Concepts of Progress and the Tree of Life in Biology

Abstract: The view that biological evolution is progressive, trending toward improvement, has been debated for over a century. Ideas of progressive evolution were primarily driven by cultural views involving social progress, technology, or other non-naturalistic presumptions. Though occasionally debated, these tendencies in the field began to wane from open discussion in scientific writings in the mid-20th century. A key metaphor in evolutionary biology, the evolutionary Tree of Life, rose to prominence over this period and has been a significant component of biological research since its inception with Darwin's Origin of Species. The reconstruction and interpretation of the Tree of Life, connecting all species on earth, living and dead, is one of the fundamental goals of the biological sciences. Here, I discuss how concepts of progress persist in how we analyze and discuss evolution and the Tree of Life. I also discuss how these ideas can have consequences for how both scientists and the public study and interpret the Tree of Life.