Evolution and Biodiversity

1
Evolution and Biodiversity

• Chapter 4

2
Core Case Study Life on Earth

• Uniquely suited for life
• Temperature range
• Liquid water
• Gravitational mass
• Oxygen
• Organisms contribute to relatively consistent
  planetary conditions resilient and adaptive
• Biodiversity and sustainability

3
The Right Mix of Conditions
Fig. 4-1, p. 63
4
4-1 What Is Biological Evolution and How Does It
Occur?

• Concept 4-1A The scientific theory of evolution
  explains how life on earth changes over time
  through changes in the genes of populations.
• Concept 4-1B Populations evolve when genes
  mutate and give some individuals genetic traits
  that enhance their abilities to survive and to
  produce offspring with these traits (natural
  selection).

5
Theory of Evolution

• 4.7 billion years
• Explains why life so diverse
• Supported by fossils, chemical analysis of
  primitive rock, DNA, and ice cores

6
Fossilized Skeleton of a Cenozoic Herbivore
Fig. 4-2, p. 65
7
Population Changes over Time

• Populations evolve by becoming genetically
  different
• Genetic variability mutation

8
Natural Selection

• Genetically favorable traits to survive and
  reproduce
• Trait heritable and lead to differential
  reproduction
• Faced with environmental change
• Adapt
• Migrate
• Become extinct

9
Coevolution

• Changes in gene pool of one species lead to
  changes in gene pool of the other
• Bats and moths

10
Science Focus How Did We Become Such a Powerful
Species?

• Key adaptations also enabled us to modify
  environment
• Evolved very recently
• Technology dominates earths life support systems
  and NPP

11
4-2 How Do Geological and Climate Changes Affect
Evolution?

• Concept 4-2 Tectonic plate movements, volcanic
  eruptions, earthquakes, and climate change have
  shifted wildlife habitats, wiped out large
  numbers of species, and created opportunities for
  the evolution of new species.

12
Plate Tectonics

• Locations of continents and oceans determine
  earths climate
• Movement of continents allow species to move and
  adapt
• Earthquakes and volcanoes affect biological
  evolution

13
Movement of Continents
14
225 million years ago
135 million years ago
65 million years ago
Present
Fig. 4-3, p. 67
15
Stepped Art
Fig. 4-3, p. 67
16
Earths Long-term Climate Changes

• Cooling and warming periods affect evolution
  and extinction of species
• Five mass extinctions
• Eliminated half of the earths species
• Many theories why this occurred
• Opportunities for the evolution of new species

17
Northern Hemisphere over 18,000 Years
18
18,000 years before present
Modern day (August)
Northern Hemisphere Ice coverage

Fig. 4-4, p. 67
19
4-3 What Is an Ecological Niche?

• Concept 4-3 As a result of biological evolution,
  each species plays a specific ecological role
  called its niche.

20
Unique Roles for Species

• Generalist species
• Specialist species
• Specialists prone to extinction giant panda

21
Specialized Feeding Niches in Birds
22
Ruddy turnstone searches under shells and
pebbles for small invertebrates
Herring gull is a tireless scavenger
Avocet sweeps bill through mud and surface water
in search of small crustaceans, insects, and seeds
Brown pelican dives for fish, which it locates
from the air
Dowitcher probes deeply into mud in search of
snails, marine worms, and small crustaceans
Black skimmer seizes small fish at water surface
Louisiana heron wades into water to seize small
fish
Flamingo feeds on minute organisms in mud
Piping plover feeds on insects and tiny
crustaceans on sandy beaches
Oystercatcher feeds on clams, mussels, and
other shellfish into which it pries its narrow
beak
Scaup and other diving ducks feed on
mollusks, crustaceans, and aquatic vegetation
Knot (sandpiper) picks up worms and small
crustaceans left by receding tide
Fig. 4-5, p. 68
23
Science Focus Cockroaches

• Existed for 350 million years 3,500 known
  species
• Highly adapted, rapidly producing generalists
• Consume almost anything
• Endure food shortage
• Survive everywhere except polar regions
• Avoid predation
• Carry human diseases

24
4-4 How Do Extinction, Speciation, and Human
Activities Affect Biodiversity?

