Understanding Evolution

Misconceptions about natural selection and adaptation
by the Understanding Evolution team

Natural selection is a powerful process: it produces amazing adaptations (such as the "leaf-disguise" of the katydid shown below) and helps us understand much of what we observe in the natural world — but natural selection is often misunderstood. Frequently, the process is misconstrued as one that simply grants a species any trait that it might need for survival. However, as we will see, natural selection has its limitations, and many characteristics of organisms can be better understood with a more realistic view of the process.

A katydid's
leaf-like appearance is an adaptation that helps protect it from predation
A katydid's leaf-like appearance is an adaptation that helps protect it from predation.

In this article, we will explore these key questions:
  • What are some common misconceptions about the process of natural selection?

  • Why are those views of the process inaccurate?

  • Why might natural selection not have removed all deleterious alleles from a population?

  • What aspect of natural selection is non-random and how does this affect the direction of evolution?

  • What sort of traits are adaptations, and what sorts of traits are not?

  • What is the "neutral theory?"


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Katydid image © Greg Neise, GE Neise Digital Communication.

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