Evolution Not Random

[Belz...]

Maybe, maybe not, but in any case it is not random by any definition, and it is a reasonable model for evolution (albeit maybe not the best one).

I agree with 1) and 2). 3) and 4) are probably correct too, but I'd quibble with the wording a little (particularly 4))

I'm confused. "Not random but a reasonable model for evolution", but you agree with 1) that includes random events. Did I miss something ?

 

[sol invictus]

I'm confused. "Not random but a reasonable model for evolution", but you agree with 1) that includes random events. Did I miss something ?

Meadmaker asked for an example of deterministic model for evolution, so I provided one. It's reasonable in the sense that it will evolve and could produce results which look pretty much like those of models based on random or pseudo-random number generators.

However it's rather contrived, and as I said before I don't think it's the best model - both because the way it functions is a less accurate reflection of the real process than a random or pseudo-random model would be, and because I expect its results to be less robust in various ways.

 

[cyborg]

*Sigh* Does no one here get the class/instance distinction?

When one says, "it is more accurate to model X as a probability," one is talking about the entire class.

When one says, "it is more accurate to model X as a system," one is talking about an instance.

Simple question:

If you want to see how a game of Snakes and Ladders actually progresses what method do you use? If you want to talk about all games of Snakes and Ladders what method do you use?

Is X random or non-random?

 

[Apathia]

Why has the Theory of Evolution become so complicated that no layperson can understand it or speak of it in a way that isn't way off base?

Is it that only a handfull of especially clever biologists can grasp it?
Has it become like Quantum Physics, bound to just confuse the masses and leave them vulnerable to Bleep?

Will I be OK talking about it, if I just parrot Dawkins, making sure I quote him directly?

There are science professionals speaking in this thread, yet they don't agree about the basics of the process. What's a layperson to do?
Join the Klienman Club?

 

[Fredrik]

I have answered your question; you just didn't like the answer.

No, the problem was that your answer was wrong.

Your definition of "random" still implies that all real-world systems are random. That's why Sol asked that question, and I suggested that you change the definition.

 

[sol invictus]

Why has the Theory of Evolution become so complicated that no layperson can understand it or speak of it in a way that isn't way off base?

I don't think it has gotten more complicated, at least not in its essence - just more detailed and better understood. I recall understanding the basics pretty firmly (certainly up to the level of the discussion here) after reading the unit on evolution in my high school biology text, so I don't think it requires scientific training.

There are science professionals speaking in this thread, yet they don't agree about the basics of the process. What's a layperson to do?
Join the Klienman Club?

I think almost all of us agree on the way the theory works. The main argument here is a rather idiotic dispute over semantics, sparked by the phrase "evolution is random" - which is about as true as saying "the earth is blue".

 

[jimbob]

Originally Posted by Apathia
Why has the Theory of Evolution become so complicated that no layperson can understand it or speak of it in a way that isn't way off base?

I don't think it has gotten more complicated, at least not in its essence - just more detailed and better understood. I recall understanding the basics pretty firmly (certainly up to the level of the discussion here) after reading the unit on evolution in my high school biology text, so I don't think it requires scientific training.

Quote:
There are science professionals speaking in this thread, yet they don't agree about the basics of the process. What's a layperson to do?
Join the Klienman Club?

I think almost all of us agree on the way the theory works. The main argument here is a rather idiotic dispute over semantics, sparked by the phrase "evolution is random" - which is about as true as saying "the earth is blue".

Agreed: A simple statement that "evolution is random" is wrong, because it is likely to be misconstrued as "evolution is haphazard", which it isn't.

A simple statement that "evolution is nonrandom", could lead to another error, which seems popular amongst more reasonable non-creationist Christians. This is the idea that the creator might have just created the universe, and let the inevitable laws of evolution act so that mankind would inevitably evolve. I also dislike the idea that we are at "the pinnacle of evolution", as, again that implies a steady progress towards reasoning beings, with intelligence somehow as a "goal".

Also, I would argue that a nonrandom* system would always have the identical outputs for the identical inputs, which is not what you see with evolution. (the closest we can get are probably experiments on E.Coli cultures, where the initial colonies are the same generation and from the same parent bacterium). In one experiment they were subjected to lower temperature than ideal, and left for 2000 generations. All the cultures had adapted to the lower temperature, but some that had adapted to the lower temperature also did well at high temperatures, whilst others did worse. What form the adaption took, had been essentially random, and this was only shown up when exposed to higher temperatures.

