A reader asks: Evolutionists argue that DNA is evidence that we all came from a common ancestor. We argue that it is evidence of a common designer (one God). I don't know enough about biology, but maybe Diane Eager could look at this question - I was wondering if another reason for all plants and animals having DNA is that they can become other animals and humans' food. That is our body will digest an animal, or fruit and vegies (which all have DNA) but it will not digest a rock (no DNA). Could that be part of the reason?

Answer from Diane Eager: There is a grain of truth in this idea, but it is not so much DNA but the building blocks that make it. Our digestive systems break down large molecules like DNA, carbohydrates and proteins to smaller molecules such as purines, glucose, amino acids, etc. These are small molecules, but are more complex than simple molecules found in rocks, sand and dust. Even though we do need simple minerals in our diet, e.g. salt, it would take a lot of energy if our bodies had to make proteins etc. out of things like carbonates, nitrates, phosphates, etc. Therefore, the Lord made plants to build the biological molecules out of these raw materials, using sunlight as the power source. It is a marvellous system the more you think about it.

Evidence News 5 August 2009
