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Evidence of Evolution
1. Fossils & the Fossil Record
2. Homologous Body structures
3. Similarities in Embryology
4. Geographic Distribution of Living
Species
Evidence of
Evolution
Fossil Record provides
evidence that living
things have evolved
Fossils show the history
of life on earth and
how different groups
of organisms have
changed over time
What are Fossils?
 Fossils are the naturally preserved
remains, imprints, or traces of organisms
that lived long ago.
 Fossils provide a record of different
species that lived in the past!
 Paleontologists are scientists who study
fossils!
How do Fossils provide
evidence?
 Fossils can tell us when, where, and how
species lived and the changes that
occurred within the species through
time!
 The location of fossils in sedimentary
rocks determine its age.
Fossil Formation
Primate Skull Fossils
Australopithecus
Homo erectus
Homo sapien
Primate
Brain
Capacity
Primate Bone Fossils
Human Relatives
Australopithecus
afarensis
Homo habilis = handy human
1.5 to 2 mya
Homo erectus
1.6 mya
bipedal
Cro-Magnon
35,000 to 40,000 ya
Neanderthals
35,000 to 100,000 ya
Modern Homo sapien
(fully modern fossils 100,000 ya)
How to determine how
species evolved through
Fossils:
 Look at the preserved remains such as
bone structures, skulls, teeth, bone
position, bone size/shape; imprints
(molds and cast), or traces of the
organisms (carbon remains).
 Compare your findings to the fossil
record and see any similarities with other
organisms both extinct and currently
living on earth.
2. Comparative Anatomy
 Is the study of similarities and
differences in the structures of
organisms.
Comparative
Anatomy
Turtle
Homologous Structures:
 Are parts of
organisms that are
similar in origin and
structure.
 It’s the result of
evolution and can
indicate how closely
two or more species
share a common
ancestor!
Alligator
Bird
Homologous Body Structures
What do you look for in
Homologous Structures?
 Bone structure, location, size and shape are
mainly compared to show relationship
between species. The more similar the
group of species indicates the close
evolutionary relationship!
Vestigial Structures
 traces of homologous organs in other
species
 Organ that serves no useful function
 The pelvis in whales has no function but
its ancestor used it to support hind legs
for walking on land!
13. Evidence of
Evolution
Similarities in
Embryology

In their early
stages of
development,
chickens,
turtles and rats
look similar,
providing
evidence that
they shared a
common
ancestry.
Embryological development
13. Evidence of
Evolution
2. Geographic
Distribution of Living
Species
Similar animals in
different locations
were the product of
different lines of
descent