Michael Crichton. The The Andromeda Strain (№ 400086)

All people, even the most objective, can't get rid of some innate prejudice when it comes to life challenges. One of those prejudices - the belief that complex life was larger than simple life. On Earth the development of the animal world were always from small to large, from simple to complex. And out of the Earth? In some other places, life might progress in the opposite direction, toward smaller and smaller forms.