What evidence is there for evolution being non-random?

ImaginalDisc said:
I wouldn't. An airplane is not a living thing which reproduces and passes on heritable traits to its offspring.
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Nice dodge.

Just like the original argument.

Therein lies the problem with this whole issue. Saying any variation of "Evolution isn't random" or "natural selection isn't random" or any counterargument that tries to insist that "randomness" is part of the prolem misses the point. It's a lousy counterargument to an issue easily countered.
 
Meadmaker said:
Nice dodge.
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It's not a dodge, it's the best response to a dumb question. Evolutionary biology is the study of living things which grow, compete for resources, reproduce, and pass on heritable traits. Any comparison between living, reproducing things with heritable traits and non-living, non-reproducing things that have no heritable traits is completely invalid when discussing evolution. In the discussion of evolution, you cannot ask "How is a raven like a writing desk?" You can ask, "How is a raven like a flea?"
 
Non-deterministic: mutation.
Deterministic: selection.

The word random invokes imprecise and fuzzy notions.

Oh and don't look at one goddamn airplane if you want an analogy - look at the history of the design of airplanes. You will see a clear pathway of iterative design.

Airplanes did not spring off the drawing board fully formed any more than a hurricane could construct one.
 
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Yes, there's a good analogy!

Comparsions between Lilienthal's glider, Samuel P. Langley's Aerodrome, Wright´s Flyer, Santos-Dumont 14 bis and Demoiselle are very instructive. Now compare them with later models and the shift from biplanes to monoplanes. Evolution of WWII fighters is also a lesson!
 
Read something by an Evolutionary biologist . Richard Dawkins is very good at explaining something of this complex subject .
If evolution was random then anything could happen but in fact only stuff that allows survival can happen and good stuff is more likely to be passed on than bad stuff , hence non-random .
 
articulett said:
I got that definition from a physicist on a physics forum--see above.

Ya' think you might be the only one who thinks there is one true definition for the word random amongst scientists? I do.
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Schneibester's, Mijo's and Meadmakers definitions of random is the same as mine, and not "just a few statisticians and physicists" but most biologists, ecologists, chemists, indeed almost anyone who actually has to analyse random, or pseudorandom behaviour.

If identical starting conditions always give identical outcomes then it is nonrandom, if not it is random. In principle it can be desribed by a probability distribution.

ETA:

It's useless unless you actually USE the probabilities. Your saying evolution is random is like telling a client, your odds of having a child with Down Syndrome are random. It's meaningless.
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I would say that Downs Syndrome is possibly only pseudorandom, i.e. deterministic, howevcer with insufficient knowledge one can describe the chances or odds of it occuring within certain populations.

Because most organisms fail to successfully reproduce viable offspring, even otherwise "fitter" organisms are still quite likely to fail to reproduce. The "fitter" ones just have slightly better odds.

Certain features are likely to evolve many times (the eye, flight, large herbivores and their predators in grassland). Others are far rarer: (technological, social bipeds with language).

Why do I say this is rarer? Because if it was very likely, then they would have evolved before, as the 180 Million years of dinosaurs could have been plenty of time for this to evolve (maybe they did, and the KT impact was actually the result of an interplanetery war)... ;-)

Because the evolution of something like humanity is fairly rare, it then follows that a chance event on the way could have delayed this evolution significantly. The Toba eruption almost wiped humanity out. This was a "random, or pseudorandom" event.


Saying evolution is nonrandom is an innacuracy, which will do nothing to convinde cretinists, might confuse wavering IDists (who could see the hand of god as the guiding "supernatural selection") and confuse others. Saying it is "not disordered" does none of this.
 
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jimbob said:
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If identical starting conditions always give identical outcomes then it is nonrandom, if not it is random. In principle it can be desribed by a probability distribution.
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That's the problem though: identical starting conditions are impossible and very few (any?) real world processes give the same output twice. Therefore with the binary choice you stated above, (almost) everything ends up being classed as random, which is not very useful.

Most people I know appear to have the concept of a sliding scale of randomness. They use the word "random" to indicate they could not usefully predict what is (or was) going to happen next.

I think it's important to realise that at some levels of detail, randomness is not important to the analysis or understanding of what is going on, while at others it is essential. Many systems are modelled as deterministic with a random component added to them.
 
