Can death ever be a good thing from an evolutionary perspective? Even though natural selection is all about survival and reproduction, the death of individual cells within a multicellular organism can be beneficial. For example, as the organism grows or when in stressful environments, some cells are no longer needed. Without the ability to kill off such cells organisms suffer. Indeed, such an inability leads to cancer. And so it is not surprising that plants and animals regularly kill off unneeded cells. In fact, their cells have an elaborate and sophisticated programmed cell death (PCD) apparatus. When the signal is given an amazing process of dis assembly begins where the cell's molecular structures are chopped up in an orderly manner. Like the engineers who know just where to dynamite a bridge, the PCD apparatus destroys the cell with remarkable efficiency.PCD is yet another example of biology's elaborate and sophisticated designs that evolution struggles to explain. But new research has added yet more trouble for evolution. It turns out that PCD in plants and in animals have some similarities that further indicate, from an evolutionary perspective, that PCD was present in the common ancestor of plants and animals.
But the common ancestor of plants and animals was not a multicellular organism--it was a unicellular organism. Why would evolution design a cell that can kill itself?
It is yet another example of an evolutionary expectation gone wrong. And, in turn, evolutionists will react with another silly just-so story. Perhaps it will go something like this:
Competition for resources was fierce even in the early phases of evolutionary history. Before cells aggregated to form multicellular life, they existed in tightly knit communities, which provided various benefits including easier defense against predators, reduced susceptibility to environmental threats, and the facilitation of resource sharing as an insurance against the spatial or temporal resource famines that cells going it alone might face.
The cost of such cellular communities was that particular cells may need to be sacrificed occasionally for the good of overall community. For instance, perimeter cells facing environmental threats would have an increased chance of death and so their resource consumption would be inefficient. Better for them to cease consumption and conserve resources needed by the remainder of the community. Also, cells in the crowded interior of the community may occasionally face resource deficits and, again, cell death would improve the fitness of the remainder of the community.
These scenarios parallel the altruism that has been observed in insect communities, and there is no reason such evolutionary dynamics were not present in the unicellular world. This is an instance where evolutionary theory sheds light on itself, as what we learn about the evolution of observable extant species may apply to the evolution of unobservable, deep-time, species.
Of course the evolution of unicellular PCD relied on environmental signals to initiate the PCD. Such signals could not be too predominant or community wide, for they would have the potential to kill off the entire community. Nor could the PCD signaling be too rare. Most importantly, of course, the selected PCD signals would need to correlate with threats and stresses that could be countered with PCD. Resource concentration reduction is an obvious candidate PCD signal, but our research investigates several other, more subtle and more discriminating, environmental signals which could have led to the evolution of PCD in early life.
See how easy bad science is? One could get used to it.
Hasn't just such behaviour been observed in present-day microorganisms, such as yeast?
ReplyDeleteanonymist,
ReplyDeleteyes, although whether yeast does it as part of its normal life cycle (without artificial induction from things like ammonia) is debated. the best example is slime molds, which live as single cells under good environmental conditions but join together to form multicellular bodies undr harsh conditions. some cells die, apprently under the control of other cells, and form a stalk of dead cells that support meabolically less active spores. so in this case PCD is present in single celled organisms but only occurs when they become multicellular.
for a more serious (but somewhat dated) treatment than Cornelius has provided of this important topic see:
http://nature.com/cdd/journal/v9/n4/abs/4400950a.html
Here's one problem with the evolved hypothesis for repair and apoptosis (programmed cell death):
ReplyDeleteQ: How can a repair mechanism arise without pre-knowledge of correct system state?
A: It cannot. Not when the damage caused interrupts system functions and when corrective facilities are this specifically complex.
In software development, programmers build what we call "exception trapping" mechanisms.
Such mechanisms 'watch' a given function progress and trap errors (exceptional system events) when detected.
The trapping code then directs program flow either to analysis functions and correctional code or, if the error is minor, simply continue processing after the code block that failed (caused the exception) and the trapping code may possibly alert the user to a faulty input situation.
DNA has it's own special codes for detecting and 'catching' the exceptions that occur. Triggered by a diverse range of cell signals.
Neo Darwinian evolution (NDE) cannot explain the existence of such built-in functions.
