Download Kingdom animalia

Multicellular
life arose over a
billion years ago
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
1
KINGDOM
ANIMALIA
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI OWUSU-DAAKU
2
What Is an Animal?
 Animals
 Are eukaryotic, multicellular, heterotrophic organisms that
obtain nutrients by ingestion
 Digest their food within their bodies
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
3
 Most animals
Haploid
reproduce sexually
and then proceed
through a series of
developmental
stages
 Most animals have
muscle cells and
nerve cells that
control the muscles
Sperm
Egg
2
1
Meiosis
Fertilization
Zygote
(fertilized egg)
Adult
3
Diploid
Blastula
(cross
section)
7 Metamorphosis
Digestive tract
Outer cell
layer
Primitive (ectoderm)
gut
6
4
5
Early
gastrula
Larva
Inner cell layer
(endoderm)
THURSDAY 18TH MARCH
2010
Later gastrula
Opening
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
4
Early Animals and the Cambrian
Explosion
 Animals probably evolved from a colonial protist that
lived in the Precambrian seas
Digestive
cavity
Reproductive
cells
1 Early colony
of protists
(aggregate of
identical cells)
THURSDAY 18TH MARCH
2010
2 Hollow
sphere
(shown in
cross section)
Somatic
cells
3 Beginning of
4 Infolding
cell
specialization
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
5 Gastrula-like
“protoanimal”
Figure 17.4
5
 At the beginning of the Cambrian period, 545 million years
ago, animals underwent a rapid diversification
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
6
Animal Phylogeny
 To reconstruct the evolutionary history of animal phyla,
researchers must depend on clues from comparative
anatomy and embryology
 Four key evolutionary branch points have been
hypothesized
 The first branch point is defined by the presence of true
tissues
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
7
Sponges
Cnidarians
Flatworms Roundworms Mollusks
Annelids
Arthropods Echinoderms
Coelom from
cell masses
Chordates
Coelom from
digestive tube
4
Pseudocoelom
True coelom
No body
cavity
3 Body cavities
Radial
symmetry
Bilateral
2 symmetry
True tissues
1
Multicellularity
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
8
 The second major evolutionary split is based partly on
body symmetry
(b) Bilateral symmetry
(a) Radial symmetry
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
9
 Third, the evolution of
body cavities led to more
complex animals A body
cavity


Is a fluid-filled space
separating the digestive
tract from the outer body
wall
May be a pseudocoelom or
a true coelom
Body covering Tissue-filled
region
(from
(from
ectoderm)
mesoderm)
(a) No body cavity (e.g., flatworm)
Pseudocoelom
Body
covering
(from
ectoderm)
Digestive
tract (from
endoderm)
(b) Pseudocoelom (e.g., roundworm)
Coelom
Digestive
tract (from
endoderm)
Muscle
layer (from
mesoderm)
Body covering
(from ectoderm)
Tissue layer
lining
coelom and
suspending
Digestive
tract (from Mesentery internal
organs
endoderm)
(from
(c) True coelom (e.g., annelid)
mesoderm)
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR.
KOFI OWUSU-DAAKU
10
Fourth, among animals with
a true coelom, there are two
main evolutionary branches,
which differ in embryonic
development
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
11
THE KINGDOM ANIMALIA
Divided into invertebrates
and vertebrates
Invertebrates are animals
without backbones and
represent 95% of the
animal kingdom
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
12
Invertebrates - Sponges
 Phylum Porifera
 Includes sessile animals once
believed to be plants
 Lack true tissues
 The body of a sponge
resembles a sac perforated
with holes
 Draws water into a central
cavity, where food is collected
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
13
Choanocyte
in contact
with an
amoebocyte
Pores
Water flow
Skeleton fiber
Central cavity
Choanocyte
Amoebocyte
THURSDAY 18TH MARCH
2010
Flagella
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
14
Invertebrates - Cnidarians
 Phylum Cnidaria
 Is characterized by organisms with radial symmetry and
tentacles with stinging cells
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
15
 The basic body plan of a cnidarian
 Is a sac with a gastrovascular cavity
 Has two variations: the sessile polyp and the floating
medusa
Mouth/anus
Tentacle
Gastrovascular
cavity
Tentacle
Mouth/anus
THURSDAY 18TH MARCH
2010
Polyp form
Medusa form
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
16
 Examples of polyps are
 Hydras, sea anemones, and
coral animals
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
17
 The organisms we call jellies are medusas
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
18
 Cnidarians are carnivores that use tentacles armed with
cnidocytes, or “stinging cells,” to capture prey
Coiled
thread
Tentacle
Capsule
“Trigger”
Cnidocyte
Discharge of
thread
Prey
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
19
Invertebrates - Flatworms
 Phylum Platyhelminthes
 Is represented by the simplest bilateral animals
 Includes free-living forms such as planarians
Digestive tract
(gastrovascular
cavity)
Nerve cords
Mouth
Eyespots
Nervous tissue
clusters
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
20
 Some flatworms are
parasitic
