Optimal designs, rugged fitness landscapes and the Texas sharpshooter fallacy

The thing is that evolution in the sense of change over time is certainly a fact. But evolution in the sense of an blind and unguided naturalistic process is an hypothesis, certainly not a fact. And the number of people supporting an hypothesis is powerless to transform it into a fact. The history of science is full of theories that were once supported by a large consensus only to be later proven false. As Einstein noted “In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual.”

In itself, an inference cannot lead to a fact. For an inference to lead to a fact, the conclusion drawn must be independently confirmed/validated, for example through empirical observation or experimentation.

How would you distinguish your gene duplication scenario from molecular convergence ?

Nevertheless it is a fact that there is as yet no viable scientific alternative, or any sign that one is one the way.

And I note that you seem prone to making indefensible or even false claims on the authority of a single person. We have yet to see any evidence that the fitness landscape for the tetrapod limb is rugged enough to prevent evolution finding “optimal” solutions. Nor do we see any reasoning to support the idea that the basic design required any forethought;

1 Like

That’s an inference too, actually. But yes that’s a fact also.

Like the idea that the weather, flow of water molecules in a river, or formation of clouds are also blind and unguided naturalistic processes? You’re taking the fact-as-proof approach to facts here it seems

I suppose it’s progress of a kind if you can accept evolution under the idea that it was somehow invisibly and undetectably guided along by God or something, compared to denying life, proteins, or the vertebrate limb could have evolved at all because of your misapprehensions about fitness landscapes.

So let’s bet on the conservative political culture-war institute that never does any real science, but just writes blog-posts and makes youtube videos, instead of trusting essentially the entire branch of biological science? C’mon dude.

But evolution over time is a fact, which was alighted upon by an inference. Experiments produce results that, by inference, we make conclusions of fact from. Even observation must, ultimately, be supported by inferences from limited data about reliability, accuracy, precision etc.

One way would be to make a phylogenetic tree of the phages and show how the D2 domain has diverged over time in different lineages, rather than having independently converged many times on a similar shape and sequence, which would be really strange for two different domains in the same single protein.

1 Like

As I’ve already said at 30, what is remarkable to is that (according to Burgess source paper), the vertebrate limb pattern is so versatile that it is actually highly optimal not just for arms and legs but also for flippers and wings . If true, under the common descent paradigm, this would certainly suggest that foresight, ie., intelligence, has been involved when the vertebrate layout first appeared in the history of life. After all, natural selection is expected to hone a structure to suit its current function, not to suit some future function.

As I’ve already said at 30, what is remarkable to me is that (according to Burgess source paper), the vertebrate limb pattern is so versatile that it is actually highly optimal not just for arms and legs but also for flippers and wings . If true, under the common descent paradigm, this would certainly suggest that foresight, ie., intelligence, has been involved when the vertebrate layout first appeared in the history of life. After all, natural selection is expected to hone a structure to suit its current activity, not to suit some yet non existing future function.

And I was fully aware that you had written that.

It is hardly adequate reasoning. That the basic design happens to be adaptable does not in itself suggest any foresight. Certainly not when the basic design is quite simple, as it is in this case.

Therefore my statement stands.

2 Likes

If intelligence was evolved, when why all the mucking about with intermediate forms? Why not design the finished product and get on with other business? For that matter, why not be innovative, with turbines for flight and hydro jet propulsion for the water?

Meanwhile, humans are stuck with the sub-optimal evolutionary consequences of bipedal movement, with weak knees and a tendency toward lower back problems. Someone could write a book about this …

2 Likes

Let’s agree to disagree

In other words, highly evolvable.

But among species more broadly (as opposed to among individuals in a population), those with more evolvable traits are also expected to outcompete other species. There can be multilevel selection.

2 Likes

You should be cautious with this argument from suboptimality, for in biology optimality seems to be the rule rather than the exception. Note that I see the research on optimality as a very fruitful endeavor for intelligent design.

So much for Einstein and the authority of a thousand being worth less than the reasoning of one.

Unless you’re prepared to concede that you citing the once-removed-authority of one is worth less than the reasoning of my right middle finger.

2 Likes

Got any actual statistics on that?

It is, for example, not true for enzymes.
Bar-Even A, Noor E, Savir Y, et al. The moderately efficient enzyme: evolutionary and physicochemical trends shaping enzyme parameters. Biochemistry . 2011;50(21):4402-4410. doi:10.1021/bi2002289

3 Likes

Let’s agree that I was right - as your failure to provide the necessary elaboration demonstrates. Jumping to conclusions is not valid reasoning and that’s all you offered.

1 Like

On due consideration @Giltil’s argument is even worse than I thought…

Natural selection will not take future uses of an adaption into account - neither favouring nor avoiding them. @Giltil failed to provide any reasoning to support the idea that the solution was favoured because of the future use - the original problem I identified.

However the basic design is supposed to be optimal for the original function, too - and natural selection can land on that solution for that reason. Indeed a premise of the original argument was that the designs would be chosen completely independently - for their present function. On this assumption there is no reason to think that future functions are relevant at all, unless it is the case that natural selection would avoid a solution because it is also optimal for other uses. Which it will not do.

5 Likes

I don’t honestly see what is so remarkable about that. The limb first evolved to propel an animal thru water. To modify it so that it can also propel an organism on the ground or thru the air seems trivial to me. As, in fact, it is as it only requires changes to the relative size of some of its components. Of course, if it wasn’t so trivial, then possibly nothing would have evolved to leave the water. Then you would be marveling at how “remarkably” well-adapted you were to an aquatic environment.

Which is just another way of saying “Texas Sharpshooter.”

9 Likes

Others have alreadyreplied to that. I will add only that “research on optimality” requires some sort of testable hypothesis for the design of optimality which is completely lacking in all of ID. In the word of W. Dembski*, “ID is not that kind of science.”

* Pretty sure it was Dembski, but I can’t find a source just now.

4 Likes

What is remarkable to me is that the vertebrate limb layout (or architecture or plan) that first appeared in an ancestral tetrapod happened to be the best general architecture for limbs of the other vertebrate groups that appeared latter in evolution, such as the flippers in whales, the wings in birds or the legs in humans. Within a CD framework, this is suggestive of foresight.

Compared to what other architectures? Has there ever been an exhaustive competition between a large ensemble of possible limb architectures? This claim looks like a pure assertion to me.

3 Likes

Not really. If it is the optimal design for the original function - as is claimed - then that would be sufficient reason to choose it even assuming design. If the design were sub-optimal for the original use in ways that made it easier to adapt to other functions that would suggest foresight.

1 Like

What is your criteria for evaluating limb anatomy and on what basis are you concluding it’s the “best”?

3 Likes