Big History: The Big Bang, Life on Earth, and the Rise of Humanity

Lecture 13: Darwin and Natural Selection

Why were these ideas so shocking in Victorian Britain? First, they implied

that all species are related. Perhaps humans were related to apes—or even to

plants and bacteria! In class-conscious Britain, this was a serious problem.

Second, the idea of natural selection implied that complex organisms such as

human beings could be created by blind, statistical processes acting over huge

periods of time. Natural selection (“Darwin’s dangerous idea,” as philosopher

Daniel Dennett has called it) seemed to leave no room for a divine creator.

This terri¿ ed Darwin’s wife, Emma, who feared her husband’s impiety

would ensure that they were separated in the afterlife! A third consequence

was that biological change was endless, because environmental change

ensured that adaptation would continue forever. This meant there were no

perfect organisms, despite the claims of some contemporaries that humans

(particularly British humans) were clearly the “¿ ttest” of all organisms.

We have summarized Darwin’s idea of natural selection. But what evidence

is there that Darwin was right? The next lecture describes why Darwin’s idea

remains at the center of modern biological thought. Ŷ

Christian, Maps of Time, chap. 4.

Mayr, One Long Argument.

Darwin, On the Origin of Species.

Eldredge, Darwin.

1. What was the crucial insight that allowed Charles Darwin to solve the
   problem of adaptation?


2. Why do so many people still ¿ nd Darwin’s solution to the riddle of
   adaptation unpalatable?

Essential Reading

Supplementary Reading

Questions to Consider