542 CHAPTER 20The question of progress
Many people who accept evolution conceive it as a purposive, progressive process,
culminating in the emergence of consciousness and intellect. Even some evolu-
tionary biologists have seen in evolution a history of progress toward the emer-
gence of humankind (see [93]).
The word “progress” usually implies movement toward a goal, as well as
improvement or betterment. But the processes of evolution, such as mutation and
natural selection, cannot imbue evolution with a goal. Moreover, progress in the
sense of betterment implies a value judgment, and there is no objective basis for
calling human features better than those of other species. A conscious, reflec-
tive rattlesnake or knifefish (if such existed) would probably measure evolution-
ary progress by the elegance of an animal’s venom-delivery system or its ability
to communicate by electrical signals. But these features are advantageous in the
context of the environment and lifestyle of these organisms. The great majority
of animal lineages—to say nothing of plants and fungi—show no evolutionary
trend toward greater “intelligence” (however it might be defined and measured),
which must be seen as a special adaptation appropriate to some ways of life, but
not others. It is difficult, if not impossible, to specify a universal criterion by which
to measure “improvement” that is not laden with our human-centered values.
Many evolutionary biologists have therefore concluded that we cannot objec-
tively find progress in evolutionary history, except in the sense of context-depen-
dent adaptive improvements [93]. The most characteristic feature of the history of
evolution, rather, is the unceasing proliferation of new forms of life, of new ways
of living, of seemingly boundless, exquisite diversity. The majesty of this history
inspired Darwin to end On the Origin of Species by reflecting on the “grandeur in
this view of life,” that “whilst this planet has gone cycling on according to the fixed
law of gravity, from so simple a beginning endless forms most beautiful and most
wonderful have been, and are being, evolved.”
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