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
Organism 2
Ancestor
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 STRUCTURESSame functions but different development
4. ANALOGOUS STRUCTURESSame 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_evolution&video_id=65653