 Blood flukes are
an example
 Tapeworms
parasitize many
vertebrates,
including humans
Head
Reproductive
structures
Hooks
Sucker
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
21
Invertebrates - Roundworms
 Phylum Nematoda
 Includes the most diverse and
widespread of all animals
 Occurs in aquatic and moist
terrestrial habitats
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
22
 Roundworms exhibit an important evolutionary
adaptation, a digestive tube with two openings, a mouth
and an anus
 A complete digestive tract can process food and absorb
nutrients efficiently
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
23
Invertebrates - Mollusks
 Phylum Mollusca
 Is represented by soft-bodied animals, but most are
protected by a hard shell
 Includes snails, slugs, clams, octopuses, and squids, to
name a few
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
24
 The body of a mollusk has three main parts: a muscular
foot, a visceral mass, and a mantle
Visceral mass
Coelom
Mantle
Kidney
Reproductive
organs
Heart
Digestive
tract
Mantle
cavity
Radula
Shell
Radula
Anus
Gill
Foot
THURSDAY 18TH MARCH
2010
Mouth
Nerve cords
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
Mouth
25
 The three major classes of mollusks are
1. Gastropods, which are protected by a single, spiraled shell
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
26
2. Bivalves, protected by shells divided into two halves
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
27
3. Cephalopods, which may or may not have a shell
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
28
Invertebrates - Annelids
 Phylum Annelida
 Includes worms with body segmentation
Anus
Brain
Main
heart
Coelom
Digestive
tract
Segment
walls
Mouth
Accessory
hearts
THURSDAY 18TH MARCH
2010
Nerve cord
Blood
vessels
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
Excretory
organ
29
 There are three main classes of annelids
1. Earthworms, which eat their way through soil
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
30
2. Polychaetes, which burrow in the sea floor
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
31
3. Leeches, some of which are parasitic
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
32
Invertebrates - Arthropods
 Phylum Arthropoda
 Contains organisms named for their jointed appendages
 Includes crustaceans, arachnids, and insects
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
33
General Characteristics of Arthropods
 Arthropods are segmented animals with specialized
segments and appendages
Cephalothorax
Abdomen
Thorax
Antennae
(sensory
reception)
Head
Swimming
appendages
Pincer
(defense)
THURSDAY 18TH MARCH
2010
Walking
legs
Mouthparts (feeding)
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
34
 The body of an arthropod is completely covered by an
exoskeleton
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
35
Arthropod Diversity
 There are four main groups of arthropods
1. Arachnids, such as spiders, scorpions, ticks, and mites
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
36
2. Crustaceans, such as crabs, lobsters, crayfish, shrimps, and
barnacles
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
37
3. Millipedes and centipedes
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
38
4. Insects, most of which have a three-part body
Head Thorax
Abdomen
Hawk moth
Antenna
Forewing
Eye
Mosquito
Paper wasp
Mouthparts
Hindwing
Grasshopper
Damselfly
THURSDAY 18TH MARCH
2010
Water strider
Ground
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
beetle
39
 Many insects
undergo
metamorphosis in
their development
(a) Larva
(caterpillar)
(b) Pupa
(c) Pupa
(d) Emerging
adult
THURSDAY 18TH MARCH
2010
(e) Adult
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
40
Invertebrates - Echinoderms
 Phylum Echinodermata
 Is named for the spiny surfaces of the organisms
 Includes sea stars, sand dollars, sea urchins, and sea
cucumbers
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
41
 Echinoderms
 Are all marine
 Lack body segments
 Usually have an endoskeleton
 Have a water vascular system that facilitates gas exchange
and waste disposal
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
42
THE VERTEBRATE GENEALOGY
 Vertebrates
 Are represented by
mammals, birds,
reptiles, amphibians,
and fishes
 Have unique features,
including the cranium
and backbone
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
43
Characteristics of Chordates
 Phylum Chordata
 Includes the subphylum of vertebrates
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
44
 Other subphyla include the lancelets and tunicates,
which share four key chordate characteristics
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
45
 The four chordate hallmarks are
 A dorsal, hollow nerve cord
 A notochord
 Pharyngeal slits
 A post-anal tail
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
46
Notochord
Dorsal,
hollow
nerve cord
Brain
Muscle segments
Mouth
Anus
Post-anal
tail
THURSDAY 18TH MARCH
2010
Pharyngeal
slits
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
47
 An overview of chordate and vertebrate evolution
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
48
Precambrian
Cambrian
THURSDAY 18TH MARCH
2010
Paleozoic
Triassic
Tertiary
Cenozoic
