Overview of Animal Diversity

1
Overview of Animal Diversity

• CHAPTERS 32-34

2

• Begin on Chapter 32
• Red points in this power point are vital facts,
  purple is a point to be aware of, and black is
  contextual information.

3
(No Transcript)
4
Some General Features of Animals
Animals are multicellular heterotrophs that are
diverse in form and habitat, are mobile,
reproduce sexually, and have characteristic
embryonic development.
5
The Traditional Classification of Animals
Taxonomists have traditionally created
phylogenies by comparing anatomical features and
embryological development.
6
Kingdom Animalia is traditionally
divided into the Parazoa lack a definite
symmetry and organized tissues. Eumetazoa have
a definite symmetry and organized tissues.
7
The eumetazoan branch is divided into
Radiata and Bilateria -having bilateral
symmetry. Bilateral animals have
cephalization ( a head region)Bilateral animals
further split into groups with and without a body
cavity (coelom). (p. 660)This is a distinction
long used for classification
8
Types of Body Cavitiespage 660

• Acoelomate -no body cavity
• flatworms
• Pseudocoelomate-pseudocoel located between
  mesoderm and endoderm
• roundworms, rotifers
• Coelomate- body cavity completely contained
  within mesoderm
• many members inc Homo sapiens

9
(No Transcript)
10
Protostome/ Deuterostome

• Protostome-
• Blastopore (invagination of blastula) becomes
  mouth
• Deuterostome
• Blastopore becomes anus

11
(No Transcript)
12
Segmentation

• Each segment may have full set of organs
• Life may continue if a segment is injured
• Facilitates more complex locomotion

13
A
See note about Polyphyletic group
14

• 32.3 Acoelomates are solid worms that lack a body
  cavity.
• Flatworms (platyhelminthes), simple body
  structure with ability to regenerate lost parts-
  (page 674)

15

• Pseudocoelomates have a pseudocoel, simple body
  cavity. ( In the pseudocoelomates, circulation
  occurs in the whole body, not in a defined
  circulatory system.
• Nematodes-ex parasitic Trichenella (raw pork)
• Rotifer Feeding

16

• Puzzles related to Animal Evolution
• Origin of sponges?
• The multinucleate hypothesis, polyphyletic origin
  hypothesis, and the colonial flagellate
  hypothesis all try to account for the origin of
  metazoans from single-celled protists.
• See picture on page 656

17
Figure 32.3
Individualchoanoflagellate
Choanoflagellates
OTHEREUKARYOTES
Sponges
Animals
Collar cell(choanocyte)
Other animals
18

• Puzzles related to Animal Evolution
• A large diversity of animal body plans occurred
  around the Cambrian period, with no major
  innovations since. Cause?...
• the emergence of predatory lifestyles or
  geological factors (CO2 sequestered).
• debut of Hox genes within developing animal
  embryos.

19
INVERTEBRATES
20

• Mollusks were among the first coelomates. The
  evolution of a coelom was a significant advance
  in animal body structure because it repositions
  fluid and allows complex tissues and organs to
  develop.

21
Major Classes of Mollusks(677)

• class Gastropoda (snails and slugs)
• class Bivalvia (oysters, clams)
• class Cephalopoda (octopuses, squids, and
  nautiluses).

22
Annelids were the first segmented
animals.Segmented Bodies

• Segmentation was a key transition in animal
  body plans, because similar segments can be
  individually controlled for different functions.
• Tube within a tube body plan. (p. 682- see giant
  earthworm) Locomotion --hydrostatic skeleton
  forces fluid from one segment to the next. Major
  Classes of Annelids
• Polychaeta , Oligochaeta (earthworms), and
  Leeches

23
Lophophorates appear to be a transitional
group. Lophophorates (Ectoprocta group)

• Characterized by a ridge around the mouth bearing
  ciliated, hollow tentacles (lophophore) that
  functions in gas exchange and food collection.
• (pg 667)
• U-shaped digestive system (677)

24
Lophophorates(Ectoprocta)

• Classifying the lophophorates has been difficult.
  Why?
• They share some characteristics with protostomes
  (mouth may form from blastopore, but not always,
  ribosomes usually like protostomes), and others
  with deuterostomes (radial cleavage in most)
• Why does any of this matter?

