• Quick note - the problem with Youtube videos not embedding on the forum appears to have been fixed, thanks to ZiprHead. If you do still see problems let me know.

Split from: I'm reading "The God Delusion" - a review in progress

Evolution is random. Given the general understanding of what random means among the population, it does provide a hurdle to arguing against those who misuse the word, intentionally or otherwise, in debates about origins.

Countering that the creationist has used a false premise, "evolution is random", in his argument would be misleading on our part, intentional or otherwise. The problem becomes how best to explain that randomness doesn't necessarily lead to chaos/disorder.

I've yet to see a 2 minute "intro to randomness" that doesn't involve the standard coin flips, or die rolls. As such, I've yet to come across a really good ,quick and easy to understand counter argument to the standard attack other than to mention that randomness in a process doesn't lead to the qualities they expect and that a full rebuttle would require more than a one liner, a lunch discussion or even a long evening discussion to get across.

Of course, that isn't so much a rebuttle, and will be viewed by some as evasion. But coming up with an honest, accurate and short rebuttle isn't simple given the subject.

Walter
 
Foster Zygote said:
I could swear that some months ago I posted a quote by Dawkins from The Blind Watchmaker in which he addresses the issue. It made it clear that Dawkins had no intention of denying that there is a random element involved in evolution. What he did want to address was the creationist claim that evolution is entirely random, the "tornado assembling a working 747" argument. Of course, T'ai probably didn't read it if he had me on ignore.
Click to expand...

I don't think T'ai has anyone on ignore. It's just that other people's clear explanations don't help him stir up controversy and get passed over.
 
Jekyll said:
Any of these: http://www.answers.com/random&r=67

Apart from number 2 in the American heritage definitions and the wiki entry.
Click to expand...
Yes, I see. From the first bit of that link:
ran·dom (răn'dəm) adj.
1. Having no specific pattern, purpose, or objective: random movements. See synonyms at chance.
2. Mathematics & Statistics. Of or relating to a type of circumstance or event that is described by a probability distribution.
3. Of or relating to an event in which all outcomes are equally likely, as in the testing of a blood sample for the presence of a substance.

idiom:

at random

1. Without a governing design, method, or purpose; unsystematically: chose a card at random from the deck.
Click to expand...
Obviously, 2 is (more or less) the technical definition we've been referring to here. The other definitions - especially the 'idiom' version - seem to fit in more with the strawman ID statement about evolution being 'random', e.g. the old candard about a 747 being assembled by a tornado in a junkyard.

Can we all agree now that evolution is indeed random, in the technical sense of the word (i.e. 2 above), though not in the 'layman's sense' (i.e. the other definitions above)?
 
Here's another thing that's been bugging me:
Foster Zygote said:
...
If a series of coins are tossed that have a 50/50 chance of coming up heads or tails, but only those that come up heads are selected to be placed in a piggy bank and the coins that come up tails are thrown into a river, then the results of the selection process are not random.
Click to expand...
This idea has been stated in several forms in this thread, i.e. that while the mutation process is certainly random, the process of natural selection by which less-well-adapted variants are culled from the population is deterministic.

This seems to me to be a highly dubious claim. I'm having trouble seeing how the natural selection process could be completely deterministic. Certainly, the more-well-adapted variants will have a higher chance of surviving and reproducing. Perhaps siginificantly higher. Likewise, a poorly-adapted variant will have a much higher chance of becoming lunch. But it's not a certitude. These probabilities are not 1 and 0.

To put it another way, suppose we know the set of gene/allele frequencies of a population in a given generation. Even if we suppose that no mutation events will occur between this generation and the next, we cannot in advance specify the precise gene/allele content of the next generation. There is still significant randomness left over. Who will be eaten, who will reproduce, how much will they reproduce, etc. Now of course this is a sort of 'directed randomness', in the sense that the more adapted variants have a much better chance. But this does not suddenly make it nonrandom.
 
Vorticity said:
Can we all agree now that evolution is indeed random, in the technical sense of the word (i.e. 2 above), though not in the 'layman's sense' (i.e. the other definitions above)?
Click to expand...
Not I.
ran·dom (răn'dəm) adj.
1. Having no specific pattern, purpose, or objective: random movements. See synonyms at chance.
2. Mathematics & Statistics. Of or relating to a type of circumstance or event that is described by a probability distribution.
3. Of or relating to an event in which all outcomes are equally likely, as in the testing of a blood sample for the presence of a substance.

idiom:

at random

1. Without a governing design, method, or purpose; unsystematically: chose a card at random from the deck.
Click to expand...
What is the specific pattern of evolution? What is the purpose? The objective?

What is the governing design? Method? or Purpose?

Given definition 3 I would agree evolution isn't random, but then under that definition the sum of rolling two six-sided dice (2d6 in geek speak) isn't random either. (Aside, the example they give for definition 3 isn't an example of a situation "where all outcomes are equally likely either).

