Genetics and Poor Math the Argument...

[farmerjay86]

Hello Fellow Forum Members,

 

First off I would like to thank everyone that commented on my last post, they were very helpful and educational. Since then I have done quite a bit of research on genetics and the mathematical equations involved, it's been very enlightening and I thoroughly respect anyone who works in this field of science.

 

Anyway back to the crazy creationist arguments....

 

As I mentioned in my previous post my father is a Jehovah's Witness who rejects evolution and believes that the earth is only 6,000-10,000 years old. He also believes that the science of genetics as it relates to evolution and mutations is false and that he can prove it. Bellow is the first part of his mathematical "proof," I had assumed he was going to use an equation a little more complex than he did. His first "proof" is a simple compounding probability argument and in my first response I pointed out that this is not how genetic material accumulates and sent him links to the equations for replicator equations http://en.wikipedia.org/wiki/Replicator_equation and Markov Chains http://en.wikipedia.org/wiki/Transition_probabilities. I think these are the equations used for this sort of thing but I would like some feedback. I also pointed out a few other factual errors to him, such as the genome size of cyanobacteria today is most likely larger than it was 3 billion years ago and has probably changed and that genome size doesn't correlate to larger or more complex physiology and thus wouldn't absolutely need more resource.

 

Well anyway here is the first part of his argument, I would appreciate any input and more insight.

Thanks,

FarmerJay

 

 

 

This is the first math salvo of what I expect to be a lengthy correspondence, especially when you pull in help.

First Salvo:

We agreed the first viable organism started with 3 base pairs of genes.

We also agreed that according to the fossil record, the second organism to evolve was the cyanobacteria which have 2488635 base pairs of genes.

So, we need to "evolve" 2488632 base pairs of genes.

We agreed that the working ratio of good to neutral\bad mutations for the prokaryote is 0.00041. In other words only 0.00041 in one mutations are good. That’s a very low number.

Here’s the argument:

I know your assumption is that there are billions of these duplicate simple 3 base pair pre-oxygen critters, happily bubbling away mutations in the mud at the bottom of the dead sterile oceans all at the same time; so 41­^-4 (.00041) doesn’t seem unrealistic.

So far, I agree the above isn’t impossible; however the mathematical problem for evolution comes when you want a series of related mutations.

Some problems immediately pop into mind:

· As soon as one critter makes the next required mutation step – it is no longer billions – it is one. All of a sudden all those other “biiiillions” become competitors to the “one” that has mutated and the odds drop off a cliff.

· This “one” has to survive long enough to either reproduce its billions or pull off the next step itself within its very short lifetime.

· You assume the next good mutation is not only beneficial, but it coordinates\matches with the rest of the organism’s original physiology AND helps it survive.

· Mutations that move the critter to a more complex physiology most often would mean more genetic mater – also know as larger size. The larger it is the greater need for food. It needs to mutate methods of movement appropriate to its size, etc., all this would logically make it less advantageous while it goes through these stages.

We know the odds of a good mutation in the target critter is 41­^-4.

The odds of the “one” critters offspring\lineage (assuming it survived long enough to reproduce, see above) of a good mutation in the target critter is 41­^-4 also.

The odds of getting two mutations that are related to one another is the product of the separate probabilities:

The second mutation would be 41^-­⁴ X 41^-­⁴, or 41^-8.

That’s 0.000000041, (billion)

Any two mutations might produce no more than a fly with a wavy edge on a bent wing.

That’s a long way from producing a truly new structure, and certainly a long way from changing a fly into some new kind of organism. You need more mutations for that.

So Jay, what are the odds of getting three mutations in a row?

The next mutation would be 41^-8 X 41­^-8, or 41^-16.

16 zero, 0.00000000000000041.

No way just 4 mutations will create new genetic material (new base pair) - so the fourth woul;d be 41^-32

It hurts my head to try to figure out how large of a number that is. I don’t even know what it would be called; one hundred trillion trillions maybe?

Suddenly, the ocean isn’t big enough to hold enough critters to make it likely for you to find a pre-cyanobacteria with three simultaneous or sequential related mutations.

What about trying for five related mutations? 41^-64. Suddenly, the earth isn’t big enough to hold enough organisms to make that very likely.

And we’re talking about only four mutations.

It would take many more than that to change a your 3 pair critter into a photosynthesizing machine with 2488632 base pairs of genes capable of creating the earth’s oxygen ozone layer – critical for all other life to form there after!

- four mutations don’t even make a start toward any real evolution.

And remember – you only have 200,000,000 years to pull off:

0.0000000000000000000000000000000000000000000000000000000041……

Go For It !!!!

Your reply?

[CharonY]

I am sorry, but as already mentioned, the assumption that the first organisms had three base pairs is pretty much flawed and any argument starting from this assumption is not going to go anywhere.

[Arete]

There's already a considerable number of issues with the argument, including but not restricted to:

 

a) As CharonY points out, the first organism is extremely unlikely to have only had 3 base pairs of DNA.http://www.biog1105-1106.org/demos/106/unit04/3b.rnaworld.html

b) Mutation rates vary in both time and across organisms, so you can't logically apply a uniform mutation rate. http://www.nature.com/nrg/journal/v8/n8/abs/nrg2158.html

c) The calculations ignore large scale mutations such as recombination and gene duplication events.http://en.wikipedia.org/wiki/Mutation#Classification_of_mutation_types

d) More complex eukaryotes don 'tnecessarily have larger genomes that less complex eukaryotes.http://en.wikipedia.org/wiki/File:Genome_Sizes.png

[farmerjay86]

Thank you for helping. I pointed out some of those flaws. Particularly the problem with a uniform mutation rate and he gave up.

[overtone]

More basic objections:

 

There was no such thing as a "first organism".

 

The immediate precursors to cellular replication did not necessarily have any DNA whatsoever, let alone "base pairs of genes" - whatever that was supposed to mean.

 

Multiplication of event probabilities to get conjoined event probability assumes independence of events - an invalid assumption here.

[Ringer]

Hell, if you he wants to make up what are basically non-sense assumptions put in the assumption that the rate of autopolyploidy is 3*10^-5 and gene dosage had little effect on viability. You'll get to your number in no time (from an evolutionary perspective).