Transcript EVOLUTION IN ACTION

EVIDENCE OF
EVOLUTION
CHAPTER 15-2
EVOLUTION
DEFINED…
Evolution is a process of
gradual modifications
EVOLUTION
DEFINED…
Evolution is a process of
gradual modifications
Darwin called this descent
with modification
COMMON ANCESTOR
Many animals and plants shared common
ancestors and deviated from that common
ancestor overtime.
Organism 1
Ancestor
Organism 2
7 LINES OF
EVIDENCE
SUPPORTING THE
THEORY OF
EVOLUTION
1. PALEONTOLOGY
Fossils provide geologic
evidence of evolution
•
Fossils in older layers are more
primitive than those in the
upper layers
1. PALEONTOLOGY
Fossils provide geologic
evidence of evolution
•
•
•
Fossils in older layers are more
primitive than those in the
upper layers
Shows that life has become
more complex.
Shows that life on earth has not
always been the same
Transitional Species:
• Direct descendants of modern day
species
• Fossil record contains the intermediates
• Descent with modification states that newer
species are modified versions of older species
2. VESTIGIAL
STRUCTURES
• Remnants of organs or structures that had a
function in an early ancestor.
2. VESTIGIAL
STRUCTURES
• Remnants of organs or structures that had a
function in an early ancestor.
• Shows that these organisms are
descendants from organisms that used
them.
Ex: Whale hind leg bones
3. HOMOLOGOUS
STRUCTURES
Body parts that are similar in
structure, but may have
different functions
3. HOMOLOGOUS
STRUCTURES
Body parts that are similar in
structure, but may have
different functions
• Indicating at some point way in
the past they did the same job
and came from a common
ancestor
FEATHERS
4. ANALOGOUS STRUCTURES
Same functions but
different development
4. ANALOGOUS STRUCTURES
Same functions but
different development
• ex. a butterfly wing and a
bat wing
• Indicates that populations
evolve to be better suited
to the environment
5. BIOGEOGRAPHY
• Geographical distribution of living creatures.
5. BIOGEOGRAPHY
• Geographical distribution of living creatures.
• Similar species are found in similar places
showing common ancestry.
(divergent evolution)
Ex: marsupials in Australia
6. EMBRYOLOGY
• Some stages of
embryo development
of different
organisms are
similar
• Shows common
ancestry
7. BIOLOGICAL
MOLECULES
DNA  RNA Proteins
•Similar proteins means similar DNA
7. BIOLOGICAL
MOLECULES
DNA  RNA Proteins
•Similar proteins means similar DNA
•The more similar proteins means they
share a recent common ancestor
WHALE VIDEO
http://www.teachertube.com/viewVideo.php?title=Whale_evol
ution&video_id=65653