Wednesday, 1 January 2014

Beneficial mutations and evolution, again.

This year I want to get down to some basics of evolution theory, and try to address the question that bother me so much-why do apparently intelligent people believe that we came from self assembled bacteria by a series of accidents when it is such obvious nonsense? The most obvious answer is that they don’t want to accept the God of the Bible and the claims He makes on their lives. And this applies to many Christians who desire friendship with the world as well as atheists.

The 2 big issues are (1) Is molecules to man evolution well supported by good science or not, and (2) is it consistent with the Christian religion, the ' that was once for all revealed to the saints' (letter of Jude verse 3). They are clearly connected but need in my view to be considered each on its own merits. I share the view of fellow Christians who accept evolution that if science and religion appear to be in conflict, then either the science or religion are wrong (so one or the other should be reviewed and perhaps rejected at the point of disagreement,) or we have misunderstood one or the other and the apparent disagreement is illusory if we can only see it. A lot of misunderstanding creeps in at this point, with Christians who reject evolution theory typically being accused of failing to understand either it or the principles of science. But for today, I want to look at some of the biology.

'Without the variations, natural selection would have nothing to work on'. (Charles Darwin, 'Origin of Species'
I thought I’d start with beneficial mutations since this is absolutely central to the whole modern evolutionary  narrative. in 1859, Darwin speculated that natural selection (i.e. differential survival) acting on beneficial variations was the key to the whole thing, and was the mechanism that brought living things via an unbroken chain of common descent from bacteria to men. He admitted he had no idea as to the cause of the variations, while admitting that 'without the variations, natural selection would have nothing to work on'. We now know that the variations that are central to Darwin's imagined process of descent with modification could ONLY be due to random DNA mutations. The questions then are, (A) can we study random mutations in action today and if so (B) do they demonstrate the characteristics that would support Darwin’s speculations? Or (C) do they falsify evolution's central mechanism by demonstrating that random mutations in fact destroy meaningful DNA information rather than create it?

So I put ‘beneficial mutations’ into the search engine. I found a discussion on Yahoo here where someone asked for examples of beneficial mutations, asserting that sickle cell (the main example I was taught at school for biology) was only beneficial in the sense that cutting your feet off would stop you getting athlete’s foot. The best rated answer was as follows.

Andymanec wrote
I beg to differ, Sickle Cell Anemia *is* a beneficial mutation. Evolution and natural selection comes down to a numbers game. SCA is beneficial when there's only one copy of the gene present, and detrimental when there are two copies present. If two people with SCA had children, those children would have a 25% chance of getting two copies (which would be bad), a 25% chance of not getting a copy (no resistance to malaria), and a 50% chance of getting one copy. When you combine the chances of being immune with the chances of avoiding infection or surviving infection, it outweighs the 25% chance of getting full-blown sickle cell anemia. Thus, it is beneficial in regions where malaria and lack of treatment are problems.
There are a few others. People are being born without some or all of their wisdom teeth. Back in ancient times, an extra set of teeth later in life would have been a huge advantage. Nowadays, our jaws have shrunk and those extra teeth can become impacted. The current state of medicine allows these teeth to be extracted with little risk, so there isn't much pressure to cause the mutation to spread through the population. It's not life-saving, but it's less hassle for those born with it.

We've also found a mutation in a membrane receptor protein that confers resistance to HIV. It's thought to be a remnant from resistance to the bubonic plague or smallpox, and that it prevents HIV from binding to cells. Like the wisdom teeth, there hasn't been recent selective pressure for it to spread throughout the population, though this time because HIV hasn't been around for very long (really only one or two generations), and hasn't been widespread enough for strong selective pressure.