Correa Neto said:
Yes, there's a good analogy!

Comparsions between Lilienthal's glider, Samuel P. Langley's Aerodrome, Wright´s Flyer, Santos-Dumont 14 bis and Demoiselle are very instructive. Now compare them with later models and the shift from biplanes to monoplanes. Evolution of WWII fighters is also a lesson!
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WWII fighters did not evolve, they were developed over many iterations. All changes to the design were made deliberately in the light of experience.

One could now develop aircraft with evolutionary algorithms and test them in simulators.

Talking about "the evolution of the fighter aircraft" is just going to muddy the waters with IDists, who could then claim that evolution is synonomous with design.

homer said:
If evolution was random then anything could happen but in fact only stuff that allows survival can happen and good stuff is more likely to be passed on than bad stuff , hence non-random .
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It is all about probabilities (or odds if you prefer).

"Random" does not mean that anything could happen. Anything within the probability distribution could happen, but the odds may bd vastly different. (What are the odds of throwing a seven with a standard six-sided die?) What about throwing seven with a pair of dice, now what about throwing 12?
 
Most people I know appear to have the concept of a sliding scale of randomness. They use the word "random" to indicate they could not usefully predict what is (or was) going to happen next.

I think it's important to realise that at some levels of detail, randomness is not important to the analysis or understanding of what is going on, while at others it is essential. Many systems are modelled as deterministic with a random component added to them.
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I am talking over geological timescales, when it is almost completely unpredictible and random, not just due to a lack of knowledge/analysis.
 
jimbob said:
I am talking over geological timescales, when it is almost completely unpredictible and random, not just due to a lack of knowledge/analysis.
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I shall not derail the thread, but will add that after reading up on the possible interpretations of quantum mechanics, the lack of knowledge / unavailable knowledge points of view are alive and well. My determinism is safe (for the time being):)

However, I agree with you. For all intents and purposes, over long enough timescales natural selection is random.

That would be the final part to my explanation to someone wanting to understand the basics of evolution.

The first part would hold the selection function steady while I explained about random mutations being selectively culled.

Just a thought: Physicists are usually quite bright. Are there any who do not have a grasp on the basics of biological evolution?
 
jimbob said:
WWII fighters did not evolve, they were developed over many iterations. All changes to the design were made deliberately in the light of experience.


Well, evolution also requires iterations (mutation-selection "cycles"). The analogy was conceived in order to counter the "747 assembled in a hurricane" nonsense, misconception, fallacy, etc.

But you are right, since design changes in living beings (mutations) are random, while in airplanes, the product of ideas.

jimbob said:
One could now develop aircraft with evolutionary algorithms and test them in simulators.
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Yes, but note this peculiar fact:
If you set the algorithm to "evolve" say, high-altitude slow aircraft with great autonomy, the final product probably will be a light airplane with large wingspan and engines adjusted to work for a long time with small fuel comsumption and a relatively small rotation regime. In this sense, the result is "predictable", and the IDer could say its not a random proccess. Alternatively, he/she could claim the Intelligent Designer set the rules and the goals...

jimbob said:
Talking about "the evolution of the fighter aircraft" is just going to muddy the waters with IDists, who could then claim that evolution is synonomous with design.
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No doubt or disagreement about that.

Ultimately, all reasonings and analogies presented to IDers may be doomed to fail, for they will grasp at quote cherry-picking, evasions, distortions and semantic games.
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ImaginalDisc said:
It's not a dodge, it's the best response to a dumb question.
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So, when someone says assembling DNA by random chance is like building a 747 using a tornado in a junkyard, there are lots of options.

1. You can say, "That's stupid" or many, many variations on that theme.

That response is tempting, and sometimes appropriate, but it will never achieve any understanding, either of the person to whom you are talking, or any listeners. Somebody has told them that the analogy is a good one. You can try to convince them they are wrong, or you can call them idiots.

2. You can say, "It wasn't built by random chance. It was built by selection combined with random chance."

That response suffers from the objections I raised earlier.

3. You can say, "It wasn't built in a single step. It was built in multiple steps. Of course, each step was random, but there were literally billions of steps."

You still have to argue about whether there was enough time, and whether each step was stable enough to last to produce the next step, but I think you are better off.
 
