A History of Evolutionary Thought: Understanding Evolutionary Change ch4

A History of Evolutionary Thought: Understanding Evolutionary Change

Chapter 12: The Forces of Evolutionary Change

Learning Objectives (Ch. 12, sections 12.1 & 12.2)

• Early Naturalists' Contributions: Understand how the work of many early naturalists laid the groundwork for the development of evolutionary theory.

• Role of the Fossil Record: Analyze the critical role the fossil record played in shaping the concept of evolution.

• Darwin and Wallace's Inferences: Explain how meticulous observations of nature and extensive voyages of discovery led Darwin and Wallace to infer the principles of natural selection.

• Centrality of Key Concepts: Explain why the concepts of 'descent with modification' and 'natural selection' are fundamental to the theory of evolution.

Early Contributions to Evolutionary Theory

Historically, many scientists contributed to our understanding of evolution, gradually shifting from classical views to modern theory:

• Aristotle (c. $350$ BCE):

  • Core Belief: Believed individuals within a species were essentially identical, and species themselves were unchanging.

  • Concept: This view, often associated with Essentialism, posited that each species possessed an immutable 'essence' or 'type,' with individual organisms being imperfect variations of this ideal.

• Buffon (AD $1749$):

  • Core Idea: Proposed that species could change as they migrated and spread from their original geographical locations.

  • Significance: Conducted scientific studies in comparative anatomy and discussed the idea of a