The Origins of Life ............................................................................

LECTURE

And it’s now very, very clear—it’s been repeated using different gases—

that creating these simple chemicals is really not a huge problem in an

environment without free oxygen.

E

ven the simplest living organisms are extremely complicated, so
explaining how the ¿ rst organisms were created is a tough challenge.
Fred Hoyle (1915–2001), one of the pioneers of modern cosmology,
put it like this:

A junkyard contains all the bits and pieces of a Boeing-747,

dismembered and in disarray. A whirlwind happens to blow

through the yard. What is the chance that after its passage a fully

assembled 747, ready to À y, will be found standing there? (Hoyle,

The Intelligent Universe, p. 19)

Hoyle made this comparison because both Boeing 747s and yeast

cells contain about 6 million parts. Hoyle’s solution to the puzzle of

life’s origins was to argue that life must have evolved somewhere else

in the Universe before arriving on Earth. Yet most modern biologists

are convinced that life did evolve on Earth, and that the idea of natural

selection provides part of the explanation. This lecture summarizes

some of the main ideas of modern explanations of the origins of life

on Earth.

Traditional explanations for the origins of life can be divided into the divine
and the naturalistic. Divine explanations suppose that life was created by a
divine being. As we’ve seen before, modern science excludes such theories
because they beg further questions (who created the creator?) and they
cannot be tested scienti¿ cally. It does not assert that such theories are wrong,
but merely that they cannot be tested scienti¿ cally. Naturalistic explanations
suppose that life can be generated spontaneously from existing materials and
forces. The Greek philosopher Aristotle (384–322 B.C.E.) saw the appearance
of maggots in rotting meat as an example of spontaneous generation.