Suppose someone handed you five random playing cards and you wanted to sort them in numerical order. What would you do? Why, you would use the Shell Straight Insertion method of course. Which means you take out the i_th (1st, 2nd, so on) card and place it in order relative to the card next to it. You repeat this until all your cards are in order. It always works. If you follow this procedure, you will have sorted cards in your hand in no time. If you doubt me try it. You’ve probably done it unconsciously if you play cards and you wanted them ordered in your hand. It always works, not because it is a law, but because it’s something even more fundamental. It’s an a priori principle. One can imagine a universe where different laws held, but one cannot imagine a universe where this did not work. This algorithm is based only the properties of integers and what it means to order them. Like sufficient reason, it underlies logic, not the physical facts of the universe. You can imagine a universe where gravity did not exist, but it would be hard to find one in which 2 + 2 did not equal 4.
If you do the sorting algorithm its success is based upon the same coherence principles that structure all logical relationships. Things can go wrong with sorting, certainly, but the problem will be in the application not in the principles that underlie the algorithm.
Evolution by natural selection is also a sorting algorithm based on a priori principles. As philosopher Christian Illies points out and that it is not just a law, it is a deep principle of reason. Let’s be specific. Natural selection requires three things:
1) Variation in traits
2) Selection on trait differences
3) Trait attributes that are inherited by ‘offspring’ from ‘parents’
I’m using quotes because this works whether these are chemicals, digital computer programs, or beans in a jar—anything. Evolution by natural selection is not really in dispute. It is obviously just a sorting algorithm that sorts things based on some selection criteria, usually determined by some environment where the traits vary on how well they reproduce in that environment.
Claims of evolution by natural selection for a population of things are really making the claim that they are just the sort of thing that fits the three criteria above. The algorithm is not in question.
Are the biological creatures of the earth the sort of thing for which the three criteria hold? That is the only empirical fact in question that bears on a demonstration that evolution by natural selection obtains in the natural world. Biologically the answer is a resounding yes. Life on Earth meets all of the criteria for this algorithm to work. The next few posts will explore this in more detail with special attention to the failure of the Creationist stealth move, so called Intelligent Design, to be a science.
Illies, Christian. 2005. Darwin’s a priori insight: The structure and status of the principle of natural selection. In Hösle, V. and Illies, C. Darwin and Philosophy. University of Notre Dame Press. Notre Dame, Indiana.