Worse (for NDE) : Not only is there repair of damage available to the cell's system but there is even a last resort "correction" (but not repaired) measure called apoptosis - pre-programmed cell death; "a type of cell death in which the cell uses specialized cellular machinery to kill itself; a cell suicide mechanism that enables metazoans to control cell number and eliminate cells that threaten the animal's survival" (also plays a role in preventing cancer). Its a key process in multicellular organisms.
This too is not explicable under NDE.
So, in a more engineering like term we can look at this process as something like a control-feedback loop. Such 'loops' exist in many places in the cell; like the circadian oscillator (Paely's watch!) - "a clockwork mechanism that controls these global rhythms of transcription, chromosomal topology, and cell division."
Darwinism utterly fails to predict sophisticated repair mechanisms like these. Only pre-knowledge of correct system state can foresee and then construct code sequences that operate repairs to or destruction of faulty parts in a complex machine.
DNA is such a machine.
Happy new year Dr. Hunter!
And once again we see that a creationist argues by assertion.
ReplyDeleteThere is nothing wrong with the explanation. If natural selection is the proliferation of certain gene frequencies, and pre-programmed cell death increases certain gene frequencies (by, say, making resource consumption more efficient), then it's perfectly logical to conclude that pre-programmed cell death would be adapative.
"There is nothing wrong with the explanation. If natural selection is the proliferation of certain gene frequencies, and pre-programmed cell death increases certain gene frequencies (by, say, making resource consumption more efficient), then it's perfectly logical to conclude that pre-programmed cell death would be adapative."
ReplyDeleteThis is a good example of evolutionary thinking. Evolution is impervious to massive problems.
This is a non-problem. Nothing you have said even suggests otherwise. Your response to the explanation amounts to sticking your thumbs in your ears and chanting "NYAH NYAH! EVILOOSHUNISTS ARE STOOPYYYD!"
ReplyDeleteBut if a gene cause the death of the cell, then the whole point of the gene is to remove itself from the gene pool. So how does the gene spread through the population?
ReplyDeleteNo, it's removing an individual copy of itself from the gene pool. The frequency of that gene still increases.
ReplyDelete"And once again we see that a creationist argues by assertion."
ReplyDeleteEvolutionists automatically label anyone a "creationist" who finds problems with their theory.
Well yes, by that definition you do not qualify as a creationist, since you haven't found any problems with evolutionary theory.
ReplyDeleteI doubt that's what you meant, though.
Tyler: You merely wish there were no problems with this. But yours is only a poorly disguised defense of emptiness.
ReplyDeleteThe fact is that you cannot have error detection and correction without pre-knowledge of proper system state and subsequent planning - in any system, mechanical or living. This is not hard.
Here's how you can test your own "chance + selection" scenario for this topic fairly easily:
Write something in English in your Word processor (or on paper); deliberately make grammatical errors and typos; find someone that does not read or speak English; ask them to correct the mistakes.
See? They can neither detect nor correct.
DNA is a language.
Pretending that blind nature can build DNA from scratch without any guidance and then claiming that anomally detection and rapair mechanisms can arise by pure luck, because things can and do go wrong occasionally, is insane credulity in chance + selection - just like everything else in Darwinism!
But if the whole point of the gene is to remove itself, how does it ever become part of the gene pool? The bacteria commit suicide, so how can their genes spread. The suicide gene is only an advantage when it is used, but then the bacteria is dead.
ReplyDeleteI'm confused. Isn't there a contradiction in the following paragraph from the OP:
ReplyDelete"But new research has added yet more trouble for evolution. It turns out that PCD in plants and in animals have some similarities that further indicate, from an evolutionary perspective, that PCD was present in the common ancestor of plants and animals."
If this new research is yet more evidence for a common ancestor of all plants and animals on Earth, then surely this supports evolution through natural selection? More evidence that there was a common ancestor?
It is hardly evidence that there WASN'T a common ancestor, is it?
natschuster -
ReplyDelete"But if the whole point of the gene is to remove itself, how does it ever become part of the gene pool? The bacteria commit suicide, so how can their genes spread. The suicide gene is only an advantage when it is used, but then the bacteria is dead."
Imagine a cell in a pool which has learnt to replicate itself, but does not commit suicide. If it just keeps no living, replicating itself (and those children go on to keep replicating themselves) then sooner or later these cells run out of space, food or some other resource, surely?
