Explains that all species are related and gradually change over time due to natural selection.

Natural selection is a mechanism of evolution.

Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success.

This process causes species to change and diverge over time.

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​Theory of evolution

​ Evolution of the Horse

• Fossils

• DNA

• Comparative Anatomy

• Embryology

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What are the evidences of Evolution?

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When comparing living animals to extinct animals (fossils), what can we directly compare?

​ Comparing living animals to fossils

Comparative anatomy is the study of different species of animals in order to understand the adaptive changes they have undergone in the course of evolution from common ancestors.

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Comparative anatomy

​Notice the similar bone structure of each animal skeletal structure although they are adapted to a specific mode of life of the animal.

Review of Homologous and Analogous Structures

​DNA

DNA is evidence of a common ancestor for all of life.

The relatedness of groups of organisms is reflected in the similarity of their DNA sequences.

Embryology, the study of the development of the anatomy of an organism to its adult form.

Provides evidence of a common ancestor due to the relatedness between now widely divergent groups of organisms.

The longer they are similar in development the more related.

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Embryology

Natural Selection:
Organisms that are more adapted to their environment are more likely to survive and pass on the genes that aided their success. This process causes species to change and diverge over time.

An adaptation is a physical or behavioural characteristic that helps an organism to survive in its environment. 

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Natural Selection-Adaptations

 A cladogram is a diagram that shows relationships between species.

These relationships are based on observable physical characteristics.

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​Cladograms

​When Whales Walked

​Watch the video to better understand the evidence to support the evolution of the whale.

This should help you answer the last questions on the study guide.