Chapter 2 - Darwinian Scheme of Evolution

Notes for Understanding Evolution - Chapter 2

Click link to return to Biology 409 Schedule
or back to Chapter 1 or ahead to Chapter 3

General guide on these review questions here

PBS Website Link

Objectives:

a) What observations and ideas were important to Darwin’s insight as to how "adaptations" in nature might be explained (i.e., by his notion of natural selection)?
b) Can you describe natural selection, starting with observations about natural populations and ending with Darwin’s proposed mechanism of change?
c) What is the distinction between evolution and natural selection?

Introduction

Featured Scientist: Charles Robert Darwin

source of image

Links: 1 - 2 - 3 - 4

RQ2.1: How did Charles Lyell's book on geology have an important role in Darwin's understanding of evolution?

RQ2.2: Give an example of how biogeography (comparison of the geographic distribution of species) had an important role in Darwin's understanding of evolution?

I. Mechanism of Evolution

Key Terms: descent with modification (Darwin's terms for his notion of "evolution"), artificial vs. natural selection

II. Darwin's Natural Selection

RQ2.3: How did Thomas Malthus' book on economics have an important role in Darwin's understanding of evolution?

Featured Scientist: Alfred Russel Wallace

source of image

Links: 1 - 2 - 3 - 4 - 5 - 6

RQ2.4: Explain the notion of natural selection, incorporating all of the following: 1) variation; 2) heredity; 3) potential reproduction; 4) competition

III. Differential Reproduction

RQ2.5: How is fitness defined by biologists?

RQ2.6: What two words best sum up Darwin's notion of natural selection?

IV. Evolution Defined

Key Terms: individual, population, evolution (Note that the definition of evolution presented here is one type of evolution: anagenesis; later we will discuss another type known as cladogenesis or speciation.)

RQ2.7: Does evolution refer to individuals or populations?

Click link to return to Biology 409 Schedule
or back to Chapter 1 or ahead to Chapter 3