• Concept 4-4A As environmental conditions change,
  the balance between formation of new species and
  extinction of existing ones determines the
  earths biodiversity.
• Concept 4-4B Human activities decrease the
  earths biodiversity by causing the premature
  extinction of species and by destroying or
  degrading habitats needed for the development of
  new species.

25
Speciation

• Geographic isolation
• Reproductive isolation
• Millions of years in slow-producing species
• Hundreds of years in rapidly reproducing species

26
Geographic Isolation
27
Adapted to cold through heavier fur, short ears,
short legs, and short nose. White fur matches
snow for camouflage.
Arctic Fox
Northern population
Spreads northward and southward and separates
Different environmental conditions lead to
different selective pressures and evolution into
two different species.
Early fox population
Gray Fox
Adapted to heat through lightweight fur and long
ears, legs, and nose, which give off more heat.
Southern population
Fig. 4-6, p. 70
28
Extinction

• Endemic species vulnerable to extinction
• Background extinction
• Mass extinction
• Balance between speciation and extinction
  determines biodiversity of earth
• Speciation generally more rapid than extinction

29
Extinction through Habitat Loss
Fig. 4-7, p. 70
30
Human Activities and Extinction

• Cause premature extinction of species
• Earth took millions of years to recover from
  previous mass extinctions

31
4-5 How Might Genetic Engineering Affect the
Earths Life?

• Concept 4-5 Genetic engineering enables
  scientists to transfer genetic traits between
  different species a process that holds great
  promise and raises difficult issues.

32
Humans Change Population Genetics

• Artificial selection slow process
• Selective breeding
• Crossbreeding not a form of speciation
• Genetic engineering

33
Results of Genetic Engineering

• Genetically modified organisms (GMOs)
• Gene splitting rapid vs. artificial selection
• Modified crops, new drugs, fast-growing animals

34
Steps in Genetic Engineering (1)
35
Steps in Genetic Engineering (2)
36
Fig. 4-8, p. 72
37
Phase 1 Gene Transfer Preparations
A. tumefaciens
Plant cell
Extract plasmid
Extract DNA
plasmid
Foreign gene if interest
Foreign gene integrated into plasmid DNA, which
can be used as a vector
Agrobacterium takes up plasmid
Phase 2 Make Transgenic Cell
A. tumefaciens (agrobacterium)
Enzymes integrate plasmid into host cell DNA.
Host cell
Fig. 4-8a, p. 72
38
Foreign DNA
Host DNA
Transgenic plant cell
Nucleus
Phase 3 Grow Genetically Engineered Plant
Cell division of transgenic cells
Cultured cells divide and grow into
plantlets (otherwise teleological)
Transgenic plants with desired trait
Fig. 4-8b, p. 72
39
Pros and Cons of Genetic Engineering

• Pros
• May help cure genetic defects
• May improve organisms
• May lead to development of secondary evolution
• Cons
• Ethical issues
• Privacy issues
• Designer babies
• GMO crossbreeding with original organisms

40
Genetically Engineered Mice
Fig. 4-9, p. 73
41
Animation Carbon Bonds
42
Animation Stanley Millers Experiment
43
Animation Evolutionary Tree of Life
44
Animation Stabilizing Selection
45
Animation Disruptive Selection
46
Animation Moth Populations
47
Animation Adaptive Trait
48
Animation Speciation on an Archipelago
49
Animation Evolutionary Tree Diagrams
50
Animation Gauses Competition Experiment
51
Animation Species Diversity By Latitude
52
Animation Humans Affect Biodiversity
53
Animation Habitat Loss and Fragmentation
54
Animation Transferring Genes into Plants
55
Video Ancient Human Skull
PLAY VIDEO
56
Video Asteroid Menace
PLAY VIDEO
57
Video Bachelor Pad at the Zoo
PLAY VIDEO
58
Video Cloned Pooch
PLAY VIDEO
59
Video Creation vs. Evolution
PLAY VIDEO
60
Video Dinosaur Discovery
PLAY VIDEO
61
Video Glow-in-the-Dark Pigs
PLAY VIDEO
62
Video Hsing Hsing Dies
PLAY VIDEO
63
Video Mule Clones
PLAY VIDEO
64
Video New Species Found
PLAY VIDEO
65
Video Penguin Rescue
PLAY VIDEO