Liem’s Paradox and God’s Design

People who believe in naturalism face some interesting problems. One of them is the fact that what evolution predicts should happen doesn’t always happen. This phenomenon is known as Liem’s paradox. Let me explain it.

I am reminded of a field trip to the Shedd Aquarium in Chicago when I was in a teacher-training program sponsored by the National Science Foundation. The leader gave us a demonstration of natural selection that was so easy to understand that it could we could use it in teaching low-level biology students the basics of evolution. Three small fish were introduced into a tank containing a northern pike that had not eaten for several days. One was very healthy, one was slightly impaired with several fins missing, and one was severely impaired with most of its fins missing.

We were asked to predict what the pike would do. We all agreed the pike would eat the impaired fish immediately and then the slightly impaired fish and the healthy fish would probably not be eaten. What happened was that the pike chased the healthy fish around and around the tank as we watched for over an hour. The pike never could catch the healthy fish and never ate the other two. There were all kinds of theoretical explanations for what we observed.

Animals are adapted to eat certain foods. Dr. Karel Liem of Harvard University did a study of a fish in Mexico called Minckley’s cichlid. Those fish have highly specialized pebblelike teeth which are perfect for eating the hard-shell snails that are plentiful in their native environment. What Liem discovered was that these fish would swim right past the snails if they could find softer food. They seemed to avoid the food that their bodies had become adapted to eating.

This evolutionary paradox is called Liem’s paradox, and it is seen over and over in nature. Gorillas will walk miles past copious supplies of stems and leaves which is their typical diet, to get soft sugary fruits that are harder to reach and require long walks. Gorillas in captivity will avoid fibrous foods like celery if they are offered sugary, fleshy fruits, even though those fruits are harder to digest and not good for them.

Liem’s paradox is not hard to understand if we believe that God designed animals to live in specific habitats. The design of animals is always to meet the most austere conditions in their environments. In the case of Minckley’s cichlid the fish will always have the snails to fall back on in hard times, but by being diverse in their diet, they save the snails for times when food is not readily available.

In Uganda’s Kibale National Park there are two different species of monkeys–the mangabey monkeys and the red-tailed guenon monkeys. The mangabey monkeys have flat, thickly enameled molars that allow them to crush hard, brittle foods. The red-tailed guenon monkeys have thinner teeth but have come to share the environment with the mangabey monkeys. Both species of monkeys eat the soft fruits and fleshy young leaves that are around them. In 1997 there was a severe drought, and the soft fruit and leaves were no longer available. The mangabey monkeys survived because they could crack seeds and get at hard foodstuffs which they did not eat until they had to. Animals are designed to get through the hard times but will pass up their special adaptions designed for survival so they can eat preferred foods.

We humans do the same thing. There are times when we eat something we may not like in order to survive, but unlike most animals, our bodies are designed to eat just about anything. We need to remember, “I will praise thee, Lord, for I am fearfully and wonderfully made” (Psalms 139:14) when we look at the diversity of stuff to eat in our local supermarket. We are reminded that Liem’s Paradox is only a paradox to those who are committed to naturalism.
–John N. Clayton © 2018