans
• One of these types of animals
• Gave rise to vertebrates, one of the most
  successful groups of animals

3
Whats with the Name?

• The animals called vertebrates
• Get their name from vertebrae, the series of
  bones that make up the backbone

4
Vertebrate Diversity

• There are approximately 52,000 species of
  vertebrates
• Which include the largest organisms ever to live
  on the Earth

• Vertebrates have
• Vertebrae enclosing a spinal cord
• An elaborate skull
• Fin rays, in aquatic forms

5
Fish The First Vertebrates

• The earliest fossils are from 500 million years
  ago.
• Highly evolved/adapted for living in water
  environments.

6
Water Presents Unique Challenges

• How to move around
• How to get air
• How to float
• How to sense what is around me

7
Movement

• Fish Shape- Fish are streamlined to minimize
  resistance.
• Fish Skin- It is slimy, covered with mucous
  secretions to reduce friction
• Fish Paddles- The fins of fish allow for movement.

8
Gas Exchange

• Water has 2.5 the free oxygen as air.
• Gills- Need to be very efficient at gas exchange.
• They are composed of lots of tiny folds called
  lamellae.
• Capillary beds move in opposite direction to
  water flow allowing for countercurrent exchange
  of oxygen.

9
Gas Exchange (Cont.)

• Water needs to be constantly moved over the
  gills.
• Ram Ventilation- Adaptation of swimming with
  mouth open.
• Operculum- A gill covering that can pump in water.

10
How to float

• Floating/Sinking is dependent on density.
• FloatLess dense than water
• SinkMore dense than water
• 4 Methods for floating
• Low density oils
• Low density bones
• Fins
• Pneumatic sacs- lungs or swim bladder that can be
  filled with air.

11
Sensory Functions

• Fish have eyes, nose, and ears
• Additionally
• Lateral line system- collection of sensory nerves
  that run in a line along the sides of fish.
• Can sense currents or predator/prey movements.
• Electroreception-Detection of electrical fields
  from nerves and muscles of the other organisms.

12
Class Agnatha

• (a- not, without gnatho jaw)
• The lampreys.
• Dont have jaws, often parasitic
• The most primitiveform of fish with a true
  vertebrate

Lamprey
13
Two Classes of Jawed Fish

• Class Osteichthyes Bony Fish
• Class Chondrichthyes Cartilage Fish
• Two different responses to selection pressures.
• Each have advantages and disadvantages.

14
Class Chondrichthyes Cartilage Fish

• (chondro cartilage ichthys fish)
• Sharks and rays
• They have a cartilage skeleton, not bone.
• Their backbone extends into their caudal fin

15
Class Osteichthyes Bony Fish

• (osteo bone)
• Bony fish.
• 24,000 Species
• Operculum
• Swim bladder or lungs
• 90 of membersfertilize externally.
• Lots of eggs

16
Class Chondrichthyes Cont.

• Advanced Electroreception
• They also fertilize internally.
• Produce fewer eggs, less young tend to die.
• Lack operculum, lungs, and swim bladder

17
Class Amphibia

• (amphibia living a double life)
• They were the first land vertebrates.
• Most either go back and forth from land to water
  or undergo metamorphosis.

18
Amphibian History

• Early fossils of now extinct amphibian ancestors
  date back 400 million years.
• Modern amphibians represent 3,000 species on all
  continents except antartica.
• There are three Orders
• Caudata
• Anura
• Gymnophiona

19
Order Caudata

• Salamanders and newts
• Possess a tail throughout life, little leg
  development, most have internal fertilization,
  live in forest floors and caves constant moisture
  and temperature.
• Larvae similar to adult but smaller with external
  gills and a tail fin.

20
Order Gymnophiona

• Caecilians
• (Rare)160 Species in tropical regions
• Worm-like burrowers that feed on invertebrates in
  the soil.
• Retractile tentacles between their eyes and
  nostrils may give sense of smell.
• Skin covers eyes (probably blind)
• Internal fertilization

21
Order Anura

• 4,000 species of frogs and toads
• Can live in most aquatic environments
• Adults highly developed hind limbs no tails
• Larval stages (tadpoles) have tails, no limbs,
  and are omnivores.
• Primarily external fertilization
• Frog and toad-less scientific toad normally
  means dry and warty skin and are more terrestrial
  than frogs.

