Three logical prerequisites for biological evolution to work

Biologist, blogger and super-mom Lindsay has written a post that explains what supporters of Darwinian mechanisms have to prove in order to explain the origin and diversity of life.

Here are the three things that Darwinists must demonstrate:

  1. It is possible to add biological information.
  2. There are more upward steps than downward steps (or at least a way to get more upward steps than downward steps at least some of the time).
  3. There does exist a gradual genetic pathway that can be climbed in tiny, incremental steps.

So first of all, the main two arguments for intelligent design and against naturalism are the origin of life and the Cambrian explosion. Both involve massive infusions of new biological information. So Lindsay is right to focus on whether Darwinism can add new biological information. But I wanted to focus on number three, because I really think that her post is about the burden of proof on Darwinists more than it is about our burden of proof. And we do need to get used to asking Darwinists for the evidence for their view.

Take a look at the detail on number three:

In order for evolution to be true, not only does information have to be added over time, but each successive change must occur in a living organism and it must be conserved by being passed on to offspring. Thus, the change cannot kill the organism or seriously disable it, or the change will not be passed on. This must be the case for EVERY step in the entire evolutionary sequence, no matter how small. At every step you must have a functional organism. Thus, the changes must be gradual enough that the tiny upward steps (if they exist) can achieve each new level without killing or disabling the organism. To use a simplistic analogy, if one tries to change from one word to another by changing one letter at a time (cat to cot to dot to dog, for example), there must, at every step, be an actual word that can be reached by changing one letter. In the Mount Improbable analogy, this means that there can be no upward jumps in the trail. If the maximum possible upward step is 6 inches, then there can be no 6 foot cliffs along the trail, or even 7 inch steps. If ever there is a step which requires more information than unguided evolution can provide, then evolution is falsified in that instance. It cannot account for the change in information if that is the case.

Now I have never seen a gradual genetic pathway from one body plan to another in any peer-reviewed paper. I am talking about from one phyla to another. What I need to see to believe in the ability of Darwinian mechanisms to drive change from one body plan to another is that sequence of changes at the genetic level. And I don’t just need to see the steps, I need to see the probabilities of getting the correct sequence of changes at the genetic level within the time available by chance. That’s what Darwinists assert in their theory – that’s what they need to prove. Talking about how one creature looks like another creature is irrelevant. My car looks like my Dads car, because we drive the same model, but different model years – and both cars are designed.

When people ask our side for evidence for our claims, we are able to produce the evidence to substantiate our claims, e.g. – cosmic fine-tuning factors or protein sequencing probabilities. I would like to see the other side do the same, and not just tell me a story.

If you are looking to understand what the other side has to prove, and in a concise way, read her post.

2 thoughts on “Three logical prerequisites for biological evolution to work”

  1. I am not sure if this posted or not (since it doesn’t show up as pending) but if it did please disregard or delete the additional post:

    I’ve never found a person who rejected evolution and accurately understood it or the underlying mechanisms. Case in point, the claim that there is no way to add more “information”. This claim was originally that all mutations could do is delete DNA, that all life was being gradually degraded over time from a perfect state. When of course for centuries we’ve known this not to be the case, because (we now know due to things like duplication mutations) DNA can be either added, removed, copied, transplanted, or modified. This is also just common sense because we know someone can, to use an obvious and freakish example, be born not just with fewer digits but also with more digits or a digit in another part of the body or a longer digit or a shorter digit etc, etc. Most mutations are not as severe as a thumb growing out of the forehead, but the idea that mutations only delete “information” is obviously not the case, they also modify and add it.

    The “cambrian explosion” was not so much an increase in information in life as it was an increase in how much of that information was recorded in the form of fossils – it is the period when soft-bodied creatures which do not fossilize well or often began developing structures like bones and teeth and exoskeletons which fossilize easily and commonly, thus it appeared as an “explosion” of life in the way the dawning of the written word would appear as an “explosion” of language, when of course people had spoken languages for thousands of years prior and the only thing new was that we had a record of it. This period also does not, as some creationists still claim, represent the beginning of life on earth.

