PBS
Pbs Learning Media: Darwin's Letters: Collecting Evidence
This group of letters is a sample of the extensive correspondence Darwin carried on with a wide group of friends and colleagues as he collected evidence to support his theory of evolution by natural selection. From Charles Darwin's...
PBS
Pbs Learning Media: Darwin's Letters to Lyell
In this letter written to his friend and mentor Charles Lyell less than three weeks after the publication of "On the Origin of Species", Darwin describes the reaction of the great anatomist Richard Owen to his theory. From Charles...
History Tools
History Tools: Charles Darwin on the Origin of Species 1859 [Pdf]
Features excerpts from the introduction and conclusion of Charles Darwin's famous book, On the Origin of Species by Means of Natural Selection.
W. W. Norton
W.w. Norton & Company: Alfred Russel Wallace's Comments on Darwinism
An excerpt from "Darwinism: an Exposition of the Theory of Natural Selection with some of its Applications", by Alfred Wallace. He was a contemporary of Darwin who is credited as the co-developer of the theory of natural selection.
University of California
Ucmp: Are Birds Really Dinosaurs?
A great essay that illustrates how science is done as well as the relationship between dinosaurs and modern birds. Includes a picture to illustrate this concept, and contains many links to related sites.