4.4 Evolution in Action: Past and Present

By the end of this section, you will be able to:

• Identify the major contributors to evolutionary theory and their specific theoretical contributions and historical context.
• Explain the theory of evolution and how it applies to the understanding of human origins.
• Identify the key differences between Linnaean classification and phylogenetics.
• Define key evolutionary processes such as genetic drift, allopatric speciation, etc.

Contemporary biological anthropologists utilize an evolutionary perspective. This means that the principles of evolution are used to understand how and why living organisms, including people, thrive in almost every environment on Earth. More specifically, natural selection is accepted as the guiding force that shapes why living things are the way they are. Out of all the possible variations of beings competing for the same resources on Earth, those that prospered were the ones better suited to their environments than all other competitors. The principles of evolution and natural selection will be discussed in some detail in the next few sections, but it is important to establish at this early point that this chapter relies on the foundational assumption that natural forces are the only forces directing the development of life on Earth.