Lancelets
Tunicates
Cretaceous
Mesozoic
Jurassic
Agnatha (jawless vertebrates,
such as lampreys)
Permian
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
Mammalia
(mammals)
Aves
(birds)
Reptilia (reptiles)
Amphibia (frogs and
salamanders)
Osteichthyes (bony fishes)
Chondrichthyes (sharks and rays)
Ordovician Silurian Devonian Carboniferous
Eras
Periods
Chordates
Vertebrates
Tetrapods
Amniotes
Feathers
Hair
Amniotic egg
Legs
Lungs or lung derivatives
Jaws
Vertebrae
Ancestral chordate
49
Fishes
 The first vertebrates probably evolved during the early
Cambrian period, about 540 million years ago
 These early vertebrates, the agnathans, lacked jaws
 Agnathans are represented today by lampreys
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
50
 The two major groups of living fishes are the classes
 Chondrichthyes or cartilaginous fishes
 Osteichthyes or bony fishes
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
51
 Cartilaginous fishes have a flexible skeleton made of
cartilage
 Sharks have a lateral line system sensitive to vibrations in
the water
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
52
 Bony fishes
 Have a skeleton
reinforced by hard
calcium salts
 Have a lateral line
system, a keen sense
of smell, and
excellent eyesight
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
53
Amphibians
 Members of the class
Amphibia
 Exhibit a mixture of aquatic
and terrestrial adaptations
 Usually need water to
reproduce
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
54
 Amphibians
 Were the first vertebrates to colonize land
 Descended from fishes that had lungs and fins with
muscles
Lobe-finned fish
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
Early amphibian
Figure 17.34
55
Reptiles
 Class Reptilia
 Includes snakes, lizards, turtles, crocodiles, and alligators
 Can live totally on land
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
56
 Adaptations for living
on land include
 Scales to prevent
dehydration
 Lungs for breathing
 The amniotic egg
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
57
 Reptiles are ectotherms that obtain their body heat from
the environment
 Cold blooded
 Reptiles diversified extensively during the Mesozoic Era
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
58
 Dinosaurs included the largest animals ever to live on
land
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
59
Birds
 Class Aves
 Evolved during the great reptilian radiation of the
Mesozoic era
 Evolved the ability to fly
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
60
 Bird anatomy and physiology are modified for flight
 Bones are honeycombed, which makes them lighter
 Some specific organs are absent, which reduces weight
 A warm, constant body temperature is maintained through
endothermy
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
61
 A bird’s wings
 Illustrate the same principles of aerodynamics as the wings
of an airplane
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
62
Mammals
 Class Mammalia
 Evolved from reptiles about 225 million years ago
 Includes mostly terrestrial organisms
 Two features are mammalian hallmarks
 Hair
 Mammary glands that produce milk and nourish the young
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
63
 There are three major groups of mammals
 Monotremes, the egg-laying mammals, constitute the first
group
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
64
 The second group of mammals, marsupials, are the so-
called pouched mammals

Most mammals are born rather than hatched and are nurtured
inside the mother by an organ called a placenta
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
65
 Eutherians are also called
placental mammals

Their placentas provide more
intimate and long-lasting
association between the mother
and her developing young than
do marsupial placentas
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
66
The Evolution of Primates
 Primate evolution
 Provides a context for understanding human origins
 Primates
 Evolved from insect-eating mammals during the late
Cretaceous period
 Early primates
 Were small, arboreal mammals
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
67
 The distinguishing characteristics of primates were shaped
by the demands of living in trees
 Limber shoulder joints
 Eyes in front of the face
 Excellent eye-hand coordination
 Extensive parental care
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
68
 Apes, the closest relatives
to humans
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
69
The Emergence of Humankind
 Humans and apes have
shared a common
ancestry for all but the
last 5–7 million years
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
70
Anthropoids
Prosimians
Ancestral primate
THURSDAY 18TH MARCH
Evolution from the start to the pinnacle DR. KOFI
2010
OWUSU-DAAKU
Humans
Chimpanzees
Orangutans
Gibbons
Old World monkeys
New World monkeys
Prosimians (lemurs, lorises, pottos, and tarsiers)
Gorillas
Apes
Monkeys
71
Some Common Misconceptions
 Our ancestors were not chimpanzees or any other
modern apes
 Chimpanzees and humans represent two divergent
branches of the anthropoid tree
THURSDAY 18TH MARCH
2010
Evolution from the start to the pinnacle DR. KOFI
OWUSU-DAAKU
72