Whilst in cells which replicate but also have PCD, this is certainly a less inevitable problem. Perhaps these cells will out live the first ones because they don't squander their resources.
In other words, I don't really see why NOT having PCD is a survival advantage over having it.
The suicide gene had to start in one cell, then spread thoughout the population. But if the cell kils itself, how can the gene spread? And if it only kills itself after it repoduces, then the gene is not an advantage, because it is only an advantage when the cell kills itself.
ReplyDeleteRitchie:
ReplyDelete"I'm confused. Isn't there a contradiction in the following paragraph from the OP ... It is hardly evidence that there WASN'T a common ancestor, is it?"
The problem, in this case, is that PCD is a particularly unlikely evolutionary invention for unicellular organisms. It makes sense for multicellular life, but the similarity found between plants and animals implies PCD was also present in unicellular organisms which goes against evolutionary expectations.
"Imagine a cell in a pool which has learnt ..."
Which is exactly the point of DarwinsPrediction.com. One can always patch a theory if one is sufficiently motivated. So the question is not: Has the theory been falsified? A more relevant question is: To what lengths must we go to prop up the theory?
That evolutionists would propose this idea that early, single-celled, forms would evolve PCD reveals how silly and impenetrable is the theory.
We were once told evolution selected for reproduction (and hence survival). But silly us, that's passe. Evolutionists have progressed far beyond that. Now today's sophisticated version of the theory recognizes that survival really isn't so important, and that suicide often makes sense. It is astonishing that anyone takes this stuff seriously.
I believe I have seen an actual "just so" story become invented before my very eyes. This reminds me of the many times the Ptolemaic model was patched and tweaked to the point of absurdity. So why did they (the medieval scientists and clerics)keep it instead of moving to something simpler? The Ptolemaic model's truth was dictated by metaphysical constraints. The Earth had to be at the center of everything, the heavenly spheres had torotate about it, etc. To give up on this model meant abandoning the metaphysics on which it was based.
ReplyDeleteI feel the modern, Darwin derived, explanation for the history and diversity of life is the modern equivalent of the Ptolemaic model. Does it make accurate predictions? Yes, much of the time. Does it have any serious flaws? Well...it can't have flaws, because it must be true given the metaphysical contraints modern science has inherited from the late enlightenment period. Any potential flaw can be fixed by a just-so (read useful fiction)story.
"We were once told evolution selected for reproduction (and hence survival). But silly us, that's passe. Evolutionists have progressed far beyond that. Now today's sophisticated version of the theory recognizes that survival really isn't so important, and that suicide often makes sense."
ReplyDeleteThe way I understand it, it's not that PCD throws a spanner in the calculations that reproduction is the only goal, but that suicide is PART of reproduction (and hence survival).
"So the question is not: Has the theory been falsified? A more relevant question is: To what lengths must we go to prop up the theory?"
If I may go off on a tangent for a moment, it was once thought that the Sun and its planets went round the Earth. But the calculations of how the planets moved became very complicated indeed. It soon became clear that it made far more sense if the planets including Earth went round the Sun. A simpler, and therefore preferable explaination of the data.
However, this model was still not perfect. Uranus (the then outermost discovered planet) did not move in quite the way it should. At a certain point it wobbled. Faced with this, Alexis Bouvard concluded there must be an eighth planet affecting Uranus's orbit at that point.
Now this may well have sounded, as you put it, like 'a prop for the theory' in the face of a failed prediction. But that does not mean it was wrong. In fact this 'prop' turned out to be perfectly justified - on inspection there WAS an eighth planet.
The point is that this, surely, is precisely how science develops - keep trying to falsify a theory. When you find a piece of evidence that you did not expect, ask whether the original theory CAN accommodate it. In other words, does it falsify the theory, or does the theory need a tweak. And there is nothing wrong with a tweak. It simply hones the theory to centre in, little by little, to the truth of how the universe works. This is perfectly scientific and I can barely think of a single theory which has survived centuries of scrutiny without being tweaked, honed, or as you put it 'proped'.