22
Skin

• Skin is crucial for gas exchange 30-90.
  (cutaneous respiration)
• Buccal pump-when mouth and pharynx muscles push
  air into lungs.
• Skin also used to regulate temperature
  (exothermic)
• Skin also regulates water (osmoregulation)

23
Nervous System

• Amphibians have highly developed eyes.
• Used for catching prey.
• Nicitating membrane used for keeping eye clean
  and refracting light.
• Anura has developed hearing for sensing prey and
  mating calls.

24
Population Decline

• Amphibian populations declining around the world.
• Larval stages highly sensitive to environment
• pH changes (acid rain)
• UV light (depleted ozone)
• Habitat destruction (human overpopulation)

25
Class Reptilia

• (reptili creeping)
• Dinosaurs (dino terrible ), snakes, turtles,
  crocodiles, and lizards.
• Reptiles have scales and are dry to the touch.
• Reptiles are exothermic (exo out, outside),
  they maintain body temperature through external
  means such as sunning on a rock or seeking
  shade.

26
Class Reptilia(Cont.)

• Dry skin with epidermal scales
• Skull with one surface point touching vertebrate
• Respiration via Lungs
• Internal Fertilization
• True amniotic egg-not only resistant to drying,
  but hard leathery shell and yolk for nutrients.
• Water conserving Kidneys

27
Reptile Diversity and Lineage

• There are 17 Orders of Reptiles, however only 4
  still contain living members.
• Some of the now extinct lineages have given rise
  to Dinosaurs, Birds, and even Mammals.
• The evolutionary advancements of reptiles allowed
  future species to be independent of water
  environments and live exclusively on land.

28
Classification of Living Reptiles

• Class Reptilia
• Order Testudines
• Order Crocodylia
• Order Sphenodontida
• Order Squamata
• Suborder Sauria-The Lizards
• Suborder Serpentes-The Snakes
• Suborder Amphisbaenia-Worm Lizards

29
Order Testudines (Turtles)

• There are approximately 300 species
• They are characterized by bony shell, limbs that
  join the ribs, and keratinized beak instead of
  teeth.
• Lay eggs, but dont protect or provide parental
  care
• Long time to Mature (Up to 8 years)
• Long life span (For some 100 years)

30
Order Crocodylia (Crocodiles)

• 21 species that were derived from archosaurs
  (like dinosaurs).
• Unique skull openings in front of eye, triangular
  eye sockets, laterally compressed teeth.
• Swallow prey whole
• Lay eggs but display parental care and nesting.

31
Order Sphenodontida (Tuataras)

• Two surviving species.
• Look like lizards but are far different, have
  characteristics of 200 million year old fossils.
• There teeth characteristics and structure are
  different from reptiles.
• Asymmetrical organisms do not develop complex
  communication, sensory or motor functions.
• Live in remote islands off of New Zealand

32
Order Squamata

• By far the most diverse and numerous Orders of
  Reptiles.
• Divided into 3 Suborders
• Lizards
• Snakes
• Worm Lizards

33
Suborder Sauria (The Lizards)

• 4500 Species of Lizards
• Have 2 pairs of Legs
• Very Diverse
• 3 cm to 3 m in length
• Some lay eggs, some dont
• Camoflauge
• Long Tongues
• 2 are venomous

34
Suborder Serpentes (The Snakes)

• 2900 Species (Most not dangerous 300 ven.)
• How many people die each year of snake bites?
• More than 200 vertebrate and ribs for flexibility
• Upper and lower jaws open independently
• Eye differences between lizards and snakes
• Thin elongated body has resulted in loss of lung
  and kidney (1 of them)

35
Suborder Amphisbaenia-Worm Lizards

• 135 Species
• They are limbless burrowers
• Distinguished from all other vertebrates by the
  presence of 1 tooth in upper jaw
• Can move forward or backward in burrows and feed
  on small insects.
• Also lay eggs.

36
Reptile Adaptations

• Reptiles are the first vertebrates to live
  exlusively on land.
• Many adaptations to not only survive, but
  flourish
• Reptilia-Dry skin with scales, lungs, specialized
  kidneys, internal fertilization and amniotic eggs.

37
External and Locomotion

• Skin has no respiratory function.
• All reptiles shed the outer layer of their skin
  periodically, called ecdysis.
• Bones have higher density (more ossification)
• Ribs and vertebrate are more numerous and
  flexible allowing for movement.
• Autotomy-Tail loss that allows lizards to escape
  from a predators grasp. Later regenerated.

