luvluv

RufusAtticus:

That's funny.

Doubting Didymus:

It's probably best to assume I know nothing. Give me or reference me to as quick a guide to this as possible, if you would be so kind.


Mr. Darwin:

Frankly, no. The history of science is littered with long periods of very intelligent, capable people making very fundamental errors. Scientists have been wrong about things they study everyday, and wrong about them for long periods of time.

Oolon Colluphid (could get name that's a little HARDER to spell?)

I think you are committing the classic fallacy which I would like to avoid in this discussion. The evolutionist in his battles with literal creationists often assumes that he merely has to prove that creation isn't the product of a PERFECT, OMNISCIENT intellect in order to justify the inference that it was not designed at all.

I've always thought that was hogwash. Even the best designed human inventions display some very stupid, climsly, wasteful, and pointless attributes. This does not at all constitute an argument for the "purposeless evolution" of things like cars, computers, or bicycles.

Not pefect does not equal not designed.

I understand all that, I was only referring to the mutations, specifically the trillions upon trillions of them necessary to explain all of life. I consider it unlikely that accidental mutations could be numerous or beneficial enough to account for all the diversity of life. Natural selection upon those mutations is not as severe a barrier to me accepting Darwinian evolution as is my accepting the incredible number and utility of mutations needed to explain EVERYTHING (though I do have some doubts about natural selection as well).

Again, Intelligent Design implies only what the words imply. It is not Omniscient Design or Perfect Design. Saying that certain organisms don't appear to be absolutely perfect does not refute the notion that they were designed one bit.

Peez:

Okay, but it seemed like in your original post you explained how the cell wall was quite specified in what it would let through (only sugar). Now you are making it seem like it will let anything through, or at least that the "circuitry" that only allows in certain elements can be overriden quite easily. Which is it?

All right but again, this is much further down the line. You're comparing the first cell to register any specific reaction WHATSOEVER to light to advanced, specialized cells in the body of a human being. That cells in an organism as advanced to humans can react to light is well known to me. I am not (quite) blind. The question is how this came to be.

And even in these advanced specialized cells the reactions to the stimulus that the cells aren't "designed" to detect are fundamentally useless. Pressure makes my photoreceptors MALFUNCTION. Electricity can cause many different reactions in my touch receptors, but none of them potentially functional. Similarly, a cell membrane letting things in it is not supposed to let in, for whatever reason, seems to be more likely to cause it problems than anything else.

But this is only half the problem. What selective advantage would such a cell have? What would be the benefits of letting in any protein of a certain color?

Okay, I may be being redundant here but define "light sensitive"? What would it specifically entail? A change in the proteins shape?

RufusAtticus

So I guess that even you don't know what it means and are just parroting IDist buzz words. The point is, luvluv, that you can toss out what ever buzz words you want, but if you can't explain how they relate to biology then you're arguments are nothing but rhetoric.

theyeti

luvluv, have you explored the likelihood of a beneficial mutation given known mutation rates and genome sizes? Are you aware of the math involved?

Let's do a quick, oversimplified exercise. Given a population of bacteria with a mutation rate of 10^-6 per locus per generation, and about 1000 nucleotides per locus, thats about 10^-9 per nucleotide per generation. It doesn't sound like much. But we're talking about a population of bacteria here, so there are multiple independent trails being performed. 10^9 bacteria is a pretty small sample -- I'm not sure, but it's probably less than what you'll find in a 500ml shaker flask at good density. Now, given that E. coli can replicate every 20 minutes and a popluation of 10^9, this means that on average, every single nucleotide in the genome will mutate once every 20 min somewhere in the population. If there are any potential beneficial mutations, they will happen within a matter of a few hours at most. It is impossible that they not happen. Over a period of a few days, every possible mutation will have occured many times over. Keep in mind that we're talking about a small jug of bacteria and a few hours; over evolutionary time, the bacteria have been at it for 3.5 billion years or more with a whole ocean full.

Now this is an oversimplified example as I said. For example, you can't get just any combination of mutations in one shot -- numerous, beneficial mutations would have to occur incrementally, being spread by selection each step of the way. (And in sexually reproducing organisms, beneficial mutations from different lineages can come together.) But this is why evolution is slow and gradual. In fact, observed rates of evolution in the wild are orders of magnitude greater than what we observe in the fossil record. So if you believe there's a problem with evolution when it comes to mutation, then you need to do the math and show us where that problem lies. From all available information, if there's a problem, it seems to be the opposite of what you'd expect.

theyeti

Vorkosigan

Again, Intelligent Design implies only what the words imply. It is not Omniscient Design or Perfect Design. Saying that certain organisms don't appear to be absolutely perfect does not refute the notion that they were designed one bit.

