The Randomized Death Barrier

I was having an interesting conversation with Russell Gold about evolution. Discussing evolution with Russ is always very interesting, and I tend to have a great time. I can heartily recommend it!

In that conversation I brought up the problem of the ‘Randomised Death Barrier'. Now, to be honest, I was not aware that anybody else had ever used that expression before, and was expecting him to ask me what on Earth I was talking about. But he ended up looking it up, which I found fascinating, and he came up with a definition which was at least in the right direction. But the definition had obviously been written by an evolutionist, and so it rather dramatically missed the point. Which gives me the opportunity of writing an entire post on the subject! (Indeed I have a good dozen ideas for posts just from this one conversation, including ‘What is Truth?’. Yeah Russ!)

The level on which it operates

So the first thing that we need to mention about the randomised death barrier, because it was the first thing and the most critical thing that the definition that Russ gave got wrong, is the level at which the randomised death barrier operates. So the randomised death barrier, as I envisioned it, begins with the existence of a single mutation. One little teeny mutation in one particular creature. We’ll make it a human just for the fun of it.

This mutation can occur in the germ cell of an adult, or it can even occur in a new child. I’m not an expert on these things, so I guess we’ll say that right as the egg and the sperm we’re doing their thing, some little X-ray came in and changed one little thing. But the point is that one little thing was changed. And this little thing that was changed, despite all the odds, is actually something that has the potential to become a positive mutation. There are no such things as truly positive mutations in the way that I’m meaning them here, but let’s pretend that this was one of those non-existent creatures.

So here we have this little positive mutation, and it has expressed itself either in a germ cell or in a human developing baby inside of his mother. If you abstract him at this point, then you can picture this particular child as one little floating atom among all the billions of other floating atoms in some great ocean. I suppose billions isn’t quite the right word. And we can say, “Okay, at what level will this particular atom float amongst all the other atoms?” And the answer, if viewed in this purely abstract way, is that this particular atom will float just a teeny bit higher than the average of all the other atoms. Because of, you know, the potential positive mutation.

Sperm

But unfortunately, for the theory of evolution, a human being is not an atom. It is a functioning, or in some cases not functioning, organism. So instead we start with the little germ cell inside of the father. And then if this germ cell is incredibly lucky, the father has an enchanted evening with some female. (Indeed, he’s not really a father yet, is he?)

So he has his enchanted evening with this particular female, and a gazillion or so sperm cells all shoot out of him and begin a great race for the great prize. And here we have the first application of the randomised death trap. Because just because this particular germ cell has some positive mutation does not mean it’s gonna win the race! Unless the particular positive mutation is race-winning (in which case the application is gonna be a circular), it has no more chance than any of the other germ cells of reaching the great goal, the wonderful prize. And most of the gazillion or so sperm cells are going to die. Cease to exist. Expire in place.

And this is the first and most dramatic application of the randomised death barrier. Even if you get the impossible mutation that is actually better than other mutations, the odds are incredibly high that it will die. Pass on. Or, perhaps, not pass on :)

Egg

Now let’s give the little bugger a little better chance. Let’s see to it that this positive mutation, this slightly better-than-the-others mutation, happens not within a male germ cell but within a female germ cell, otherwise known as an egg. Well, now it’s got a much better chance. If there is an enchanted evening at the right time, the egg is going to be fertilised by some lucky sperm. But let’s remember that the odds of the enchanted evening itself are not that great. I mean, even in a woman whose life is full of enchanted evenings, she can’t manage to have an enchanted evening more than once every 18 months or so. Which means it’s 17 out of 18 of all of her germ cells fail to prosper. They do not survive or thrive. They are flushed out with the trash.

Child

But now let’s get to the point of the randomised death barrier that most of us think of when we think about this concept. Namely, let’s say that the full organism actually exists. It’s living. It’s a little teeny growing child inside his mother. Well, here’s the deal. Like in the atoms floating in water, we have the idea that this little teeny child is going to do better than all of the other children because of this positive mutation. Now, first of all, that’s not the way most positive mutations work. But let’s say that this particular mutation is a good mutation and it will definitely help him in his life. You know what? That’s probably not gonna help much. Because most of the reasons for this child to live or die are exterior to any particular positive mutation.

This child might belong to a mother who is killed during a raid. Who is killed due to a famine. Who is killed due to a drought. Who is killed due to a plague. Who is killed due to angering her mother-in-law at the wrong time. Or by a jealous rival. I mean, who knows? Maybe the enchanted evening was not exactly according to Hoyle.

Birth

But let’s assume that the baby makes it out of the factory. That he is delivered with all his appropriate fingers and toes into the arms of his father. And then to the breast of his mother. For the overwhelming majority of children, for the overwhelming majority of their life, whether or not they’re going to manage to live is not going to depend on some little mutation. We’re not talking X-Men here where he has super strength or super speed. We’re talking about some slightly better system of sight or sound or smell or an endocrine system that operates just a little more efficiently than his fellows.

That is simply not gonna matter if there is a great war and everyone in its village is wiped out. If there was a famine in his area. If a plague comes through his area. If a friend of his gets mad at him and so he is suddenly killed.

The point of the randomised death barrier is that it operates before this positive mutation can prove itself in a population. Before it can get wider distribution.

