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Unit 5 EvolutionUnit 5 EvolutionEvidence of Evolution
Evidence 1Evidence 1
Fossil: impression of dead organism made on a surface
Types:Mold: imprint on surface in shape of
organismCast: mold that has been filled
w/minerals to form a model
AustraliaAustralia
Distribution of FossilsDistribution of Fossils
Law of superposition: layers of materials accumulated on the organism
Bottom layer = oldestTop layer = youngest
Succession of formsSuccession of forms
1. Extinction2. Mass extinction: large population
of species disappear in a short period of time
a. Reasons:
Evidence 2Evidence 2
1. Homologous structures: structures that are similar in different species
a. May have common ancestorb. Different functionsc. Example:
Evidence 2Evidence 2
2. Analogous structures: structures of different species that have same function
a. Look similarb. May not have common ancestorc. Example:
Homologous and Homologous and AnalogousAnalogous
Analogous StructuresAnalogous Structures
Evidence 2Evidence 2
3. Vestigial organ: existing structures used by ancestors but not by current species
a. Example:
Evidence 3Evidence 3
Embryology: a. Embryo: first stage of developing
organismb. All vertebrates show similar
features in embryo stage
Evidence 4Evidence 4
Macromolecules:a. Amino Acid and DNA sequences
are similar for certain species-Common ancestor
Patterns of EvolutionPatterns of Evolution
1. Coevolution: different species adapt over time with one another- can be btwn species of mutualism- Example:
CoevolutionCoevolution
Patterns of EvolutionPatterns of Evolution
2. Convergent Evolution: species not closely related adapt similar traits to their environment separately • Analogous structures result• Phenotypes converge• Example:
Patterns of EvolutionPatterns of Evolution
3. Divergent Evolution: 2 or more related species become more different over timea. Different habitatsb. Adaptive radiation: arise from 1
common ancestor1. Example:
c. Artificial selection: diverging due to unnatural occurrences1. Example: