A Very Bad Case For Design

Creationists have a lovely way of shooting themselves in the foot by taking the worst possible example to try and justify their case. This recent comment (found here) exemplifies this beautifully

“To know something and to assume to know something is different. Example, one lives alone and he/she goes home and just saw that dinner table is served with all kinds of fruits and food. Now I am thinking and conclude that somebody prepared all the food and served it. But Steve and Dawkins ASSUME that all the food came up there by chance and Luck. This world with their related seasons which act like a servant is a very big food stale where we eat all the food according to the our body needs. Vitamin C or D etc. Who created human beings created the soil where all food fruits and veggies can grow and who created the soil, created the sunlight and rain that all cooperate with each other to serve us.”


Here is the real problem (other than the obvious misunderstanding of evolution and the absurd analogy): Our ancestors once made vitamin C for themselves. They did not need to ingest it. We lack a functional gene for an enzyme called L-gulonolactone oxidase. This forms the last step in the production of ascorbate (vitamin C) from glucose. We do however contain a pseudogene for this enzyme, which does not function because of acquired mutations. This presents a problem for the creationist.

The problem is that design requires being made to fulfil a purpose. Creationism boils down to an organism must be designed because it fulfils a purpose and all its parts are created to fit together to perform that purpose (that and a lack of imagination). So, here we have something that has no purpose and its only reasonable explanation is that it was present in a functional form in our ancestors (it probably became inactive about 40 million years ago).

Reductionism is a common theme in biology. If we don’t need a gene, there is no selective advantage in keeping it. There may even be a slight energetic advantage in losing it. Genes are lost through random mutations, and there are many examples of this occurring. It is not just the L-gulonolactone oxidase gene that we have lost; mice and humans have about 200 “genes” for a family of olfactory (scent) genes called the V1r family. Mice have about 160 functional ones. Humans have only 5! Whales and dolphins have no functional members. The non functional ones have become fossilised in our genome; they are slowly decaying. Gene loss is seen at an extreme level in parasites, as their hosts provide much of what they need for them. The record holder is Mycobacterium leprae; it has about 1600 functional genes and approximately 1100 decaying fossil genes.

It is not just genes that are lost, but structural features too. Examples include the toes of horses that can be seen gradually disappearing in successive rock layers, our appendix and the limbs of proto-snakes (Figure 1).

An interesting recently described example of this is the eyes of blind cave fish. It was found that functional eyes could be restored by interbreeding populations isolated in different caves. This is important. The fact that they have been isolated from each other means that the blindness evolved independently in the different populations. The fact that cross breeding some populations restored sight in the offspring means that different genes are responsible for the blindness in different populations of the same species – surely design would mean this should not be possible – as the perfect designer would chose the one way to make these fish blind – unless of course he wanted to make it look like evolution – just like chromosome 2.

One final point on vitamin C: inerrant biblical literalists believe that all animals were intended to eat plants and fruit (genesis 1:29-30). However, these foods contain vitamin C, so our ancestors would not need genes to synthesise it.

As one can see below, the teeth of Carcharocles megalodon are beautifully designed to peel grapes (sarcasm in case creationists are reading).