Ritchie,
ReplyDeleteI am all for tweaking a theory. There is no reason to discard a theory just because it has a few problems. But what happens when the metaphysics behind the theory rule out the existence of problems in the first place? In the 15th century, the scientists and clerics were limited by the metaphysics of the time. No model could be given ontological status unless it had the earth at the center and the heavenly bodies in circular orbits. Copernicus used the same data the Ptolemists used, but invented the heliocentric theory (I know you know that...just building a story here...not trying to insult you.) But it was more that a new model, it was based on a new metaphysic. The establishment at the time allowed his model as long as it was just a useful fiction; "Saving the Phenomena" it was called.
Now how do I know your just so story for cell death is not a useful fiction? I just cannot see how it could ever be falsified given the metaphysics behind science today. Your tweak might be real, but there is no way to tell if it might be false. The metaphysics dictate it must be true.
"I am all for tweaking a theory. There is no reason to discard a theory just because it has a few problems. But what happens when the metaphysics behind the theory rule out the existence of problems in the first place?"
ReplyDeleteUmmm, I'm not really sure I know quite what you're getting at here. The metaphysics of evolution rules out the existence of problems? That's not true. The theory of evolution is highly falsifiable. Just because it hasn't been falsified, doesn't mean it isn't falsifiable - it just means the evidence supports the theory.
"Now how do I know your just so story for cell death is not a useful fiction? I just cannot see how it could ever be falsified given the metaphysics behind science today."
I know I'm probably being dumb, but what do you mean by the 'metaphyscics behind science today'? What is the metaphysics behind science today?
Ritchie,
ReplyDeleteExplaining this will take some time because I am not that efficient at it. Bare with me.
Let's start with the question A hypothesis is derived from a theory. Is this hypothesis real or just a useful fiction?
Here is flow chart of the options.
The confirmation route is not a good way to answer the question because there is epistemological ambiguity between routes 1 and 2.
The disambiguation will have to occur through a falsification. Hopefully a fiction will eventually stop being "useful" and expose itself as wrong. But falsification is more complicated that just looking for failed predicitons. Routes 3-7 show the possibilies.
Now, pretty much every person I have talked to who defends the modern evolutionary synthesis is open to route 7. Of course route 6 is the prefered way to go, but part of being an objective scientist is to recognize the modern synthesis itself might be wrong.
But, for evolutionary explanations, there is a metaphysical problem with route 7 that few modern scientists seem to realize. This problem effectively eliminates it from the flow chart, forever trapping the evolutionist in his/her paradigm.
Modern Science has two primary axioms it inherited from the late enlightenment period. Methodological Naturalism (MN) and Uniformitarianism (UF). At the root of evolutionary explanations is the Prinicle of Continuity. This link explains it.
The Principle of Continuity
The Princile of Continuity is mandated by the axioms. There can be no other way without changing the axioms. That means any explanation for life's diversity will always have to follow this principle. Sure Darwinism might me replaced, but the next explanation will have to follow continuity.
What I am ultimately getting at is not if evolution is true (it could be), but how the core principles it is build upon could ever be proven false. What if God did just "Poof" things into existance in a progressive fashion? That option can never be explored because it violates the continuity principle. To explore it, the axioms will have to change.
Okay, that's rather complicated.
ReplyDeleteBut I think you're tying yourself up in knots for no reason (other than to make supernatural occurences sound like viable explainations).
Ultimately, science is a way of knowing the world. We make hypotheses about how the world might work, and then go out and test to see if they are correct. This is the essence of science.
Take MN and UF - they are fundamental assumptions upon which science is built. The ideas that the universe is material is an absolutely necessary prerequisite for doing science.
If we allow the supernatural as a possibile explaination for natural phenomenon, then we are left with no way of seperating the true ideas from the fanciful ideas.
An example - imagine we are atheist scientists. We perform an experiment - what will happen when we drop a ball? We perform the experiment. It falls. Very interesting. Assuming, as we do, that the universe is built on constant, materialistic laws, we can conclude there is a force acting to pull the ball down. We can then perform further experiments to find out more about it.
Now imagine we are scientists who allow for supernatural explainations. We do the same experiemnt, but we can draw no conclusions from it, and all further experiments are pointless. The fact that the ball fell might be a 'miracle' or an example of a natural law being violated. How are we to determine when things are behaving in accordance with natural laws and when they are breaking natural laws? It does a scientist absolutely no good at all to believe in a being who created natural laws if they also believe that same being can VIOLATE those laws. Allowing for the possibility of the supernatural in explaining supernatural phenomenon leaves us with no way of winnowing the fanciful rubbish from the truth about how the world works.
