Mutation Rates: A bigger problem for YECists

[shernren]

I know, that's why I said it was not an exact example. (Perhaps gluadys can give a better one.) But I hope you see the problem we see in your position: that on the one hand mutations are not a sufficient source of evolution over extremely long time-scales, but on the other hand mutations are a sufficient source of diversification within kinds over extremely short time-scales (on the order of thousands of years or about hundreds of generations). Also, we are zooming in on the specific level of diversity at a single genetic locus, which cannot be explained from a single ancestral pair.

Mind you, the diversity across different branches of life is not all that big. From what I've read, 99% of human proteins have some analogs somewhere in the tree of life - only 1% are unique.

 

[rmwilliamsll]

bearing in mind that Adam & Eve, being created flawless

no. they were created tov-good, suitable, sufficient, complete. they obviously were not flawless because they screwed up. same line of thought that God created the universe perfect, no where is that claim made in Scripture. I don't think you can even show it to be Leibniz's "best of all possible worlds" but that is a discussion for another place.

what suffices here is to note that Adam/Eve were neither perfect nor flawless. And to reason from that position is going to lead nowhere interesting.

 

[gluadys]

Mutations do occur. What Darwinism needs is changes of the kind that allow us to transition from 'simple' single celled life to what we see today. Mutations that confer immunity to bacteria are not the kinds of changes that are needed to support Darwinism.

Why do you say this? What leads you to believe that these kind of changes are not sufficient to support evolution?

Changes in morphology are needed, changes that grant advantages in that respect.

Why do you consider the sort of mutations which confer resistance to toxins are incapable of creating morphological change? I am not speaking of the specific mutations here, but of the type of mutations: insertions, substitutions, deletions, etc.

What other kind of mutations would be necessary for morphological change? How do you know that morphological change has not been created by this sort of mutation?

A common one is the fruit fly with another set of wings. But all this mutation really does is replace existing code with something poorer (non functioning wings), and also causes the fruit fly to loose a morpohological trait that aids with in-flight balance.

Well, there you are. This is a morphological change due to a mutation. So your initial contention that mutations cannot produce morphological change is falsified by your own example. The fact that this particular change is not advantageous is irrelevant. Mutations in and of themselves cannot be called beneficial or harmful or neutral. That is for natural selection to determine. If mutations can produce a morphological change that is not advantageous or that is neutral, they can also produce a morphological change that is beneficial. The mechanism of mutation does not differ depending on the fitness of the outcome.

Mutations do not provide the raw stuff necessary.

Please show why this is the case. Why is mutation not a sufficient source of the variation needed for natural selection to act on?

Of course, that begs the question of why God would want humans to be lactose intolerence in their adult years, if he original designed it that way I don't have an answer to that.

Most mammals are lactose intolerant in their adult life. In nature most mature mammals do not drink milk. (Possibly lactose intolerance is also connected to weaning, but I am not sure of this.) Milk is intended to be a food for infants. There is no reason humans would not share the same features as other mammals, especially as hunter-gatherers. It is only when they began herding animals that using the milk of non-human animals as food became part of human culture. Not surprisingly, the ability to tolerate lactose in adults appears primarily among ethnic groups that practice(d) pastoralism.

 

[Mallon]

Well, there you are. This is a morphological change due to a mutation. So your initial contention that mutations cannot produce morphological change is falsified by your own example. The fact that this particular change is not advantageous is irrelevant.

In fact, to say that such a mutation could not be advantageous is false. Sure, here on the mainland, a fruitfly without wings would be at a loss. But when placed on a windy island, we know that natural selection tends to favour those insects bearing the wingless mutation as it prevents those insects from being blown out to sea when the wind picks up. The walking stick insect is a great example.
Lesson learned: "Advantageous" and "disadvantageous" are relative terms.

 

[gluadys]

(bearing in mind that Adam & Eve, being created flawless, would have had no recessive mutations to cause troubles with siblings having children).

This is a weird thing to say about recessive mutations (sic). Do you mean recessive alleles? Do you know why some alleles are called dominant and some recessive? What makes you think this has anything to do with the troubles of in-breeding?

Of course, for natural selection to take place, these two would need to have many children, who have many children, so that certain alleles become more frequent.

Natually, population growth will increase the absolute number of copies of each allele. But what we are looking for is not how many alleles there are, but what the proportion of one to another is. And whether that proportion is changing from one generation to another.

Population increase alone will not change the proportion of one allele to another. In fact, as Mendel showed, the proportion of one allele to another will remain constant unless factors beyond reproduction are also present. Natural selection is one of those factors.

But we don't know what the pre-flood population distribution was like. Perhaps racism was uncommon, and diversity was seen mixed together. Perhaps people did congregate with morphologically similar humans, and thus selection played a part. The point is that two parents (animal or otherwise) contain within them a great diversity to form many subgroups given enough generations.

But not enough to account for a diversity of alleles themselves unless given much more than 6,000 years.

 

[sfs]

Thanks for your response.

And thank you for yours. I appreciate non-hostile interactions. Hostility gives me a stomachache.

If I understand correctly, most cases of bacterial immunity is the result of a failure to create a certain enzyme, so the bacteria can no longer poisoned. This, while conferring an advantage, obviously is a loss of information. Much like a bank vault that is more secure because it has no doors - it provides a specific advantage, but through a loss (no longer possible to access the vault).

Some bacteria I believe do have changes that are directly beneficial though, and not the result of a mutation that causes a loss of information. Unfortuantely, I've only heard that such bacteria exist, and nothing more.

While there are cases of resistance that are as you describe above, there are quite a few different ways that bacteria develop resistance, and some of them clearly involve a gain, rather than a loss, in function, e.g. an improved ability to pump the antibiotic out of the cell, or an ability to attack the antibiotic itself chemically. (Look up beta-lactamase for examples -- that's the bacterial enzyme that attacks a key part of penicillin and related antibiotics.)

Mutations do occur. What Darwinism needs is changes of the kind that allow us to transition from 'simple' single celled life to what we see today. Mutations that confer immunity to bacteria are not the kinds of changes that are needed to support Darwinism. Changes in morphology are needed, changes that grant advantages in that respect. It's one thing to change details inside a building (knock out a wall to give new access to a room) - it's another thing entirely to describe the construction of a building from scratch.

There's no need to leap directly into the development of multicelled life: take small steps. Darwinism first needs to be able to explain the changes between closely related species, e.g. humans and chimpanzees. The great majority of the time, the differences between species are a matter of fairly small changes, not the development of major new body parts. Humans and chimps have all the same parts, after all, and the they all work in rather similar ways.

Do you see any fundamental problem with mutations causing that kind of change?

As someone who doesn't believe in Darwinism, I need to be able to see processes that are of the kind that would explain the origin of life today from a simple life form. Mutations do not provide the raw stuff necessary.

Where, in the web of life that we actually see, do you see the major breakpoints that evolution can't explain?

Based on your description, and some very quick reading (just got back from Church), lactose intolerence appears to be a mutation that prevents a shutdown in adults. ie, the destruction of a process that happens to lead to an advantage.

You could phrase it that way, or you could call it a gain of the ability to digest milk as an adult; the distinction is semantic. Biochemically, either direction is possible: there may be a signal that turns off milk production after weaning, and the human copy of lactase has lost the ability to respond to it, or human lactase may have gained the ability to respond to some kind of adult signal. What could prevent either one from happening? Regulatory regions around genes are just little bits of DNA sequence, after all -- no magic is involved. Mutations change one sequence to another all the time, and these are short sequences, so either change could happen.