3.2.2
Evidence for Evolution - Anatomy & Geography
The Evidence for Evolution by Natural Selection
The Evidence for Evolution by Natural Selection
The theory of evolution by natural selection has evidence from multiple scientific fields. This includes geological, molecular, biochemical, and physical evidence.


Anatomy and embryology
Anatomy and embryology
- An example of anatomical evidence for evolution is the presence of structures in organisms that share the same basic form.
- For example, the bones in the appendages of a human, dog, and whale all share the same overall construction resulting from their origin in the appendages of a common ancestor.
- Over time, evolution led to changes in the shapes and sizes of these bones in different species, but they have maintained the same overall layout.
- Scientists call these synonymous parts homologous structures.


Vestigial structures
Vestigial structures
- Some structures exist in organisms that have no apparent function at all, and appear to be residual parts from a past common ancestor.
- These unused structures without function are called vestigial structures.
- Examples of vestigial structures include wings on flightless birds, leaves on some cacti, and hind leg bones in whales.


Geographical evidence
Geographical evidence
- The geographic distribution of organisms on the planet follows patterns that are best explained by evolution in conjunction with the movement of tectonic plates over time.
- Broad groups that evolved before the breakup of the supercontinent Pangaea (about 200 million years ago) are distributed worldwide.
1Unity & Diversity - Molecules
1.1Water
1.2DNA Structure & Replication
1.3Transcription & Gene Expression
2Unity & Diversity - Cells
2.1The Origin of Cells
2.2Introduction to Cells
2.3Ultrastructure of Cells
2.4Cell Division
2.5Structure of DNA & RNA
2.6DNA Replication, Transcription & Translation
2.7Cell Respiration
2.8Photosynthesis
2.9Viruses
3Unity & Diversity - Organisms
3.1Diversity of Organisms
3.2Evidence for Evolution
4Unity & Diversity - Ecosystems
4.1Classification
4.3Evolution & Speciation
4.3.1Evidence for Evolution - Fossils & DNA
4.3.2Evidence for Evolution - Anatomy & Geography
4.3.3IB Multiple Choice - Evidence for Evolution
4.3.4Extended Response - DNA & Evolution
4.3.5Populations
4.3.6Mutations, Genetic Drift, & Gene Flow
4.3.7Speciation
4.3.8Rate of Speciation
4.3.9Allopatric & Sympatric Speciation
4.4Conservation of Biodiversity
5Form & Function - Molecules
6Form & Function - Cells
6.1Membranes & Membrane Transport
6.2Organelles & Compartmentalization
6.3Cell Specialization
7Form & Function - Organisms
7.2Transport
7.3Muscle & Motility
8Form & Function - Ecosystems
8.1Species, Communities & Ecosytems
8.3Carbon Cycle
9Interaction & Interdependence - Molecules
9.1Enzymes
9.2Metabolism
9.3Cell Respiration
10Interaction & Interdependence - Cells
10.1Chemical Signalling
10.2Neural Signalling
10.3Adaptation to Environment
10.4Ecological Niches
11Interaction & Interdependence - Organisms
11.1Integration of Body Systems
12Interaction & Interdependence - Ecosystems
12.1Populations & Communities
12.2Transfers of Energy & Matter
13Continuity & Change - Molecules
13.1DNA Replication
13.2Protein Synthesis
14Continuity & Change - Cells
15Continuity & Change - Organisms
15.1Inheritance
15.1.1Non-Nuclear Inheritance
15.1.2Linked Genes
15.1.3IB Multiple Choice - Non-Mendelian Genetics
15.1.4Extended Response - Inheritance
15.1.5Introduction to Non-Mendelian Inheritance
15.1.6Chi-Squared Test
15.1.7End of Topic Quiz - Inheritance
15.1.8Sex-Linked Genes
15.1.9Grade 4-5 (Scientific Practices) - Inheritance
16Continuity & Change - Ecosystems
16.1Natural Selection
16.2Stability & Change
Jump to other topics
1Unity & Diversity - Molecules
1.1Water
1.2DNA Structure & Replication
1.3Transcription & Gene Expression
2Unity & Diversity - Cells
2.1The Origin of Cells
2.2Introduction to Cells
2.3Ultrastructure of Cells
2.4Cell Division
2.5Structure of DNA & RNA
2.6DNA Replication, Transcription & Translation
2.7Cell Respiration
2.8Photosynthesis
2.9Viruses
3Unity & Diversity - Organisms
3.1Diversity of Organisms
3.2Evidence for Evolution
4Unity & Diversity - Ecosystems
4.1Classification
4.3Evolution & Speciation
4.3.1Evidence for Evolution - Fossils & DNA
4.3.2Evidence for Evolution - Anatomy & Geography
4.3.3IB Multiple Choice - Evidence for Evolution
4.3.4Extended Response - DNA & Evolution
4.3.5Populations
4.3.6Mutations, Genetic Drift, & Gene Flow
4.3.7Speciation
4.3.8Rate of Speciation
4.3.9Allopatric & Sympatric Speciation
4.4Conservation of Biodiversity
5Form & Function - Molecules
6Form & Function - Cells
6.1Membranes & Membrane Transport
6.2Organelles & Compartmentalization
6.3Cell Specialization
7Form & Function - Organisms
7.2Transport
7.3Muscle & Motility
8Form & Function - Ecosystems
8.1Species, Communities & Ecosytems
8.3Carbon Cycle
9Interaction & Interdependence - Molecules
9.1Enzymes
9.2Metabolism
9.3Cell Respiration
10Interaction & Interdependence - Cells
10.1Chemical Signalling
10.2Neural Signalling
10.3Adaptation to Environment
10.4Ecological Niches
11Interaction & Interdependence - Organisms
11.1Integration of Body Systems
12Interaction & Interdependence - Ecosystems
12.1Populations & Communities
12.2Transfers of Energy & Matter
13Continuity & Change - Molecules
13.1DNA Replication
13.2Protein Synthesis
14Continuity & Change - Cells
15Continuity & Change - Organisms
15.1Inheritance
15.1.1Non-Nuclear Inheritance
15.1.2Linked Genes
15.1.3IB Multiple Choice - Non-Mendelian Genetics
15.1.4Extended Response - Inheritance
15.1.5Introduction to Non-Mendelian Inheritance
15.1.6Chi-Squared Test
15.1.7End of Topic Quiz - Inheritance
15.1.8Sex-Linked Genes
15.1.9Grade 4-5 (Scientific Practices) - Inheritance
16Continuity & Change - Ecosystems
16.1Natural Selection
16.2Stability & Change
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