Luv, it's not that the designs are "not perfect." It's that they are often wasteful and stupid, and reflect constraints any Designer would not need to face. Why are bat lungs less efficient than bird? Why do carnivorous plants need to consume insects for nitrogen, when other plants can get nitrogen right from the air? Why were bipedal humans designed using a four-legged body plan? And finally, why do organisms appear to belong to specific environments?

A second problem is: why are clear relationships of descent visible in the animal world, if each one is designed from scratch? According to the Design theory, each animal is a stand-alone one-off. So why do all mammals appear related? Further, if the Design hypothesis is true, why is it that BOTH independent lines of evidence, genetic and morphological, show identical relationships?

Finally, if they are Designed, why are there extinct animals?

Vorkosigan

MrDarwin

Some of my own questions about "Intelligent Design" are:

1. Does "intelligent design" account for everything we see in the natural world around us, or only some things? If the latter, how do we tell the difference?

2. How many different original designs were there, i.e., was there one originally designed cell from which everything else has evolved, or were all the phyla designed independently, or perhaps each and every species?

3. Did this design occur in one initial design episode, or have some creatures been designed more recently than others?

4. Have the designs of organisms been modified since the initial design?

5. Are designs still being modified?

6. How many designers are/were there? And how do we know?

7. And finally, what would an undesigned organism look like?

RBH

MrDarwin's 7th question wasHoo boy! Is that a good question! I really like that. It gets to the heart of the matter: how does one discriminate between designed biological entities/structures/processes and those that are undesigned? That is, after all, the (supposed) function of "irreducible complexity" and "specified complexity" - to make that discrimination. Has anyone ever seen any validation data on IC or SC? On ISCID a while back there were several suggestions for test materials - the Oklo reactors, the Avida simulations of evolution, and so on, but to my knowledge no IDist has gone to the work of actually validating their methodologies over a range of objects of known provenance.

RBH

GunnerJ

The problem here, to follow up on something another poster said, is that we can recognize and understand flaws in the "design" of certain life-forms.

You may say the "designer" is neither omnipotnet nor omniscient, but unless the designer of all life is not as smart and less competant than we are, the design hypothesis has no excuse for these design errors.

I mean, crap, how much brainpower does it take to realise that fish living in lightless caves might not need eyes? And if this (these?) designer(s) can design all sorts of wonderful features for other lifeforms, how could he/she/it(/they) not be able to fix something as trivial as that?

It's an inconsistancy in the design hypothesis, and one that non-directed evolution doesn't have to deal with.

Doubting Didymus

You don't like making my job easy do you?

Right, Have a look at This diagram from about the middle of this page. The copyright is mentioned under every picture. "Purves et al., Life: The Science of Biology, 4th Edition, by Sinauer Associates (www.sinauer.com) and WH Freeman (www.whfreeman.com)". I don’t think I can actually display it here.

The page itself isn't the best place to go for a simple run down, however. Most of the information we are talking about is at the undergraduate first year level, which is fairly deep as a starting point. I'll explain it myself as best I can.

On the diagram, you'll notice that the membrane isn’t “made of” protein, but that proteins are intricately folded molecules embedded IN the membrane, which is made of molecules called phospholipids. Those are the little round things with two tails you can see in two layers. The phospholipid part is the bit that peez is talking about when he says that the membrane is highly specific about what it will and wont allow to cross it. Whenever the cell needs to import something other than water, charged hydrogen ions, molecules that are hydrophobic (lit. water hating), and a few things like that, it needs to employ the proteins that traverse the membrane to do it. There is a protein for practically everything.

This is universal to extant organisms, because it is the (more or less) direct result of DNA. Ultra-swiftly: DNA builds an RNA template, the RNA moves to a ribosome, which translates the code into a chain of amino acids, which is a protein. The folding of the protein is determined largely by the order of amino acids in it. Thus, when a mutation occurs in the DNA, it sometimes has an effect on the folding of the protein that that part of the DNA codes for.

