I was just watching the first part of the deep ocean episode of The Blue Planet. It is a look at the wide variety of life in the deep ocean. The narrator notes that the attack and defense methods were developed in an "evolutionary arms race". While this sounds good, it fails to note the incredible difficulty of this working in practice. A partial attack or defense method would almost always (if not always) be useless.
We would never look at a computer system that had strong defenses and think it just happened. We also know that those who attack computer systems either use their own intelligence or that of those who designed their tools.
How can we look at the incredible complexity and functionality in life and think it "just happened" with a straight face.