25
Arthropods are the most diverse of all animal
groups.

• Over two-thirds of all named species on the earth
  are arthropods.

26
arthropod body plan

• Jointed appendages --
• legs, antennae, and mouthparts
• exoskeleton of chitin and protein used for
  protection and water loss prevention,
• most diverse phylum on the planet.
• Arthropods are segmented, with some segments
  fused into functional groups (ex head, thorax,
  abdomen)

27
arthropods

• The exoskeleton is secreted by, and fused
  with, the epidermis, and provides a hard surface
  for muscle attachment. All arthropods have an
  open circulatory system some have adaptations
  such as compound eyes, a respiratory system
  composed of tracheae, and an excretory system
  composed of Malpighian tubules.

28

• What is a soft shelled crab?
• Why must arthropods molt?

29
A Major Group of Arthropods Crustaceans

• Most crustaceans have two pairs of antennae,
  three types of chewing appendages, and various
  pairs of legs. Crustaceans are found in
  marine, freshwater, and terrestrial habitats.

30
Major Classes of Arthropods Arachnids

• Arachnids have a pair of chelicerae (mouthparts),
  a pair of pedipalps (copulatory or pincer
  function), and four pairs of walking legs.

31
Major Classes of Arthropods Centipedes and
Millipedes

• Centipedes and millipedes are made of a head
  region followed by numerous similar segments.
• Centipedes have one pair of legs per segment, and
  millipedes have two pairs per segment.

32
Major Classes of Arthropods Insects

• Class Insecta is the largest group of organisms
  on the planet, living in nearly every possible
  habitat. Most are relatively small, and
  contain three body sections head, thorax, and
  abdomen, with three pairs of legs attached to the
  thorax, and one pair of antennae. Most insects
  have compound eyes.

33
insects

• Many insects undergo either simple or complex
  metamorphosis.
• What are the stages of complete metamorphosis?

34
Complete Metamorphosis in Insecta

• Complete Metamorphosis
• Egg
• Larva
• Pupa
• Adult

35
Echinoderms

• Echinoderms are radially symmetrical as
  adults.Deuterostome Development and an
  Endoskeleton Echinoderms are marine animals
  with hard calcium plates forming a true
  endoskeleton in young individuals.

36
VERTEBRATES
37

• By the end of this PPT, you will know which came
  first, the chicken or the egg.

38

• The Chordates Four features characterize the
  chordates (1) single, hollow nerve cord (2) a
  flexible notochord present at some developmental
  stage (3) pharyngeal pouches connecting the
  pharynx and the esophagus (gill slits in human
  embryos-1 pair remain as eustacian tubes) (4) a
  postanal tail at least during embryonic
  development. (p. 684)

39

• 34.2 Nonvertebrate chordates have a notochord but
  no backbone.The Nonvertebrate Chordates
  Tunicates possess a notochord and a nerve cord as
  larvae, but look at them as adults! (p. 700)
  Lancelets are fishlike marine chordates with a
  permanent notochord running the entire length of
  the dorsal nerve cord. (p. 699)

40
(No Transcript)
41

• The evolution of vertebrates involved invasions
  of sea, land, and air.Characteristics of
  Vertebrates Vertebrates -vertebral column
  instead of a notochord, and a distinct head. (p
  The history of the vertebrates -they invaded the
  sea and then the land. (p. 703)
• Distinction
• A notochord is a flexible rod under the nerve
  cord. A vertebral column is composed of segmented
  vertebrae that enclose the nerve cord.

42
Vertebrates are distinguished from other chordates

• Neural crest
• Internal organs
• Endoskeleton of bone or cartilage for size and
  movement

43

• Fishes Fish were the first vertebrates and are
  the most diverse and successful vertebrate group.
  (p. 690) Key characteristics of fish include a
  vertebral column, jaws and paired appendages,
  gills, single-loop circulation, and nutritional
  deficiencies (they need to eat a nitrogen
  source). (p 707 and circulation
• PPT)

44

• Sharks eventually became dominant sea predators,
  partially due to a skeleton composed of calcified
  cartilage. Sharks were also among the first
  vertebrates to develop teeth.
• What do you know about sharks teeth?
• We will closely examine a shark after AP testing

45

• Bony fish -- ossification provides a strong base
  for muscle attachment and evolved in fresh water.
  (p. 696)
• swim bladder for buoyancy
• a lateral line sensory system (also found in
  sharks, to be seen in lab)
• and a gill cover (operculum) to permit water to
  be pumped over the gills. (pp. 696-697)

46

• Amphibians
• legs
• cutaneous respiration
• lungs, pulmonary veins
• partially divided heart 3-chambered heart
  (711-12 and circulation PPT)
• evolved from lobe-finned fishes.
• Include frogs and toads, salamanders, and
  caecilians (w/o limbs).