More details below:

Fast-Reproducing Microbes Provide a Window on Natural Selection


Dr. Bennett was particularly curious about how organisms adapt to different temperatures. He wondered if adapting to low temperatures meant organisms would fare worse at higher ones, a long-standing question. Working with Dr. Lenski, Dr. Bennett allowed 24 lines of E. coli to adapt to a relatively chilly 68 degrees for 2,000 generations. They then measured how quickly these cold-adapted microbes reproduced at a simmering 104 degrees.

Two-thirds of the lines did worse at high temperatures than their ancestors, experiencing the expected trade-off. “If you’re a betting person, that’s the way you’d better bet,” Dr. Bennett said. But the pattern was not universal. The bacteria that reproduced fastest in the cold did not do the worst job of breeding in the heat. A third of the cold-adapted lines did as well or better in the heat than the ancestor. Dr. Bennett and Dr. Lenski published their latest findings last month in The Proceedings of the National Academy of Sciences.

*is it possible to have a chaotic physical system that is not affeted by quantum events at a long enough timescale, and if so are all chaotic physical systems random for a long enough timescale?

Belz, do you understand the point I am trying to make, even if you disagree with it, and do you disagree with any of the points, or how would you reword them?

 

[cyborg]

Also, I would argue that a nonrandom* system would always have the identical outputs for the identical inputs, which is not what you see with evolution.

Do you understand the class/instance distinction?

 

[mijopaalmc]

Do you understand the class/instance distinction?

Can you explain what you mean by "class/instance distinction"?

 

[kjkent1]

I think almost all of us agree on the way the theory works. The main argument here is a rather idiotic dispute over semantics, sparked by the phrase "evolution is random" - which is about as true as saying "the earth is blue".

I think that the main argument at this point is mostly about everyone wanting to "win" the argument, rather than come up with a consensus about evolutionary change.

Evolution is like a river. The water is the mutation: a turbulent and upredictable force. Selection is the course that the river takes: mostly predictable, but subject to change if the river overflows its banks or forks.

A real world river's course can be predetermined. But, sometimes it surprises.

I'm wondering what the big deal with all of this is? It seems pretty straightforward to me.

 

[Meadmaker]

I think that the main argument at this point is mostly about everyone wanting to "win" the argument, rather than come up with a consensus about evolutionary change....I'm wondering what the big deal with all of this is? It seems pretty straightforward to me.

That's mostly it, wanting to win. For me, I would say it didn't start when someone said "evolution is random", but rather when someone said "evolution is not random". That somebody was Dawkins, when he said evolution was "the exact opposite of chance."

I found it curious that he was so adamant. It seemed to me perfectly clear that at the level of actual events, there was indeed a great deal of randomness. Why the strong insistence that it simply couldn't be described that way.

In participating in that thread and the subsequent ones, it seems clear that Dawkins isn't the only one. For example, the previously cited talkorigins page cites "evolution is random" as a clear sign that someone doesn't understand evolution, and hints that only a creationist would say such a thing. Some on JREF apparently agree, accusing people who use the phrase, under any circumstances at all, of being a concealed creationist.

It's quite silly, actually. I think of sheep saying, "Four legs good. Mean value 2 legs with std deviation 1 leg baaaad."

 

[mijopaalmc]

Unless there's a mutation during the initial division...

But then they are no longer genetically identical twins and therefore no longer have the same set of initial conditions. Furthermore, the event that caused the mutation was by definition random because identical initial conditions yielded different final conditions.

 

[Belz...]

Mijo, I'm getting the distinct impression that you're using the word "random" to mean whatever you want it to mean at any given moment.

