Tag Archives: Evolution

Commentary

Three logical prerequisites for biological evolution to work

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Hummingbird in flight
Hummingbird in flight

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 (phyla) to another body plan (phyla) in any peer-reviewed paper. 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. When I question people in the arts who accept Darwinism, they seem to be terribly disinterested in the details, and just want to jump to the conclusion shared by the smart people without thinking hard about all the steps in between. That’s intellectually lazy. The same thing happens with global warming with the non-scientists – they are more concerned about jumping to the “smart people” position, so you think that they’re smart. They aren’t really interested in hearing both sides, or looking at the evidence. I think people need to take it slow and look at the evidence, instead of deciding what to believe based on how other people perceive them. No need to rush to agreement to build up your self-esteem without doing the hard work first.

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

News

New study: rising oxygen levels rejected as explanation of Cambrian explosion

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Apologetics and the progress of science
Apologetics and the progress of science

So, just to refresh everyone, the Cambrian explosion was an event that occurred about 543 million years ago. In a very short period of time, less than 10 million years, probably 3-5 million, all of the major animal body plans emerged.

Here’s what the Cambrian explosion looks like:

Cambrian Explosion
Cambrian Explosion

The Darwinian theory says that there should be precursors to all of the new phyla that appear. But we have never been able to find any precursors. We’ve been looking in the fossil record for the slow transition from simple life to complex life that Darwin predicted, but we’ve never been able to find anything that explains the sudden emergence of the body plans in the Cambrian explosion.

There is no known naturalistic explanation for the rapid emergence of these “phyla”. But, naturalists were holding out hope that maybe a sudden rise in the level of oxygen might have “triggered” the required increase in complexity.

This is from Science Daily.

Excerpt:

Oxygen is crucial for the existence of animals on Earth. But, an increase in oxygen did not apparently lead to the rise of the first animals. New research shows that 1.4 billion years ago there was enough oxygen for animals — and yet over 800 million years went by before the first animals appeared on Earth.

Animals evolved by about 600 million years ago, which was late in Earth’s history. The late evolution of animals, and the fact that oxygen is central for animal respiration, has led to the widely promoted idea that animal evolution corresponded with a late a rise in atmospheric oxygen concentrations.

“But sufficient oxygen in itself does not seem to be enough for animals to rise. This is indicated by our studies,” say postdoc Emma Hammarlund and Professor Don Canfield, Nordic Center for Earth Evolution, University of Southern Denmark.

[…]The new study is published in the journal Proceedings of National Academy of Sciences.

[…]The results differ from other studies and raise several questions, such as: Why then did animals rise so late in Earth’s history?

“The sudden diversification of animals probably was a result of many factors. Maybe the oxygen rise had less to do with the animal revolution than we previously assumed,” says Hammarlund.

Now look here. I don’t see how a rise in oxygen level can create new body plans. Body plans are written in sequences of symbols – in proteins and DNA. I can no more believe that a rise in oxygen levels could create new animal body plans than I could believe that raising the level of oxygen in a computer lab could explain the new code that is being written by the software engineers. Body plans are information, and new body plans require new information. Information comes from software engineers – intelligent agents – not from rising oxygen levels.

In any case, the hypothesis was falsified. It isn’t the first time a naturalistic hypothesis for the Cambrian explosion was shot down (see below) and it won’t be the last.

Related posts

Polemics

Can naturalism account for the origin of the 20 amino acids in living systems?

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Do the Miller-Urey experiments simulate the early Earth?
Do the Miller-Urey experiments simulate the early Earth?

The origin of life

There are two problems related to the origin of the first living cell, on naturalism:

  1. The problem of getting the building blocks needed to create life – i.e. the amino acids
  2. The problem of creating the functional sequences of amino acids and proteins that can support the minimal operations of a simple living cell

Normally, I concede the first problem and grant the naturalist all the building blocks he needs. This is because step 2 is impossible. There is no way, on naturalism, to form the sequences of amino acids that will fold up into proteins, and then to form the sequences of proteins that can be used to form everything else in the cell, including the DNA itself. But that’s a topic for a separate post.

Today, let’s take a look at the problems with step 1.

The problem of getting the building blocks of life

Now you may have heard that some scientists managed to spark some gasses to generate most of the 20 amino acids found in living systems. These experiments are called the “Miller-Urey” experiments.

The IDEA center has a nice summary of origin-of-life research that explains a few of the main problems with step 1.

Miler and Urey used the wrong gasses:

Miller’s experiment requires a reducing methane and ammonia atmosphere,11, 12 however geochemical evidence says the atmosphere was hydrogen, water, and carbon dioxide (non-reducing).15, 16 The only amino acid produced in a such an atmosphere is glycine (and only when the hydrogen content is unreasonably high), and could not form the necessary building blocks of life.11

Miller and Urey didn’t account for UV of molecular instability:

Not only would UV radiation destroy any molecules that were made, but their own short lifespans would also greatly limit their numbers. For example, at 100ºC (boiling point of water), the half lives of the nucleic acids Adenine and Guanine are 1 year, uracil is 12 years, and cytozine is 19 days20 (nucleic acids and other important proteins such as chlorophyll and hemoglobin have never been synthesized in origin-of-life type experiments19).

Miller and Urey didn’t account for molecular oxygen:

We all have know ozone in the upper atmosphere protects life from harmful UV radiation. However, ozone is composed of oxygen which is the very gas that Stanley Miller-type experiments avoided, for it prevents the synthesis of organic molecules like the ones obtained from the experiments! Pre-biotic synthesis is in a “damned if you do, damned if you don’t” scenario. The chemistry does not work if there is oxygen because the atmosphere would be non-reducing, but if there is no UV-light-blocking oxygen (i.e. ozone – O3) in the atmosphere, the amino acids would be quickly destroyed by extremely high amounts of UV light (which would have been 100 times stronger than today on the early earth).20, 21, 22 This radiation could destroy methane within a few tens of years,23 and atmospheric ammonia within 30,000 years.15

And there were three other problems too:

At best the processes would likely create a dilute “thin soup,”24 destroyed by meteorite impacts every 10 million years.20, 25 This severely limits the time available to create pre-biotic chemicals and allow for the OOL.

Chemically speaking, life uses only “left-handed” (“L”) amino acids and “right-handed” (“R)” genetic molecules. This is called “chirality,” and any account of the origin of life must somehow explain the origin of chirality. Nearly all chemical reactions produce “racemic” mixtures–mixtures with products that are 50% L and 50% R.

Two more problems are not mentioned in the article. A non-peptide bond anywhere in the chain will ruin the chain. You need around 200 amino acids to make a protein. If any of the bonds is not a peptide bond, the chain will not work in a living system. Additionally, the article does not mention the need for the experimenter to intervene in order to prevent interfering cross-reactions that would prevent the amino acids from forming.

Usually when you hear the origin of life debated, they sort of skirt about the problem of where the amino acids come from, but there is no reason not to make that an issue. The naturalist has to explain how the first living cell could come about naturalistically.

Positive arguments for Christian theism