MrSparkle

I've foten heard the creationist argument that you can't randomly create a human being. It's true, millions of letters of genetic code and unimaginable complexity go into each one of us, that can't be randomly created, it takes billions of years of evolution to do that.

1000 monkies on 1000 typewritters couldn't in a billion years write a Shakespear play. Theres no chance.

But, thats not how evolution works, evolution works by constantly improving what it already has, benifical mutations take hold in a population as the "less" evolved die off.

I found this to be a hard concept to illisrate even to myself, until this semester. My evolution professor made a little excel spread sheet to "evolve" a phrase. I have borrowed his original idea, put it in C++, and added a little more functionality to it.

http://www.runuo.com/zippy/evolve.zip
( source code: http://www.runuo.com/zippy/evolve_source.zip )

This program takes a phrase you give it (for exmaple, a line from Shakespear, "what a piece of work is a man!"), an alphabet (in our case, 26 letters + space and !), and attempts to "evolve" a random string of characters to this phrase using random mutations. With the default settings it takes about 800 generations... play around with it, I find it very illuminating.

I hope at least someone finds this interesting, it deffinently helped paint me a picture of how you can get from a single cell to a human (or an ape, bird, cat, dog whatever).

For the genticially inclided, give it an alpha bet of ATGC, and a target genome, see what happens :-)

Mageth

1000 monkies on 1000 typewritters couldn't in a billion years write a Shakespear play. Theres no chance.

Actually, the argument usually goes that there is a chance that the monkeys would produce a Shakespeare play (though the monkeys would have no idea that they had). Given enough time and enough monkeys, they would produce a Shakespeare play; eventually, Shakespeare's entire works.

But you're correct; that's not how evolution works.

Gooch's dad

Yeah, now you understand the concept, I understand the concept, but creationists shove their heads...um...in the sand and refuse to understand it.

What they'll counter with is, "you've set a goal for your program of trying to match a Shakespeare phrase, and you're an intelligent agent, so all you've done is prove that evolution requires an intelligent agent".

Of course they're completely missing the idea of how natural selection works as a filter.

Shadowy Man

Maybe I'm missing something, but why is that not a fair counter? You have predetermined the phrase, and then thrown out any bits that didn't correspond to your end product.

I do understand the basic concept of evolution through natural selection, but I think this type of example is a very bad one.

Gooch's dad

Well, it is a fair counter, in that an intelligent agent IS involved in the program example.

But the purpose of the program is to demonstrate how a selection process, acting on each generation, is a completely different process than a purely random event generator.

This is the same sort of program that Dawkins described in his book "The Blind Watchmaker", and he is quite clear about the stated goals--it isn't a 'model of evolution', it is simply demonstrating the non-random effect of reproductive (or repeating) selection.

Thanks for keeping me honest

-Kelly

Shadowy Man

This is true, but it shouldn't be used against God types because of the intrinsic need for a predefined goal. Although the example may support your argument well, it actually supports their argument better.

There must be a better example.

One that I've thought of is if you take a big jar and put in rocks of varying sizes, some big some small, close the lid and then shake vigorously for a long time, the rocks will actually adjust themselves in the jar according to size. In that sense you get order out of chaos with no specified goal in mind and there's nothing intrinsic to shaking the jar that would lead you to expect that the rocks should segregate. Then you can try to calculate the odds of getting that particular arrangement of rocks by random.
How's that?

Gooch's dad

Well, there are plenty of examples, such as bacteria evolving resistance to antibiotics, or the nylon-eating bacteria which evolved 'in the wild', but creationists call such cases 'adaptation rather than evolution'.

Funny, though, they usually can't give a good definition of what the difference is between adaptation and evolution.

To have a really good example, you'd have to show that there really was no intelligent agent involved, and since the presupposition of the creationist is that there always is an intelligent agent involved, then we end up talking past each other.

Gooch's dad

Hey, you cheated and did a quick edit of your post! lol!!

That's a damned good example of order coming from chaos, without any specified goal. I like it!

:notworthy

MrSparkle

The problem with rocks is, they aren't demonstrating heritable variation.... It's true the program has a predetermained end, you just have to adjust yout hinking a little to go with the example.

Think of it like this, each word is an animal... you start out with a weird little creature, and it has 10 offspring, each offspring an exact copy of the parent except for a few mutations. Now, in order to choose the parent of the next generation, we decide which one is the "fittest" of the 10 we have. The way the program does this is comparing it to the phrase you entered in the begining. If this was nature it would be by seeing which one lived to sexual maturity and was healthy enough to produce 10 offspring.

So, we're mutating offspring and passing along heritable variations. The fittest of these offspring passes them on to new offspring, and eventually you get the phrase you put in in.

I can't think of a much better way of expressing the point, which (to recap) is that evolution is NOT saying we take a random bunch of dna until we get a human. What it IS saying is we start with something arbitrary and weed out what can't survive.

This example also illisrates some other points, like once you get to above 0.90 fitness, you see that a majority of the mutations are bad. You might also notice that if you increase or decrease the mutation rate very much, you may never reach your goal, because a mutation is evolved out of the population as soon as it comes in, and as a result of this, most of your offspring are LESS fit.

Doubting Didymus

There is NOTHING wrong with the predefined phrase example. I really don't understand what your problem with it is, shadowyman. The intelligent agent thing is NOT a valid objection at all. Not in the set up, or the end result. The start conditions (replication and variability) are already seen in nature, and the specified goal is simply an example of a selection pressure, where in nature the pressure is for increased replicability. It's true that creationists constantly fail to get this, but that's a problem with them, and not the analogy.