Science

Wonderful Life: 8 key ideas

by Stephen Jay Gould

The core ideas of Wonderful Life, each in under a minute, written in our own words. Want the full depth? Get the book.

1. IDEA 1 OF 8

   Ancient fossils reveal strange life

   Gould describes the Burgess Shale, a rock formation in Canada that preserves soft-bodied animals from over 500 million years ago.

   These fossils show a surprising variety of body forms. The site is among the richest records of early animal life.

2. IDEA 2 OF 8

   The first study missed something

   Gould describes how Charles Walcott discovered the fossils in 1909 but placed them into familiar groups.

   Later scientists saw that many were far stranger. Walcott's idea of how to sort them was shaped by what he expected to find.

3. IDEA 3 OF 8

   Scientists looked again

   Gould tells how Harry Whittington, Simon Conway Morris and Derek Briggs re-examined the fossils in the 1970s.

   Their careful work revealed unusual body plans. This changed how scientists thought about the first great burst of animal life.

4. IDEA 4 OF 8

   Some animals were truly odd

   Gould describes creatures such as Opabinia, with five eyes and a long nozzle, and Hallucigenia.

   They seemed unlike anything alive today. Such animals suggest that early life tried many designs, and only some of them lasted.

5. IDEA 5 OF 8

   History depends on chance

   Gould argues that evolution is shaped by contingency, chance events that could have turned out differently.

   Survivors were not necessarily better. In his view, luck may have played a larger part in which groups survived than most people think.

6. IDEA 6 OF 8

   Replay the tape of life

   Gould suggests that if the history of life were replayed, the results would be very different.

   Humans might never evolve. In his view, no single outcome was bound to happen, and small changes could send history elsewhere.

7. IDEA 7 OF 8

   Our ancestor was tiny

   Gould describes Pikaia, a small worm-like creature that may be an early relative of animals with backbones.

   Its survival made our existence possible. Gould uses it to show how fragile the line leading to us may have been.

8. IDEA 8 OF 8

   Some later disagreed

   Gould's interpretation has been challenged by other scientists, including Conway Morris.

   The debate about contingency continues. Some scientists believe the fossils fit better into known groups than Gould suggested. Others support parts of his view, so the question is still open.