Reading Gregory Benford's novel, Beyond Infinity, I ran across a great quote describing ecosystems. It applies extremely well to software development technologies:
Fast learns, slow remembers. The quick, small things instruct the slow and big by bringing change. The big and slow control by constraint and constancy. Fast gets all the attention; slow has all the power. A robust system needs both.
The novel is so-so, but the ideas are top notch.