 

[Tumbleweed]

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Once upon a time there were pink,green, blue, and yellow snow shoe hares, as well as white ones. For many years they enjoyed an arctic paradise until Mother Nature and her Terminator Natural Selection sent a buch of predators to live among them. Since all the pink, green, blue, and yellow snow shoe hares stood out like a sore thumb in the snow, they got gobbled up. The white ones were invisible to the predators and so they lived to procreate another day.
And that, to those who have a very simple grasp of logic is how evolution works and why it is not random>>
Is or is not this the story of natural selection. If so, I grasp it

 

[Tumbleweed]

What exactly is so astounding about Darwin's Origin of the species and why do people continue to argue about it?
For example, given the fact that all mammals share basically the same respiratory, circulatory, nervous, reproductive and digestive systems, why is it such a stretch that they had a single ancestor. It seems rather intuitively obvious to me
And does it not seem obvious that hairy mutant of a species is more likely to survive a cold snap that his kin who do not?
Compared to Newton's calculus and Einstein's relativity, evolution seems like child's play, concept-wise
Methinks the great stink about Darwin is that he appeals to people who love to see science stick it down religions throat, perhaps from a repressed upbringing of some sort
His proponents of the obvious go on forever debating with the Creationists set in their ways knowing full well that no one is being persuaded to change sides. Meanwhile the rest of us have moved on into what the mechanics of DNA change are, not whether natural selection and evolution are real or not. I offer cloning, stem cell research and bioengineering as proof of it. And while regligion might impede advancement of evolution engineering here for a while, others around the globe will press on

Basically it boils down to two options : There are random mutations among populations of species at all times
. When something "bad" happens like an ice age, some of the mutants are ALREADY prepared to make it in the new environment --
OR
The species DNA is pretty much fixed, mutations not related to predator control or climate change being a bad thing. Things stay stable until something bad happens like climate change. Either the climate change itself precipitates a DNA change/mutant capable of dealing with it, or by some as yet unknown method, the species DNA is changed to produce things like camouflage and chemicals distasteful or poisonous to predators. Ditto for the collapse of a niche and the need to develop new methods to procure nutrients from a different potential niche. It somehow precipitates DNA change
Let the experiments begin! Both options can be disproved by them

 

[mijopaalmc]

Mijo, I'm getting the distinct impression that you're using the word "random" to mean whatever you want it to mean at any given moment.

And your "distinct impression" is flat out wrong. I have always used "random" to mean "[o]f or relating to a type of circumstance or event that is described by a probability distribution". Now, most people object to this definition because they believe it makes every real-world system random (which is debatable), but I have been nonetheless absolutely consistent in my definition of "random", as all the other definition I have used (e.g., "having different outcome for the same initial conditions) ultimately derive from the above definition. In fact, it is those who insist that evolution is non-random that are using any definition they please to call evolution non-random because it is "biased", "causal", "constrained", "directional", or "non-uniformly distributed with respect to probabilities".

 

[Belz...]

I have always used "random" to mean "[o]f or relating to a type of circumstance or event that is described by a probability distribution".

Which, of course, applies to EVERYthing in the universe.

 

[mijopaalmc]

Which, of course, applies to EVERYthing in the universe.

Actually, that is one of the most persistent myths perpetuated by those who insist that evolution is non-random. While it is true that most real-world data has uncertainty, the variation in the final conditions real-world deterministic (or chaotic) systems, as well as the models that describe them, derives completely the variation in initial conditions, whereas the the variation in the final conditions real-world stochastic (or random) systems, as well as the models that describe them does not necessarily derive from variation in initial conditions.

 

[kjkent1]

And your "distinct impression" is flat out wrong. I have always used "random" to mean "[o]f or relating to a type of circumstance or event that is described by a probability distribution". Now, most people object to this definition because they believe it makes every real-world system random (which is debatable), but I have been nonetheless absolutely consistent in my definition of "random", as all the other definition I have used (e.g., "having different outcome for the same initial conditions) ultimately derive from the above definition. In fact, it is those who insist that evolution is non-random that are using any definition they please to call evolution non-random because it is "biased", "causal", "constrained", "directional", or "non-uniformly distributed with respect to probabilities".

That's very nice. But, what EVERYONE wants to know, and what you conspicuously refuse to address, is whether your probability distribution for evolutionary change looks like this:



...or like this:


...or like something else -- and if so, then what???

 

[sol invictus]

Take some time to familiarize yourself with probability theory and you will understand just how absurd the "defining 'random' as '[o]f or relating to a type of circumstance or event that is described by a probability distribution' makes everything 'random'" meme is.

Instead, they continue to construct the same, old, tired straw man that the above definition "makes everything random".

Now, most people object to this definition because they believe it makes every real-world system random (which is debatable),

I see there's been some evolution... from absurd->strawman->debatable.

I wonder if it was random?