5.1.2
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.
1Cell Biology
1.1Introduction to Cells
1.2Ultrastructure of Cells
1.3Membrane Structure
1.4Membrane Transport
1.5The Origin of Cells
2Molecular Biology
2.1Water
2.2Carbohydrates & Lipids
2.3Proteins
2.4Enzymes
2.5Structure of DNA & RNA
2.6DNA Replication, Transcription & Translation
2.7Cell Respiration
2.8Photosynthesis
3Genetics
3.1Genes
3.2Chromosomes
3.3Meiosis
3.4Inheritance
3.5Genetic Modification & Biotechnology
4Ecology
4.1Species, Communities & Ecosytems
4.3Carbon Cycle
5Evolution & Biodiversity
5.1Evidence for Evolution
5.2Natural Selection
5.3Classification of Biodiversity
6Human Physiology
6.1Digestion & Absorption
6.2The Blood System
6.3Defence Against Infectious Disease
6.5Neurons & Synapses
7AHL: Nucleic Acids
7.1DNA Structure & Replication
7.2Transcription & Gene Expression
8AHL: Metabolism, Cell Respiration & Photosynthesis
8.1Metabolism
8.2Cell Respiration
9AHL: Plant Biology
9.1Transport in the Xylem of Plants
9.2Transport in the Phloem of Plants
9.3Growth in Plants
10AHL: Genetics & Evolution
10.1Meiosis
10.2Inheritance
10.2.1Linked Genes
10.2.2Sex-Linked Genes
10.2.3Non-Nuclear Inheritance
10.2.4Chi-Squared Test
10.2.5End of Topic Quiz - Inheritance
10.2.6IB Multiple Choice - Non-Mendelian Genetics
10.2.7Introduction to Non-Mendelian Inheritance
10.2.8Extended Response - Inheritance
10.2.9Grade 4-5 (Scientific Practices) - Inheritance
11AHL: Animal Physiology
11.1Antibody Production & Vaccination
11.3The Kidney & Osmoregulation
Jump to other topics
1Cell Biology
1.1Introduction to Cells
1.2Ultrastructure of Cells
1.3Membrane Structure
1.4Membrane Transport
1.5The Origin of Cells
2Molecular Biology
2.1Water
2.2Carbohydrates & Lipids
2.3Proteins
2.4Enzymes
2.5Structure of DNA & RNA
2.6DNA Replication, Transcription & Translation
2.7Cell Respiration
2.8Photosynthesis
3Genetics
3.1Genes
3.2Chromosomes
3.3Meiosis
3.4Inheritance
3.5Genetic Modification & Biotechnology
4Ecology
4.1Species, Communities & Ecosytems
4.3Carbon Cycle
5Evolution & Biodiversity
5.1Evidence for Evolution
5.2Natural Selection
5.3Classification of Biodiversity
6Human Physiology
6.1Digestion & Absorption
6.2The Blood System
6.3Defence Against Infectious Disease
6.5Neurons & Synapses
7AHL: Nucleic Acids
7.1DNA Structure & Replication
7.2Transcription & Gene Expression
8AHL: Metabolism, Cell Respiration & Photosynthesis
8.1Metabolism
8.2Cell Respiration
9AHL: Plant Biology
9.1Transport in the Xylem of Plants
9.2Transport in the Phloem of Plants
9.3Growth in Plants
10AHL: Genetics & Evolution
10.1Meiosis
10.2Inheritance
10.2.1Linked Genes
10.2.2Sex-Linked Genes
10.2.3Non-Nuclear Inheritance
10.2.4Chi-Squared Test
10.2.5End of Topic Quiz - Inheritance
10.2.6IB Multiple Choice - Non-Mendelian Genetics
10.2.7Introduction to Non-Mendelian Inheritance
10.2.8Extended Response - Inheritance
10.2.9Grade 4-5 (Scientific Practices) - Inheritance
11AHL: Animal Physiology
11.1Antibody Production & Vaccination
11.3The Kidney & Osmoregulation
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