Why limit yourself to animals, though? We're fundamentally the same as single-celled organisms when it comes to mutations and evolution. The Lenski lab recently observed the generation of a new mutation that allowed a population of E. coli to metabolize citrate, which they were unable to use as an energy source before. ‘


Is sickle cell disease a beneficial mutation?

andymanec unequivocally stated that sickle cell is a beneficial mutation. Of course, there is no dispute that it confers some survival benefits in the face of falciparum malaria, a microbial parasite spread by biting mosquitos which can kill a previously healthy person in 48 hours and is still one of the biggest killer diseases worldwide. But how does the mutation confer benefit? By making screwed up haemoglobin which in turn leads to deformed red blood cells which are so dysfunctional that the malaria parasite can’t survive so well in them.
Sickle cell haemoglobin can arguably be called beneficial in this sense, but ONLY as it ameliorates a deadly disease. If malaria were removed from the equation, it would clearly be seen as 100% bad. The key thing is that it is what Professor Michael Behe refers to as a ‘blunted or broken gene’.
Similar theoretical examples in addition to the one cited above by the Darwin sceptic who posed the question could include

-a beautiful samurai sword that was more efficient as a potato peeler after being put in a vice and smashed with a sledgehammer until only 3 inches of the blade was left

-a young man who avoids being drafted into a suicidal and unjust war due to a broken leg or epilepsy.

-a woman whose risk of dying in childbirth is eliminated due to sterility 

I could go on but the point is made. Sickle cell disease is a ROTTEN example of a beneficial mutation. Look it up-it SUCKS! The fact that it is still used as an example of a beneficial mutation is a potent demonstration of the weakness of the evolutionists’ case. In Darwinian speculation, haemoglobin would have to have evolved slowly by numerous successive small changes from simpler beginnings, via a long string of molecules that were on their way to becoming fully functional haemoglobin as we know it. Sickle cell (and there are other examples of haemoglobin that is less efficient than normal due to one or more amino acids being out of place due to mutation see or here Its true that some small ‘sideways’ variations confer limited situational benefit, but evolution has to explain how the whole molecule evolved. It has at least to demonstrate by theoretical biochemistry a complete passage from zero to haemoglobin with every stage functioning at least well enough to allow survival and reproduction. Currently the best it can do is assert that some of the components of haemoglobin are present in some other processes. That vague clutching at straws will not do. The transition needs to be demonstrated, at least in a credible molecular computer simulation. You cannot get from A to Z in 'numerous small successive steps' if any one of the steps is non survivable, and natural selection will not take the process forward unless each stage is an improvement on its predecessor, Darwin was quite clear on this point.
What we see in the various mutated forms of haemoglobin (haemoglobinopathies, where the suffix ‘-pathy’ means disease) that are documented in the world medical literature is that once you get a step or two away from good haemoglobin, you get progressively worse haemoglobin until you get NO haemoglobin because the molecule is too deformed to function AT ALL and survival of the whole organism is not possible. Natural selection cannot select you if you are dead. Sickle cell haemoglobin is barely survivable, a bit more of the same random meddling and it would be lethal. This is really rather obvious, hence my cri de coeur at the top of this post-why do intelligent people fall for this stuff? to assert that this kind of process created the most potent piece of information in the known universe-our DNA-flies in the face of all reason.
All of this is highly supportive of Michael Behe’s idea of irreducible complexity (an irreducibly complex system fails COMPLETELY when essential parts are absent thereby precluding Darwinian gradualism) being an impassible barrier to Darwinian slow change 'Climbing Mount Improbable' style. The challenge which evolution cannot meet is to credibly set out in detail a series of gradual steps by which functional haemoglobin (worm, mouse, elephant or human) came into existence by a Darwinian process of gradual, successive small variations (caused by random mutation) from a ‘simple’ predecessor molecule that was not haemoglobin. It can't do this for any other biomolecular process either. The response ‘it must have happened gradually in deep evolutionary time’ is simple faith in a ‘Darwin of the gaps’.
I will return to andymanec’s other examples later, having other stuff to do this morning and wanting to keep posts reasonably short. Meanwhile there is a link on the blogroll to Behe on the Lenski e.coli story which I believe is another example of evolutionists making a mountain of 'evidence' from a molehill of information.
The role of DNA Mutations in supposed molecules to man evolution is not peripheral. We are what we are because of the coded information on DNA, which was either created by a Designer or else by blind forces. It does matter and we have to choose, based on the best evidence.



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