38
Nutrition and Digestion

• Most reptiles carnivores few turtles are omni or
  herbivores.
• Lizards have sticky far reaching tongues for
  catching prey. Chamelion tongue exceeds body
  length.
• Jaw in snakes are loosely attached and can open
  independently of each other. Great for
  swallowing prey
• Venom is secreted from modified salivary glands
  called fangs. It contains mixture of neurotoxins
  (respiratory paralysis) and hemotoxins (destroys
  blood vessels).

39
Circulation, Gas Exchange and Temperature
Regulation

• Bigger and longer bodies means the need for
  higher blood pressure to provide blood to all
  parts.
• Can migrate together in hibernaculums.
• Many reptiles can control blood flow.
• Oxygen conservation
• Temperature regulation

40
Nervous System

• Highly developed nervous system allows for
  special adaptations that fit each species role.
• Pit Organs-Heat sensitive organs that can detect
  hidden warm blooded prey.
• Parietal Eye-Found in some reptiles (tuataras)
  and is a photoreceptor for detecting light.
• Sea Turtles-Can detect magnetic field and return
  to breeding grounds that are 3,000 km away and 15
  years old.
• Jacobson or vomeronasal organ-Organs that provide
  a highly advanced sense of smell. Work in
  conjunction with the forked tongue of squamates.

41
Excretion and Water Regulation

• Reptiles have metanephric kidneys. They are
  specialized to reduce water loss. (More blood
  filtering units called nephrons)
• In fact, uric acid is secreted in paste like form
  as waste.
• When available reptiles store large quantiites of
  water under skin and in bladder.
• Many lizards have salt glands under eyes to
  secrete salt.

42
Reproduction

• Internal fertilization
• True amniotic egg-Resistant to dessication and
  has a hard shell with yolk.
• Sperm storage-Some female reptiles can store
  sperm for 4-6 years until conditions are good for
  offspring.
• Parthenogenesis-Very special kind of reproduction
  in which one parent produces genetically
  identical offspring. Six species of lizards one
  of snakes. No males found in population.

43
Class Aves

• (avi a bird) is the birds.
• Key characteristic of birds feathers.
• Birds bones are light weight for flight.
• Birds are endothermic (endo within, inner)
  they control their body temp-erature from
  within.

44
Class Aves (The Birds)

• What makes something a bird?
• Bill No teeth
• Light and Hollow Bones
• Endothermy
• Appendages modified as feathered wings
• Flexible Neck
• 8500-10,000 Species (27 Orders)

45
Birds Reptiles By Another Name?

• Lots of similarities between reptiles and birds
• Structural Single point of articulation between
  skull and vertebrae, one ear ossicle, lower jaw,
  and other skeletal similarities.
• Physiological Nucleated rbcs, similar liver and
  kidney functions.
• Behavioral Nesting and care for young
  (Crocodylia)

46
So Where Did Birds Come From?

• Ancient Archosaurs-lineage shared by dinosaurs
  and crocodiles.
• Looks like more closely related to dinosaurs.
• Fossil evidence points to dinosdozens of fossils
  were found bearing feathers.
• Theropods specifically these were bipedal dinos
  like T-Rex.

47
Archaeopteryx Ancient Bird????

• Illustration from the fossils found of this
  ancient bird/reptile. It was initally called the
  link between reptiles and birds, but this is very
  controversial. Fossils date back to 150 million
  years. Picture on page 343 of book.

48
Bird Feathers What are they good for?

• Today Flight Originally Not Flight
• Early fossils with feather had too dense of bones
  and wrong shapes for flight.
• They were probably used for
• Insulation/Temperature Regulation
• Water repellency
• Courtship
• Camoflauge
• Balancing Devices

49
Bird Feathers

• Flight Provide lift and insulation
• (High temperature necessary for high metabolic
  rate)
• Courtship, Waterproofing, balance, etc.
• 2 Broad Types of feathers
• Pennaceous Feathers
• Plumulaceous Feathers
• Preening of feathers is essential-keeps them
  clean, rub oil for waterproofing, and zip back
  together for flight.
• Feathers molt as well.

50
Skeleton and Muscle

• Head is modified to function as hands
• Skull meets backbone at one point and neck is
  very flexible.
• Teeth have been replaced by a bill.
• Bones themselves are lightweight with tiny
  hollows throughout.
• Flight muscles can contract quickly and fatigue
  slowly because of lots of mitochondria that make
  ATP
• Interestingly, domestic chickens are bred
  together for more white meat muscle which is
  good to eat, but poor for flight because of low
  mitochondria and vascularization.