47

• Reptiles Key characteristics of reptiles
  include the amniotic egg, dry watertight skin,
  and thoracic breathing (expand ribcage).
• Turtles, lizards and snakes, tuataras, and
  crocodiles. (pp. 714-718)
• What are the components of the amniotic egg?

48
Mudskippers in Fiji!!!
49
Watertight Amniotic Egg

• Amnion- Membrane that surrounds embryo and
  maintains watery environment (portable sea)
• Chorion-Gas exchange
• In bird egg, this membrane is found attached to
  inner shell.
• In mammals, becomes embryos part of the placenta
• Allantois-Helps dispose of nitrogenous waste
  (garbage bag) (forms part of umbilical cord in
  mammals)
• Yolk Sac- Contains fat rich nutrients (develops
  into allantois in mammals)

50
(No Transcript)
51

• Birds Modern birds retain many reptilian
  characteristics, but lack teeth and have
  vestigial tails. They are distinguished from
  living reptiles by feathers and the presence of a
  thin, hollow flight skeleton. (p. 718-720)
• They have a one way air flow through the
  lungs.
• Descended from dinosaurs

52
(No Transcript)
53

• Mammals Hair, mammary glands, a placenta,
  heterodont dentition.
• the ability to digest plant material, keratinized
  hooves, nails or horns,
• and flight capability in bats.

54

• The Orders of Mammals Mammals were not common
  until dinosaurs disappeared. Modern mammals fall
  into one of three categories monotremes,
  egg-laying mammals marsupials, pouched mammals
  and placentals. (721-27)

55

• Evolution among the primates has focused on
  brain size and locomotion.Primates Grasping
  fingers and toes and binocular vision are two
  features that allowed primates to flourish.
  Modern prosimians include lemurs, lorises, and
  tarsiers, while anthropoids include monkeys,
  apes, and humans. - (Zaboomafoo from PBS)

56

• Australopithecines Bipedalism marked the
  beginning of hominid evolution, although the
  reason for such evolution remains controversial.
  (p. 722)
• What are some possible reasons?
• Maybe its just so we can hold hands.

57

• The Genus Homo The first humans (Homo habilis)
  evolved from australopithecine ancestors about 2
  MYA. (p. 724) Homo erectus replaced H.
  habilis, and is believed to have come out of
  Africa. (pp. 724-725)

58

• Homo sapiens is both the only surviving species
  of the genus Homo and the only surviving hominid.
  They are thought to be over 100,000 years old.
  (p. 726) Humans are the only animals that can
  effectively make tools, that have refined and
  extended the ability to use conceptual thought,
  and that can use symbolic language and shape
  concepts and experiences with words. (p. 726)
  but, Think Tank in National Zoo and recent Duke
  University research...

59
Taung Skull2.5 myo Australopithicus africanus
60
Taung Skull Site(near my African village!!!)
61
Human Evolved from Monkeys?

• See page 726, Fig 34.43
• Does this cladogram show that humans evolved from
  monkeys?

62
List major vertebrate developments

• Nerve cord, notochord, pharyngeal slits, tail
• Jaws
• Amniotic egg
• Watertight skin
• Advanced nervous system
• Refined cardiovascular system

63
Major Extinction Events
64
6th Mass Extinction Currently
Page 515 in Campbell 9 and 308 in U D
65
(No Transcript)
66
Geological Time Scale Questions

• Draw the geological time scale indicating the
  eras and periods.
• List the periods that ended with a mass
  extinction.
• Using Campbell 9th, page 521 (and 515), tell what
  major events occurred during each mass
  extinction.
• It will be important to know factors that lead to
  extinction, but not dates or period names.