Evolution

Because of the incessant interplay of chance mutations and environmental circumstances in determining the course of natural selection, no two biospheres could have the same history. The entire cloud of vital dust forms a huge cosmic laboratory in which life has been experimenting for billions of years. What it may have produced challenges imagination. The Earth's biodiversity, staggering as it is, may represent only a small sample of the diversity of life throughout the cosmos.
		p. 293
Christian de Duve	Vital Dust: Life as a Cosmic Imperative Basic Books, 1995