Default publications post thumbnail

Scientists Uncover a Good Purpose for Long-Lasting Pain in Animals

Who trusted God was love indeed
And love Creation’s final law
Tho’ Nature, red in tooth and claw
With ravine, shriek’d against his creed

— Alfred, Lord Tennyson, In Memoriam A.H.H.

If God exists—and if He is all-powerful, -knowing, and -good—why is there so much pain and suffering in the world?

Perhaps nothing epitomizes the problem of pain and suffering more than the cruelty observed in nature. When asked about the elegant designs that characterize biological systems, Charles Darwin retorted, “What a book a devil’s chaplain might write on the clumsy, wasteful, blundering, low and horridly cruel work of nature!”

This enigma keeps many skeptics and seekers from the Christian faith and even troubles some believers. Yet, researchers from the US have recently uncovered an important function for long-lasting pain in animals, signifying that the suffering these creatures experience can have a purpose.1

In animals (and humans), injury can lead to long-lasting discomfort, whereby repeated exposure to pain-producing stimuli causes an increasingly amplified response well after the injury has healed. (This phenomenon is called nociceptive sensitization.) Biomedical researchers have long regarded nociceptive sensitization as maladaptive because, in humans, anxiety is associated with it. For a skeptic, the amplified response to pain in animals seems senseless, exacerbating the problem of pain and suffering. But is it so senseless after all?

A collaborative team of researchers (from the University of Texas, George Mason University, and the Marine Biological Laboratory in Woods Hole, MA) recently studied nociceptive sensitization in squid and concluded that heightened sensitivity to pain helps these creatures avoid predation. Squid are an ideal laboratory model because they undertake a well-defined sequence of defensive behaviors when threatened by a predator.

When threatened, previously injured squid (that had fully recovered from their injury) reacted sooner than squid that had not been injured. However, the previously injured squid displayed a slower response to predatory threats when the scientists used anesthetic to block pain immediately after injury and, thus, prevent nociceptive sensitization from developing.

Because nociceptive sensitization is widespread, it likely serves a similar benefit among other animals, as well. These results indicate that pain (and the concomitant suffering) plays an important role in enhancing animals’ survivability following an injury and recovery. This insight (and others) indicates that the pain and suffering in the natural realm is not necessarily incompatible with God’s existence and His goodness. It can serve a good purpose.

  1. Robyn J. Crook et al., “Nociceptive Sensitization Reduces Predation Risk,” Current Biology 24 (May 19, 2014): 1121–25.