Fundamental to the understanding of life is the study of physiology. Physiology is that branch of biology which describes the functions of the various organs and tissues that make life possible. All the separate organ systems perform different functions that are required for life to exist, e.g., respiration, circulation, digestion, detoxification, excretion, metabolism, etc.

Without all of the systems working constantly, consistently, efficiently, and effectively, life would cease. Together, they are necessary and sufficient to sustain the life of the individual. Because life is all about survival, correct? According to Charles Darwin, organisms are here solely on the basis of their ability to survive, with natural selection eliminating those unable to prevail against their more fit competitors.

A Unique Organ System

And yet… Astonishingly, there is one unique organ system that actually detracts from the chances of survival of even the fittest individuals. One organ system that makes survival less likely, even to the point of seriously endangering the life of the individual. Writing here this morning, biologist Jonathan McLatchie detailed one part of it.

That system is the reproductive system. In order to survive in the wild, an organism has to acquire food, conserve energy, find a safe niche, and avoid predation, injury, or mishap. However, reproduction requires that an organism give up food, expend energy, and dispense with safety by engaging in risky behaviors. All these activities actually decrease the odds of individual survival.

So, Darwin’s theory of natural selection really is not about survival of the fittest, but survival of those best at reproduction. He characterized this as “reproductive selection.” But he was not referring to the dangers of reproduction at all. He was referring rather to the ability of competing males to acquire breeding privilege.

But Therein Lies a Paradox

Why should an individual organism devote itself to something other than itself? If organisms are really just blindly generated collections of molecules, why would these “molecular aggregates” struggle for life, and even much more than that, risk their own life for the sake of offspring?

As always, the perennial answer to such questions comes back to purpose. As I have mentioned repeatedly in previous posts here on the science of purpose, life itself is nothing if not purpose-driven.

And this purposive intentionality, which extends all the way up from the DNA to the cell to the organ to total body physiology, culminates in the most purposeful action in all of life, renewal by reproduction. Because, in the words of St. Thomas Aquinas, “All things are ordered to their end.”