Ivor the Engineer said:
I shall not derail the thread, but will add that after reading up on the possible interpretations of quantum mechanics, the lack of knowledge / unavailable knowledge points of view are alive and well. My determinism is safe (for the time being):)

However, I agree with you. For all intents and purposes, over long enough timescales natural selection is random.

That would be the final part to my explanation to someone wanting to understand the basics of evolution.
The first part would hold the selection function steady while I explained about random mutations being selectively culled.

Just a thought: Physicists are usually quite bright. Are there any who do not have a grasp on the basics of biological evolution?
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I was wondering that... physics, unlike computing and biology deals with replicators--information collected, stored and copied through time... chemists have synergy, but not exponential or algorhythmic replication and growth of a data.

They seem to think that there is a singular unambiguous definition of random, but I can't find it. But I can't even tell if they agree with each other much less the meaning or information passed on by saying, "evolution is random". It's unpredictable, unguided, but wholly dependent upon what has come before. Like you, I know many scientists. And the random parts of evolution are easy to explain. If you toss a coin enough times you'll eventually get 25 heads in a row, etc. Patterns from randomness aren't hard to convey...but replication...the sticking factor...incremental change coupled with exponential growth via replication--trillions of experiments going on every moment to be acted upon by the environment. I can't tell if they can't "get" it... Maybe they truly cannot understand how selection is different from the pool of randomness it selects from and why we differentiate--and how these organisms are replicators that beget not just one copy of themselves--but sometimes billions. Physics deals with the material world--but not "information" and not "replication". I wonder if you would see a difference in understanding amongst younger people who are used to computers that for many intents and purposes evolve and become more complex--(store, copy, and alter data) through time. What works is built upon. There's artifacts--the qwerty keyboard...and lots of randomness--but the stuff that "works" the best for the most is the stuff that stays and is built upon.

Earlier, I used the example of the internet...it wouldn't convey much information to say it evolved randomly. Many random components were involved. But, it was more like life--in that complexity multiplied itself and became more complex...no design--just design from the bottom up by everyone who uses it. It didn't work for mijo or MM or Schneibster or Jimbob. But my students get this analogy. It conveys information they can apply to evolution. But I'm not sure how calling evolution as a whole (random) adds anything to the equation. From now on I'm going to avoid the use of random or non-random when talking to a physicist, though.

I can see many different ways evolution itself can be thought of as random--but I can also understand why most people who understand it, go out of their way to distinguish the relative randomness of mutation (recombination, insertion, transpositron, etc) from the environmental forces that cull from it and decides who gets a chance and begetting the most copies of themselves.
 
jimbob said:
No, it develops
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It evolves.

And you do not have the same definition.

Moreover, selection is deterministic--what is selected depends entirely on what survives and reproduces successfully.

And saying all scientists agree isn't the same as it being true. I think you have a pretty strong sampling here of people who are saying the word is ambiguous even in scientific circles--and the internet agrees. Sorry. You're incorrect. And calling stuff random just because they are not deterministic via your definition of deterministic is not helpful in furthering understanding.

Whether selection is deterministic or "random" or "non-random" is a semantics game. The important part to convey is that preferential survival/reproduction means everything in the evolution--it drives it. Until you have a definition that incorporates that, you've just got yourself stamping in a corner saying, "Dawkins is wrong, wrong, wrong..." Evolution is a fact. The ways for best understanding it and explaining it will EVOLVE. Not randomly--but by what works, what creationist strawmen evolve, who the audience is, what scientists around the world find most useful conveying information and learning more. Your definitions are terribly obsolete.

And you haven't even been following the thread whereby I give example after example of creationist using the "science says this all happened by random chance" to create doubt in the minds of the public so that ID looks like a better answer. BTW, you fail in genetic counseling as well as communication of scientific concepts and idea.

And yes, all biologists no, that but for a hiccup of some ancestor during sex, you or I might never be--we understand the chance aspects. Do you have a clue as to the selection aspects? The way information is culled, stored, replicated, and changed over time to allow for the variety of life we see today. Do you have a clue why calling all that random leaves something out of the equation--namely incremental (but exponential) complexity over time--the stuff that works--sticks around to be refined and honed. That's a tad different than the randomness that makes galaxies a swirling pattern, don't ya' think?