Modern science (not just biology, but every field of science) does indeed assume MN and UF are true, and these are assumptions. However, the fact that modern science is so damn productive kinda suggests that it is correct in these assumptions. The fact is, science gets results - medicines, operations, technology, etc. Surely this indicates that it is correct?
D'oh!!
ReplyDeleteThat should be:
"Allowing for the possibility of the supernatural in explaining NATURAL phenomenon leaves us with no way of winnowing the fanciful rubbish from the truth about how the world works."
Hi Ritchie,
ReplyDeleteOh yeah...its complicated. But completely worth understanding. Thanks for hanging in there with me.
First, I completely agree that explanations with supernatural components have a whole set of difficulties. But pointing that out does not resolve the difficulties the MN and UF axioms create for one working within them. I did not see any attempt on your part to resolve or aknowledge the falsifcation problems the axioms create.
Let me ask you a question. Is it acceptable in science for a preconcieved idea to dictate the route evidence can follow?
Look at this scenario.
You see, I think you are not open to any explanation of PCD that does not include continuity. The same applies for your Cambrian Explosion discussion. This is not because you intentionally have lost objectivity. But is the result of the not having falsification route 7 available.
"But pointing that out does not resolve the difficulties the MN and UF axioms create for one working within them. I did not see any attempt on your part to resolve or aknowledge the falsifcation problems the axioms create."
ReplyDeleteLet me address that now. I'll start with the link you just posted in this last comment.
The flaw in the reasoning is when it states that confirmation can happen if the hypothesized missing fossils are found, and that falsification may occur if they are not found. All this is true, but the theory may also be falsified if fossils are found which do not fit into the pattern necessitated by the explaination given. Positive falsifying evidence. This evidence need not fit in with any other theory or any theory at all. It just needs to falsify the one given.
This is well known in the field of science, and in fact when testing a hypothesis it is considered correct to actively try to falsify it rather than confirm it. Finding supporting evidence is one thing, but finding contradictory evidence is another. And if you don't look for it when testing your theory, you can bet your bottom dollar your fellow scientists will when peer reviewing it.
Positive falsifying evidence is not subject to MN, UF or this continuity principle because it doesn't need to fit in with any theory. It just needs to be, to quote the common phrase, an inconvenient truth.
"Is it acceptable in science for a preconcieved idea to dictate the route evidence can follow?"
I'm not quite sure if you worded this the way you wanted to. How can evidence follow a route? Evidence is just data - raw facts about the world. A preconceived idea may affect the evidence we seek - we seek evidence to test the idea. But it should not affect our interpretation of new data - we should always be objective when we do that.
"You see, I think you are not open to any explanation of PCD that does not include continuity. The same applies for your Cambrian Explosion discussion."
I disagree. What explainations of PCD are on offer? Or for the Cambrian Explosion? I would gladly consider any you offered.
My scientific mind wants to say: "But whatever explainations you propose, I would ideally hold them to a high standard of evidence. They would need to be ideas which not only accounted for the evidence, but also made tangible predictions so that we could test them."
However, I can see that without MN and UF, we cannot make predictions. What is true today might be false tomorrow. The laws of physics may be re-written at any time. Without MN and UF it is as reasonable to expect the sun to rise over the horizon tomorrow morning as it is to assume an enormous vase of flowers will.
So how exactly would we go about showing that these explainations were correct? It seems without MN and UF, we have no way of doing that.
Ritchie,
ReplyDeleteWith all the writing you must have missed it when I wrote "One way" falsification can occur.
Of course there are other ways, but they all suffer from the same problem.
Lets say the inital hypothesis is made as presented, but evidence is found that shows a different pattern. What do you mean by "pattern"? Can you give me an example of a pattern that would not be based on continuity? I don't think you can.
As for the word "route". I picked that specifically to allude to the routes of falsification diagram. New evidence, if falsifying, will have to be dealt with in one of those ways. Did I leave a route off the chart? (thats possible.)
Finally, the issues you raise about MN and UF being necessary to do science seem to disregard all science up tp the enlightenment. You do realize that before...ummm...lets say the late 1700's, those axioms were not in place.
"With all the writing you must have missed it when I wrote "One way" falsification can occur.