Yes, that’s about right. Let me expound: we are thinking about one of the trans-membrane proteins in (probably) a nerve cell. Imagine it’s a heat sensor. Now this protein has a hole in the middle, which admits, say, calcium (a commonly used molecule for cellular messages). Its usually closed, but it opens when it heats, which allows calcium into the cell, which then does a lot of things, but put simply, it stimulates the nerve cell to send its electric signal, which the brain of the organism translates as heat. What we imagine happening is a mutation, in the DNA, which puts a slightly different order of amino acids in the protein. This might have any number of effects. It might make it permanently open or closed, or otherwise useless. It MIGHT make it slightly less stable. At first, that sounds bad, but it might easily make the protein susceptible to open to things that aren’t heat, but are like it. It might now open not only when heated by air, but when heated by light bombardment. Think about what this simple mutation means for the organism. Their heat sensors are working normally, but they are ALSO reacting to light. Imagine this in some sort of starfish, which normally responds to heat by moving away from it. That starfish will now also instinctively move away from sunlight. In other words, by a single simple mutation (this might be as basic as a point mutation, which happen all the time), making one of its proteins unstable, the lucky starfish is gifted with the ability to hide.

The gene for that protein might be duplicated at some point, and if so, the two proteins might then progress in different directions. One of them might continue to mutate in such a way that it begins to lose its ability to open in response to heat, essentially making it that bit more specific to light stimulus, without having to worry about losing its heat sensing ability, because the original molecule remains unchanged.

At all times, we are talking about minute alterations to protein structures. Nothing drastic ever has to occur.

I hope I’ve explained the basic idea sufficiently in under seven hundred words. Have I left anything too murky?

MrDarwin

Two more questions:

8. Are organisms designed to survive in specific environments, or have they evolved naturally to be adapted to those environments in which they find themselves? How can we distinguish between the two possibilities? And related to this,

9. what is the relationship between design and biogeography?

I can't comment much on animals, but among plants, at least, biogeography and genealogy (as originally deduced from morphology, and for the most part corroborated by genetic studies) are very strongly correlated, especially in groups that are relatively poor at dispersing. Two especially distinctive examples are bromeliads and cacti: both families are large (i.e., with many species) and specialized (although members of both families are adapted to a wide variety of ecological niches, in some cases exquisitely so). And both families have natural distributions restricted to the New World although there are plenty of suitable habitats in the Old World (as demonstrated by the prickly pear becoming an introduced pest in places like Australia). In the Old World these suitable habitats are occupied by plants from other families entirely.

So... was there one original cactus species and one original bromeliad species, and the rest evolved in the New World from these original species? (In other words, the distribution is a logical consequence of their common origin, with members of each group becoming adapted to different habitats and ecological niches.) Or did the designer have some reason to design many different cacti and many bromeliads, but for some reason restrict them to the New World? And what might this reason be?

In a nutshell, with several dozen genera and several thousand species, adapted to many different habitats, just how much of this diversity and adaptation is entirely natural, and how much of it is due to design? And how can one distinguish between the two possibilities?

MrDarwin

"Intelligent Design" will ultimately fail not because scientists are hostile to it (although by and large they are), not because scientists are atheists and agnostics (many are, but many are not, and accept evolution anyway) but because it simply isn't science. Science proceeds by asking questions about the world around us and by trying to answer those questions. These answers are hypotheses. And for any hypothesis to pass scientific muster, it must be testable. luvluv, how is ID tested? It must be falsifiable. luvluv, how can ID be falsified? It must make predictions. luvluv, what predictions does ID make? And finally, a hypothesis must make sense outside of itself: it has to be consistent with other things that we know to be true.

As near as I can tell, ID is one big argument from ignorance. Lacking specific knowledge of how something evolved, the ID proponents say it cannot have evolved. But the only way such a hypothesis can be tested or supported is by looking for more cases in which we are ignorant of precisely how something came to be, while hoping that the previous case isn't falsified by evolutionary biologists. If ID has legs, it's only because scientists simply don't know everything (and there are only so many scientists to work on various questions, anyway).

What predictions does the ID hypothesis make? Does it give us anything where we can say, "if ID is true, then when I perform such-and-such experiment (or make such-and-such observations), here is what I expect to find." luvluv, where is the predictive value in ID? I'm at a loss to find any.

And finally, does ID explain anything else in biology? Does it help explain the morphological, biochemical, and other patterns we see among related organisms? Does it explain the patterns of biodiversity and distribution in time and space we find in the fossil record? Does it explain the biogeography of living (or for that matter extinct) organisms? As far as I can tell, ID proponents have ignored all these other biological questions because they are so dazzled by their inability to explain how something could have evolved.