One might argue that the "governing method" of evolution is not replicating some genes in the next generation, but given the non-deterministic nature of that, it is still a weak argument to say evolution isn't random.

Walt
 
Vorticity said:
Here's another thing that's been bugging me:

This idea has been stated in several forms in this thread, i.e. that while the mutation process is certainly random, the process of natural selection by which less-well-adapted variants are culled from the population is deterministic.

This seems to me to be a highly dubious claim. I'm having trouble seeing how the natural selection process could be completely deterministic. Certainly, the more-well-adapted variants will have a higher chance of surviving and reproducing. Perhaps siginificantly higher. Likewise, a poorly-adapted variant will have a much higher chance of becoming lunch. But it's not a certitude. These probabilities are not 1 and 0.

To put it another way, suppose we know the set of gene/allele frequencies of a population in a given generation. Even if we suppose that no mutation events will occur between this generation and the next, we cannot in advance specify the precise gene/allele content of the next generation. There is still significant randomness left over. Who will be eaten, who will reproduce, how much will they reproduce, etc. Now of course this is a sort of 'directed randomness', in the sense that the more adapted variants have a much better chance. But this does not suddenly make it nonrandom.
Click to expand...

Who said that natural selection is deterministic?

It is "deterministic", as in "whatever works", but there's no higher goal apart from that. A better term could be utilitarian.
 
CFLarsen said:
Who said that natural selection is deterministic?
Click to expand...
Well, look at Foster Zygote's metaphor:
Foster Zygote said:
If a series of coins are tossed that have a 50/50 chance of coming up heads or tails, but only those that come up heads are selected to be placed in a piggy bank and the coins that come up tails are thrown into a river, then the results of the selection process are not random.
Click to expand...
Here the selection process (i.e. "head -> piggy bank, tails -> river") is entirely deterministic. If we know whether it's heads/tails, we know where it's going.

I suspect that a much better analogy for evolution would be something like: "If it comes up heads, it has a %55 chance of going into the piggy bank, but if it comes up tails, it has only a %45 chance."
It is "deterministic", as in "whatever works", but there's no higher goal apart from that. A better term could be utilitarian.
Click to expand...
I'm not sure I follow you. In this context, "deterministic" would mean that given a particular specification of the gene/allele frequencies in a population, we can state exactly which individuals will be culled by natural selection, and which will not be. I'm saying this is almost certainly false: The culling has a random component as well.
 
Yes, but we can only do it once, because the species would have evolved into something different. Not a lot of difference, but different nonetheless.
 
ImaginalDisc said:
Argh! Fitness is a measured quality of the number of descendants an organism has. Replacing "fittest" with its definition in "survival of the fittest" results in a tautology.
Click to expand...
You forgot to replace the word survival with 'The number of descendants an organism has' :p . Unless you're talking about the survival of genes in which case it isn't a tautology.
 
ImaginalDisc said:
Argh! Fitness is a measured quality of the number of descendants an organism has. Replacing "fittest" with its definition in "survival of the fittest" results in a tautology.
Click to expand...

Tautologies are not always bad. We see the things we see around us today because the ones that didn't produce decendants don't have any decendants for us to see. This is the founding principle behind theories of evolution. It is a tautology, but one that many people either don't see or refuse to believe. Pointing it out is not a debating fallacy, it is simply stating a fundamental truth that is absolutely vital for any understanding of how evolution works.

Walter Wayne said:
What is the governing design? Method? or Purpose?
Click to expand...

Are you claiming that natural selection is not the governing method of evolution?
 
Vorticity said:
Actually, you did:
Click to expand...

I pointed out that "deterministic" isn't (necessarily) the opposite of "random".

You can say it is "deterministic" for each generation. The next generation is not solely dependent on the preceding.
 
CFLarsen said:
I pointed out that "deterministic" isn't (necessarily) the opposite of "random".
Click to expand...

In this context, "deterministic" is certainly the opposite of "random".

The relevant definitions from http://dictionary.reference.com/browse/deterministic are:

deterministic

adjective
an inevitable consequence of antecedent sufficient causes

WordNet® 3.0, © 2006 by Princeton University.

deterministic
1. Describes a system whose time evolution can be predicted exactly.
Contrast probabilistic.

The Free On-line Dictionary of Computing, © 1993-2007 Denis Howe
Click to expand...

(The other definitions, relating to the philosophical notion of "determinism", are not relevant to the current, largely mathematical, discussion.)

CFLarsen said:
You can say it is "deterministic" for each generation. The next generation is not solely dependent on the preceding.
Click to expand...

If, by your second sentence here, you mean that the next generation may depend on a sequence of preceding generations, then you may or may not be correct. The process of evolution would still be random (not deterministic), however. The technical term for this type of stochastic process would be "non-Markovian".

If that isn't what you meant, then your statement is a non-sequitor: The two sentences in the above quote seem to contradict one another.
 
You must log in or register to reply here.

Back
Top Bottom