    As for upward steps vs downward steps, there is no upward or downward since removing a trait is going to be just as useful as adding it in some environment and natural selection does not universally favor either. However the species that tend to be the most complex seem to be the ones with the widest range which have inhabited the most numerous different environments, and the species which appear to be living fossils or primitive forms of modern species are often isolated and shielded from natural selection. It is the same with civilizations, the ones that are the most advanced have had the most contact and competition with their neighbors whereas the ones that have lived in isolation for thousands of years often have stagnated in terms of culture and technology. A civilization would no more develop a nuclear bomb or a stealth fighter if that civilization were not regularly invaded than natural selection would favor something like higher intelligence if a species never left a pond in half a billion years.

    As for a series of intermediates from one body plan to another, those intermediates do exist and you just haven’t been exposed to them. Study the comparative anatomy of different species and you will see that everything in nature is a different version of everything else. How did the heart evolve? Well we have a four-chambered heart, as do all mammals. Reptiles have a three chambered heart, with the exception of alligators/crocodiles which are not true reptiles and are more closely related to pre-dinosaurs – they have a three-chambered heart with a flap that can temporarily turn it into a four-chambered heart during moments of exertion. Amphibians and fish have a two-chambered heart and if you examine crustaceans, some of them have a heart and some don’t. This is just one example, you can find similar patterns throughout nature with every imaginable aspect of human (or other) anatomy. I remember once seeing a creationist say, mockingly that birds couldn’t have evolved from dinosaurs because “I’ve never seen a feather that looked like a scale”. It turns out that feathers and scales are both made of a substance called keratin, which is also what claws (and our claws that we call “fingernails”), fur (and our fur that we call “hair”), and callouses are made of. And the gene that makes the substance in reptiles apparently only suffered one mutation between reptiles, dinosaurs and birds.

    Everything in nature is a different version of everything else. If you want more examples feel free to ask.

    Oh, and here’s a good illustration for the eye:

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    1. I do indeed understand evolution. I have a Master’s degree in Biology from an accredited secular university. I taught college undergraduate biology and anatomy classes until my oldest daughter was born. I know of what I speak.

      I know of no creationist who has claimed that DNA cannot be added. But adding DNA nucleotides doesn’t necessarily add information to the genome. Information is software, not hardware. The nucleotides of DNA are more analogous to hardware. It is the sequence of nucleotides, and what that sequence tells the cell, that forms the software. Just as adding a random string of numbers to a phone book doesn’t add any new information (it doesn’t allow you learn the phone number of any new person), adding nucleotides without adding functionality doesn’t add information.

      So, yes, mutations can add, delete, rearrange, and modify the sequence of nucleotides. That is something we all agree upon. We also know mutations can delete information (by modifying or deleting the nucleotide hardware that transmits it). However, whether or not mutations can add information (usable software for the cell) remains to be seen.

      As for your statement that there is no upward or downward: There has to be an upward and downward overall if you are to get higher organisms (containing more information) from lower organisms (containing less information). Obviously, a single celled bacterium with a single short chromosome and a simple lifecycle contains less information than a multi-celled, intelligent organism with multiple chromosomes and a social structure. How did the latter come to exist from a simpler beginning unless information was, at some point, added to the genome? The information to build hearts and kidneys and brains and lymph nodes and endocrine glands isn’t present in simpler organisms – so how did it come to exist? That is the question. At some point that information had to be added.

      Until one can demonstrate that information can be added AND that it can be added at a greater rate than it is being removed AND that there is a step-by-step pathway to add the information over time without killing the intermediate organisms, the evolutionary sequence is just conjecture. It’s merely lining up existing organisms and imagining a relationship between them based on little more than similarities in their blueprints (which could also be accounted for in other ways, such as a common designer).

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