ReplyDeleteOf course there are other ways, but they all suffer from the same problem."
They do not. That's my point. Positive falsifying evidence does not suffer from the what you seem to think of as the problems of MN and UF. Positive falsifying evidence would simply be observations of the world which happen to falsify the theory in question.
"Can you give me an example of a pattern that would not be based on continuity? I don't think you can."
Neither do I, but I'm not claiming to.
Let's use the example you gave. Supposing I discover a fossil between two already discovered. Suppose I could abslutely prove genetically (somehow!!) that my new fossil was the descendant of the older discovered one and an ancester of the younger discovered one. Yet it did not share the characteristic features of either. It was a 'missing link' between the two, but did not fit in with the expected pattern of accumulated features we see in its ancestor and descendant.
This piece of evidence would then falsify your common descent theory. This evidence is not subject to problems of MN or UF because it does I am not claiming it fits in with any pattern or competing theory. That is the point. It is simply an inconvenient piece of data.
"As for the word "route". I picked that specifically to allude to the routes of falsification diagram. New evidence, if falsifying, will have to be dealt with in one of those ways. Did I leave a route off the chart? (thats possible.)"
Ahh, I understand now. Okay. In that case, my answer to 'Is it acceptable in science for a preconcieved idea to dictate the route evidence can follow?' would be 'ideally no, though I'm sure it does happen in practise'.
But as a couple of side comments on your chat, I do not believe 1 and 2 are valid routes. Theories and hypotheses are never confirmed (assuming you intend the word to mean something like 'proved'. If you intend it more in the sense of 'agrees with new data' then I retract this objection). Also, how exactly does route 7 differ from route 6?
"the issues you raise about MN and UF being necessary to do science seem to disregard all science up tp the enlightenment. You do realize that before...ummm...lets say the late 1700's, those axioms were not in place."
The priciples of modern science might not have been established formally until the enlightenment, but it is absurd to suggest that up until this point no-one ever thought critically. Besides, it is a relevant point that our scientific understanding has absolutely mushroomed since roughly the seventeenth century. Before that, objective knowledge about the world only grew by tiny degrees from century to century.
Ritchie,
ReplyDeleteThe very fact that there is a lineage of any kind is continuity. You may be confusing this principle with common descent, which is one type of lineage. All you did was substitute one family line for another. That's all. But, you did do a great job of proving my point. Within the axioms, you cannot explain the existence of a new fossil without appealing to a lineage of some sort.
Let me help you out a bit. The opposite of continuity would be if some organism just "poofed" into existence from nowhere. It had no ancestral lineage what-so-ever. Neither was it the product of abiogenesis. No particle/force cause produced it.
Ifsuch an event did occur in the past, modern science would completely miss it. Lineage is assumed because MN and UF mandate continuity.
Thanks for the discussion, it has been great. Sometime I hope to discuss science pre-enlightenment. You might be interested in the famous exchange between Isaac Newton and Gottfried Leibniz (carried on via Newton's go-between guy Samuel Clarke). Newton did not follow MN or UF, but somehow managed to pull of a good bit of science.
Now you tell me,
Ack....I have not idea how the "Now you tell me," got in there. Please ignore it.
ReplyDeleteImagine a fossil really did poof into existence, then how fantastically unlikely would it be that it just happened to show highly complex features which were intermediate between those found in other fossils of its kind which we find in slightly earlier rock and slightly older rock?
ReplyDeleteThat would be truly phenominally unlikey. I appreciate the irony here, but it must be equivalent to the odds of a fully functioning eye happening to appear by pure chance.
Do you really consider this explaination more likely that the explaination that there is some genuine relatedness between the fossils?
Science wouldn't 'miss it' if evidence just poofed out of thin air. But it does assume this doesn't happen. It seeks to explain the presence of things.
But if you would rather believe a theory which is based on the belief that things poofing into existence really happens, then what evidence can you provide which suggests this really happens?
Or are you simply clinging to this idea in an attempt to rubbish the scientific method whatever the cost to logic and reason?
Your final paragraph suggests you want to end this conversation. If this is indeed the case, then thank you for the discussion too.
Newton, by the way, is a beautiful example of a scientist applying critical thinking to the world around him. If he could not have provided any evidence for his ideas, no-one would have listened to him.