Grandpa

In fact, we can’t even key off that word ‘wider’. Let’s say that the little nipper does survive and let’s say that he does thrive, and there he is in his little village, a happy grandfather of 29. All of them have managed to receive this wonderful mutation that he has. The randomised death barrier can still operate. That particular village can be wiped out. People from that village can be taken captive, and all of the males with the genetic line could be castrated and prevented from passing on the mutation to any other children. Fire, flood, all sorts of things can happen that will prevent this gene from being passed on, despite its being slightly advantageous or even very advantageous. Until we get to the X-Men or Superman or Green Lantern level this advantage will not stop this child from being killed in a sort of generic way.

Illustrated

I am notoriously bad at actually creating illustrations for my posts. But every time I wrote one of the above sections, I envisioned, in my head, an illustration for it. So I’ll try to pass those on:

The Randomised Death Barrier: Generic

Some Mutation → [Random events in the environment that can kill them despite their fitness] → Introduction into the larger gene pool

IE while we think of the fitness of the organism as being what allows them to thrive, or not, in the larger gene pool, it is actually the case that a large proportion of that survival is just a matter of accident.

The Randomised Death Barrier: Sperm

Some Mutation in a male germ cell → [The extreme unlikelihood of the enchanted evening + winning the race] → Introduction into the larger gene pool

The fact of a possibly positive mutation in one germ cell does not increase the male’s likelihood to ‘get some’ that evening, nor that the woman will be on the fertile part of her cycle, nor that that sperm will win the race to the egg.

The Randomised Death Barrier: Egg

Some Mutation in a female germ cell → [The unlikelihood that that particular egg will be fertilised and successfully implant/live to birth] → Introduction into the larger gene pool

The fact that an egg contains a potentially positive mutation does not increase the likelihood that that egg will drop for an enchanted evening, be fertilised, implant, and grow to be born. And that the mother won’t be killed sometime during gestation.

The Randomised Death Barrier: Baby

Some Mutation in an actual nursing infant → [The difficulty of any particular child of living through childhood, finding a mate, and successfully reproducing that particular mutation] → Introduction into the larger gene pool

Just because a child has a possibly positive mutation does not mean that they will live to pass on those genes. Even if the mutation does do positive things for them, unless they rise to the level of Spider-Man, they do not help them survive the larger environmental issues: their parent being killed when they are young, drought, famine, flood, war, fire, plague, etc.

The Randomised Death Barrier: Grandfather

Some Mutation in a female germ cell → [The difficulty of any particular small population group with a positive mutation of being able to introduce it into the larger population] → Introduction into the larger gene pool

Even if a potentially positive mutation gets successfully introduced in a small population, that mutation alone will not ensure it survives the larger environmental pressures: war, famine, drought, etc.

Error Correction

Now to take a step way back to the beginning, because there is something else that this positive mutation must survive: the error correction system. Because a mutation is an ‘error’, and the organism is designed to reject errors. So the very first thing that a new mutation has to survive is the organism itself.

But since this death barrier is not randomised, I can’t really include it.

Conclusion

This conversation is part of the general conversation about how difficult it is for evolution to make progress by way of random mutations. The problem begins with the fact that there are no positive mutations. Mutations are overwhelmingly negative, with a few neutral ones thrown in.

The problem continues with the fact, as I mentioned in my earlier post, that even potentially positive mutations all by themselves are almost never actually immediately helpful. They require a whole host of other mutations to make them useful.

The problem continues with the fact that unless a mutation is particularly successful, all that it’s gonna happen is it’s going to randomly drift through the population and be just as likely to be exterminated from the population as any other particular gene of that level. The way the math works, the introduction of a new gene into a population does not mean that that gene will continue through the population.

And as I hope I have made clear here that the progression of that gene to the population can also be stopped for reasons far beyond the ability of any particular mutation to prevent. Thus the randomised death barrier.

Source

Russ’s response on the Randomised Death Barrier:

The argument typically goes like this:

Evolution requires many small beneficial mutations to accumulate over generations.

But if an organism dies before acquiring all the necessary mutations, the evolutionary pathway is supposedly “blocked.”

Therefore, the organism can never evolve complex new features because random death prevents the required sequence of mutations from occurring.

The problem with this argument is that it misunderstands how evolution works.

Evolution does not require an individual organism to survive long enough to accumulate many mutations. Instead:

Mutations occur in different individuals across a population.

Beneficial mutations can be passed to offspring if those individuals reproduce.

Over many generations, natural selection increases the frequency of advantageous traits in the population.

In other words, evolution is a population-level process, not something that happens by one individual collecting mutations throughout its lifetime.

So there is no scientific principle known as a “randomized death barrier.” The phrase is generally used in creationist or intelligent design arguments to suggest that random mortality makes evolutionary change impossible, but evolutionary theory already accounts for the fact that many individuals die before reproducing. Natural selection operates precisely because some individuals leave more offspring than others, allowing advantageous genetic variants to spread over time.

The entire exchange, much of which from my part was ‘typed in’ via voice recognition on my phone while walking around WalMart, can be found in the comments on my post ‘The Big Three’.

Links

Some other posts on the subject.