51
Bird Nutrition

• Birds have crazy high metabolisms and need to
  eat a lot!
• Hummingbird wings 80 bps
• Robins Heart rate 600 bpm
• Bill and tongue are highly adapted for their
  niche (role)
• Eagle for tearing prey
• Woodpecker for tapping into trees
• Humminbird tongue unrolls to get into flower

52
Bird Digestion

• Many birds have a crop, which is a storage pouch
  in the esophagus. Allows them to digest in
  safety or store to feed young.
• Stomach has two parts
• Proventriculus (glandular stomach)-secretes
  digestve enzymes.
• Ventriculus (gizzard)-muscular wall to crush
  seeds.

53
Circulation and Gas Exchange

• Heart Relatively large for size, rapid heart
  rate, and unlike reptiles complete separation of
  oxygenated and non-oxygenated blood.
• Respiratory System Most advanced of all
  tetrapods
• 2 Cycle inhale/exhale, which maximizes oxygen
  intake.
• Explains how birds fly at high altitudes.

54
Thermoregulation

• Maintain a body temperature of 38-45 Celsius.
  (100-113 F)
• Feet of a bird have no feathers and poor blood
  supply. They can drop to near freezing.
• During flight large amounts of heat are
  generated. Birds will pant and open mouths to
  allow for evaporative heat loss.

55
Sensory Functions

• Vision is important to birds
• Have a unique double focusing mechanism.
• Can change the curvature of their lens and cornea
  to allow for maximal focus on prey during flight.
• Have nicitating membrane
• Poor sense of smell
• Similar hearing to human

56
Excretion

• Birds need to conserve water, much like reptiles.
• Secrete Uric Acid
• Store and reabsorb water in bladder
• Have salt glands for salt secretion
• This can allow sea birds to drink salt water.

57
Bird Mating

• Bird reproduction is complex, it involves
  establishing territory, finding mate,
  constructing nests, incubating eggs, and feeding
  young.
• All birds are oviparous
• Birds only chase off others of the same species
  during territory establishment, threats are
  frequent, but fights rare.
• A clear territory ensures safe nesting, food
  supply and better chance of offspring survival.

58
Bird Mating Behaviors

• Most birds are monogamous for a breeding season
  and some for life. However, polygynous and
  polyandrous occurs depending on species.
• Monogamy-Having one mate.
• Polygynous-Having more than one female.
• Polyandrous-Having more than one male.
• Each has its own advantages and disadvantages.
  Which gives most young? Which gives best chance
  of survival?

59
Bird Nesting

• Nesting behavior is species specific.
• Eggs need to be incubated for 10-80 days.
• Collection of eggs and young for a bird is called
  a clutch.
• Lifespan in captivity is 20 years and on average
  in wild most birds live 1 to 2 years.
• Offspring come in two forms
• Altricial-Entirely dependent on parents.
• Precocial-Young are alert and lively at hatching.
  Normally covered in feathers.

60
Migration and Navigation

• Birds will migrate long distances in order to
  avoid environmental extremes.
• Non-stop fliers will store 50 of their body
  weight in fat.
• Normally involves north and south movement.
• Migration occurs due to species specific
  physological cues and environmental cues.
• Most common cue is period of daylight.
• They navigate based on visual, auditory and
  sometimes magnetic cues.

61
Class Mammalia

• (mamma, mammil teat, nipple)
• Mammals.
• Key characteristics presence of fur/hair and
  mammary glands, which produce milk for young.
• Most mammals bear live young

62
When/How Did Mammals Arise?

• The Tertiary period about 70 million years ago.
• This coincided with the reptile extinctions
  (dinosaurs).
• Dinosaurs being gone opened the door to lots of
  niches.food and habitat sources not being used.
• May have initially been nocturnal to avoid
  potential large reptile predators.
• Living at night would have made endothermy very
  important.

63
Class Mammalia

• Mammary Glands
• Hair
• Most have live birth
• Diaphragm
• Well developed ear
• Heterodont
• Four Chambered Heart
• Well developed cerebral cortex
• Sweat and scent glands
• Endothermy

64
3 Main Infraclasses

• Monotremes-They are oviparous and have a cloaca.
  Ex. Duck Billed Platypus
• Cloaca-Common opening for digestion, reproduction
  and excretion.
• 6 Species found only in Australia and New Guinea
• Metatheria-Viviparous with a primitive placenta.
  Young are born early and carried in a pouch.
  (Marsupials)
• Eutheria-Complex placenta young are well
  developed before birth. (Placentals)
• By far the most numerous and diverse group.
• All the Orders we are about to talk about fall
  under this Infraclass

65
How Well Adapted Are Mammals?

• Mammals are naturally found on every continent
  except Antartica.
• This means we have mammals that can live in the
  cold, heat, dry, wet, forest, and plains.
• We have limbs that with claws, hooves, wings, or
  flippers.

