There is a Great Diversity of Organisms

1
There is a Great Diversity of Organisms on
Planet Earth.why?
2
What Best Explains Diversity?
I. Special Creation
II. Evolution
Aristotle to Darwin 350 BC to 1800s
Darwin to Present
(A) Each organism originated independently. (B)
Since the time of creation, each organism has
remained the same. (C) All organisms were
created recently.
(A) All organisms originated from common
ancestors. (B) Organisms have and continue to
change over time. (C) Evolution of organisms
began 3.7 billion years ago
3
Aristotles Scale of Nature
Humans
Mammals
Salamanders
Fishes
Crabs
Insects
Special Creation The Creators Plan
Sponges
Plants
Inanimate Matter
4
Carl Linnaeus (1707-1778)

• Believed the Creators Plan could
• be revealed by cataloguing
• organisms according to their
• characteristics

• Founded Systematics Science of
• classifying organisms

5
Comparative Studies of Organisms Escalated in the
early 1800s
Homology Fundamental similarities underlie
obvious physical differences among organisms.
6
Charles Darwin, 1859, Origin of Species, p.434
What could be more curious than that the hand of
a man, formed for grasping, that of a mole for
digging, the leg of the horse, the paddle of the
porpoise, and the wing of the bat, should all
be constructed on the same pattern, and should
include the same bones, in the same relative
positions?
7
Comparative Embryology Homologous Characters
8
Fruit Fly
Why are embryos homologous in structure?
The same set of master regulatory genes regulate
development in diverse organisms
9
Amino Acid Sequence of Pax6 protein
Pax6 mutations cause
Normal eyeless
Eyelessness in flies and fish
Aniridia in mice human (small eyes, absence of
iris)
10
When Pax6 gene from mouse is inserted into fly
cells, extra eyes develop.
11
Structural Homologies are a Product of
Homologous Developmental Programs
Homologous Genetic Programs
12
Why are Similar Organisms Often Clustered
Geographically?
13
Hawaiian Honeycreepers
Geographic clustering suggests evolution from a
common ancestor
14
Is there Evidence that Organisms Change over Time?
Evidence from Living Organisms - Vestigial
Structures - Artificial Selection Evidence from
the Fossil Record - Evolutionary
Intermediates - The Fact of Extinction - The
Law of Succession
15
Evidence for Gradual Evolution
16
Vestigial structures
Nonfunctional Traits That Represent Evolutionary
Baggage
17
Artificial Selection
Humans Have Brought About Organismal Evolution
18
Canine Evolution
100s - 1000s Years Artificial Selection
Ancestral Dog
Canis familaris
Dramatic Evolution Can Occur Over Relatively
Short Periods of Time
1000s - 100,000,000s Years Natural
Selection
Ancestral Canine
19
Artificial Selection Six Different Vegetables
Derived From Wild Mustard
20
Evolutionary IntermediatesDinosaur to Bird
21
Archaeopteryx Fossil
22
Ambulocetus natans (walk-whale swimming)
Basilosaurus isis
Contemporary Whale
23
Evolutionary Intermediates Terrestrial Mammal
to Whale
24
Fish to Terrestrial Tetrapod
25
The Fact of Extinction
Depth in Strata
Upper Strata
Lower Strata
150 Mya
65 Mya
230 Mya
Time of Extinction
26
The Law of Succession
Fossil species found in a given area are
succeeded by similar living species
27
The Earth is Old
28
The Geological Time Scale is Based Upon the
Principles of Relative Dating

• Younger rocks are deposited on top of older rocks
• Lava and sedimentary rocks were originally laid
• down in a horizontal position
• Boulders or cobbles found in a body of rock are
• older than their host rock
• Earlier fossil forms are simpler than more recent
• forms, and more recent forms are most similar
  to
• existing forms.

29
Geologic Column
Earths history as told by rock strata
30
The Geologic Time Scale
31
Radioisotope Decay
1. Find fossil 2. Determine ratio of parent
to daughter atoms 3. Determine number of
elapsed half-lives 4. Estimate age of fossil
32
Geologists Interpret Earths History Through the
Theory of Plate Tectonics
33
80 Ma
70 Ma
Evolutionary History Of Marsupials
60 Ma
50 Ma
34
Geology Provides an Explanation for the
Distribution of Lungfish