Facts are the same for everyone. Defintions aren't. Even if you insist they are.
 
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Meadmaker said:
So, when someone says assembling DNA by random chance is like building a 747 using a tornado in a junkyard, there are lots of options.

1. You can say, "That's stupid" or many, many variations on that theme.

That response is tempting, and sometimes appropriate, but it will never achieve any understanding, either of the person to whom you are talking, or any listeners. Somebody has told them that the analogy is a good one. You can try to convince them they are wrong, or you can call them idiots.

2. You can say, "It wasn't built by random chance. It was built by selection combined with random chance."

That response suffers from the objections I raised earlier.

3. You can say, "It wasn't built in a single step. It was built in multiple steps. Of course, each step was random, but there were literally billions of steps."

You still have to argue about whether there was enough time, and whether each step was stable enough to last to produce the next step, but I think you are better off.
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Or you could reply like they did in the multiple links I gave you to scientists answering that very question. (!). You make up the answers and then tell us why they're wrong. Why make up the answers. They're all over the web. I've cut and pasted quite a few even. Talk Origins answers that question multiple times. Duh.
 
Correa Neto said:
No doubt or disagreement about that.

Ultimately, all reasonings and analogies presented to IDers may be doomed to fail, for they will grasp at quote cherry-picking, evasions, distortions and semantic games.
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Yes...and that is exactly why Dawkins says, mutations are random, while selection is not. (See quote on prior page--also it's in the answer to the silly airplane question that creationists use to try and make evolution sound "impossible"...natural selection makes you wonder what took so long--)
 
homer said:
Read something by an Evolutionary biologist . Richard Dawkins is very good at explaining something of this complex subject .
If evolution was random then anything could happen but in fact only stuff that allows survival can happen and good stuff is more likely to be passed on than bad stuff , hence non-random .
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Uh...you obviously haven't been reading the thread. There are plenty of constrained, time-dependent process based on non-uniformly distributed probabilities that all lead to orderly results. The problem with Dawkins and his intellectual compatriots (e.g., aritculett, Imaginal Disk, Ivor the Engineer, etc.) is that they use a very specific definition of "random" which is not universally recognized in any academic field, especially biology, as being the "correct" definition. This allows them ignore the fact that when people describe evolution as a "stochastic process" they are using a completely rigorous definition based in the principles of probability theory that allows for constraint, time-dependence, and non-uniformly distributed probabilities. It is also interesting that no matter how many times they are told that those who are arguing that evolution is better described as "random" n so far as "random" means "[o]f or relating to to a type of circumstance or event that is described by a probability distribution", they still come up with posts like this:

articulett said:
Oh mijo--a math problem with random variables is not the same as a "random math problem"-- But it's fine. I understand. You mean "described by or relating to a probability distribution" no matter which word you are using.
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articulett is clearly using "random" is the sense in which I have been exclusively using it in the first instance (red) and in a clearly more colloquial sense (e.g., the second, fifth and sixth definitions at the Online Dictionary of Online Computing or any of the definitions in the Urban Dictionary) in the second instance. It is almost as if she is trying to obfuscate the definition and usage of "random".

To be fair and completely truthful, most other general use English dictionaries, including my personal favorite, The Oxford English Dictionary, one of the most complete compendia of the English language, define the statistical sense of "random" to be the uniformly distributed probability case. However, I'm really not interested in what the plurality of dictionaries say what "random" means as I have been nothing but explicit that I am using "random" in so far as it describes entities that are similar if not identical to "stochastic processes", which themselves have a rigorous mathematical definition.
 
Correa Neto said:
Yes, but note this peculiar fact:
If you set the algorithm to "evolve" say, high-altitude slow aircraft with great autonomy, the final product probably will be a light airplane with large wingspan and engines adjusted to work for a long time with small fuel comsumption and a relatively small rotation regime. In this sense, the result is "predictable", and the IDer could say its not a random proccess. Alternatively, he/she could claim the Intelligent Designer set the rules and the goals...
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It is highly likely that that would be the solution. Until one starts evolutionary algorithms on systems, where the goal is to reproduce, and with a randomly changing environment evolutionary algorithms are going to produce largely predictable outcomes.

Even in that situation, there will be some generalisations that one can make, see my previous posts for my examples...

Jim
 
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