66
Mammalian Skin, A Hairy Situation

• Hair is a derivative of the epidermis and is
  unique to mammals.
• An animals coat is called pelage.
• Hair is used for temperature regulation, sensory
  perception,
• and camoflauge.

67
External Adaptations (Cont.)

• Claws are present in mammals.
• They are used for motion or defense.
• They have evolved for each species purpose
  hooves and nails

Lechiens Feet (thats why he wears those big
shoes!)
68
Glands, a Stinky Situation

• Scent/Musk Glands-Found around the face, butt and
  feet. Secrete pheromones involved in defense,
  sex, and territorial behaviors.
• Do Humans have pheromones?
• Sebaceous glands-Secrete oil for hair
  waterproofing and lubrication.
• Sudoriferous glands-Sweat glands for temperature
  regulation.
• Mammary glands-Function in female to provide
  young with food and antibodies.
• Advanced form of parental care.

69
Mammalian Skull and Teeth

• Scientists can tell mammal skulls from reptiles
  from the jaw bone.
• In reptiles the jaw joins with two small bones at
  the rear, but for mammals they are gone and it
  joins in just one spot.
• Mammals have up to 4 kinds of teeth
• Incisors In front for gnawing.
• Canines Tearing
• Premolars Chewing
• Molars Used for grinding
• The number of each kind of teeth can help
  classify a mammal. Ex. Human 2,1,2,3 Beaver
  1,0,1,3
• If you knew an animal was 1, 0, 2, 5 what do you
  probably know about that animal? Or 3, 3, 1, 0?

70
Digestion

• Each mammal species has uniquely adapted
  digestion for its diet.
• Herbivores Eat lots of cellulose, which is not
  normally digestable to our bodies.
• They have a cecum A specialized pouch that
  stores bacteria that break down the cellulose.
• Cow, deer, and sheep have 4 stomachs each at
  different stages of fermentation.

71
Circulation and Gas Exchange

• Like birds we have a 4 chambered heart that
  separates oxygenated and non oxy. blood.
• The best advancement for mammals is the exchange
  of air, nutrients, and waste to/from fetus
  through the placenta.
• Fetal and maternal blood vessels are intimately
  close, but no mixing occurs.
• Unlike reptiles or birds, the diaphragm separates
  chest and abdominal cavity and is a muscle that
  contracts for mammal breathing

72
Endothermy

• Most mammals live in environments that require
  both heating and cooling.
• Heating
• Shivering Involuntary muscle contractions.
• Cell Metabolism Breakdown of food.
• Cooling
• Sweating Evaporative cooling on skin.
• Blood flow Blood can be directed to surface.

73
Nervous System

• Highly evolved senses and brain
• 3 Middle ear ossicles
• Vision-Controlled by Rods(light, no color) and
  Cones (color)
• Most mammals have poor color vision and lots more
  rods than cones.
• How does this support the idea that early mammals
  were nocturnal?

74
Excretion and Territory

• Mammals have metanephric kidneys, but secrete
  urea (more watery than reptile uric acid)
• Lots of mammals use urine to mark territory,
  access sexual readiness, and even fitness of
  individuals.

75
Behavior

• Behavior is important for mammal survival.
• Grooming-Reinforces social bonds and prevents
  disease.
• Sounds-Can warn of predators or invoke breeding
• Bristling of fur-Serve as warning.

76
Reproductive Cycles Strategies

• Most mammals have a set time in which their eggs
  are mature and ready for fertilization.
• This reproductive cycle is called the estrus
  cycle.
• Monestrus-A single time of year. Ex. Bears
• Diestrus-Twice a year. Ex. Domestic Dog
• Polyestrus-Many times. Ex. Rats every 4 days
• Two strategies
• Delayed fertilization-Storing sperm and waiting
  to fertilize.
• Embryonic dispause-Fertilization has occurred but
  embryo development is temporarily paused.
• Why are these two strategies a good thing for
  some mammals?