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
Ancestor Common ancestor Organism 1 Organism 2 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 on earth has not always been the same
Transitional Species: Descent with modification states that newer species are modified versions of older species - Fossil record contains the intermediates
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
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. Ex: marsupials in Australia
6. Embryology Some stages of embryo development of different organisms are similar Shows common ancestry
7. Biological Molecules Similar proteins means similar DNA DNA RNA Proteins Similar proteins means similar DNA
7. Biological Molecules Similar proteins means similar DNA 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