Evolution in Action: The Incredible Goldfish

Bubble Eye Goldfish
Bubble Eye Goldfish

In Ocean Park in Hong Kong there is a “Goldfish House” which features some 300 different varieties of fish that appear to be creatures from another world. The Red Bubble Eye, for example, has two cheeks that bulge out like huge balloons with a yellow color bridging off from an orange body. The tricolor Dorsal-Finned Bubble Eye looks similar, but it has a large dorsal fin and its body is black and white and it has a long flowing black and white tail. The tricolor Ranchu has a face like a bulldog and a multicolored body and the Black Dragon Eye has two huge eyes that protrude from the body and large, delicate fins. All of these fish that look so different from one another descended from the Prussian carp, also known as Gibel carp, which were raised by Chinese Buddhists in the Tang Dynasty. By the tenth-century these fish which we call “goldfish” were prized as pets.

The Japanese took many of these very different kinds of goldfish back to Japan where raising unusual looking fish became a hobby of many people. By 1850 breeding clubs were formed in the United States and in Great Britain, there is a Goldfish Society with a large number of members. Goldfish have two sets of chromosomes from each parent, which means that mutations are preserved and expressed in many ways. Over 300 varieties exist at the present time.

Our local breeder of goldfish calls this “evolution at its best.” There are practical uses for this hobby. Most of these fish are small–four to ten inches–but there are varieties that grow to 25 pounds. I can remember crappie fishing in the 1960’s with goldfish minnows, which were raised by a fish farm in Martinsville, Indiana. They were effective as bait because of their visibility, but the rapid growth of these fish makes them ideal as a food source in some areas of the world.

Evolution is not a synonym for “man from monkey.” Evolution is a tool for producing new varieties of life which can benefit us in many ways. In the case of the goldfish there is aesthetic value in these changes, but also economic and nutritional value. When young people study biology in high school, they learn about how these genetic processes work and why. The design of the genetic materials that allow all of this is incredibly complex. In the Bible, Jacob used evolutionary change. The flocks of Laban were modified in a beneficial way by Jacob using these same principles. (See Genesis 30.)

All of the goldfish in the world are from the one species. It takes a creative imagination to visualize how some of these strange looking varieties of fish can form, but the changes do not involve adding organs or making massive changes in biological digestive processes.

God is the author of this process, and trying to understand how all of this was designed and how it came to be applied to all the life forms that exist on the earth today is an enthralling field of study for young biology students. Everywhere we look in the natural world we find that a wonder-working hand has gone before. Changes like those shown in the goldfish speak eloquently about how beautiful and creative the genetic design of life can be.
–John N. Clayton © 2017

The Frillfin Goby–A Fish with a Built-in GPS

Frillfin goby

One of the most studied fish in the ocean is a three-inch long shore fish called the frillfin goby (Bathygobius soporator). This little fish has even gotten attention from the New York Times which ran an article about studies by Dr. Jonathan Balcombe on this fish and how it survives (May 15, 2016).

This fish lives in the intertidal zones in the Atlantic Ocean. When the tide goes out, the fish lives in small tidal pools which are isolated and free of the large predatory fish which pose a threat when the tide is in. The problem is that these small pools can be hunting grounds for shorebirds and crabs so sometimes the fish needs to change pools. The goby does this by jumping out of its pool and landing in a nearby pool that offers better protection. The obvious problem with making this jump is knowing where the next pool is to land in it and not on bare rock. In 1971 a study was done at the American Museum of Natural History to see how the frillfin goby learns where to jump and how far to jump to land in the pool. Their conclusion was that the goby swims over the area at high tide and makes a mental map of the topography of the sea-floor. It can use this mental map 40 days later to escape from a predator. Essentially they have a mental GPS that allows them to make what would otherwise be a very dangerous escape.

This is not a chance driven device. Observers did not see any case where the goby missed its pool. The accuracy of the jumping is far beyond chance. This instinctive drive and the biological features that sustain it are an evidence of an intelligence providing for life in every nook and cranny of the world around us. For more information see the Annals of the New York Academy of Sciences 188 (1): 378-392.
–John N. Clayton © 2017