The video explains the concept of evolution, defined as a change in the gene pool over time. It uses the example of red hair to illustrate how gene frequencies can remain stable or change, leading to evolution. The 'Five Fingers of Evolution' mnemonic helps remember the five processes that cause evolution: small population size, non-random mating, mutations, gene flow, and natural selection. Natural selection is unique as it leads to adaptation, making organisms better suited to their environment. The video also distinguishes between microevolution, small changes within a species, and macroevolution, which can lead to new species over time.

Discuss the significance of the thumb in the context of natural selection.

Explain how red hair can be considered an adaptation.

What is microevolution and how does it relate to macroevolution?