Understanding Evolution: Theory, Prediction and Converging Lines of Evidence, Part 1

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March 8, 2012 Tags: History of Life

Today's entry was written by Dennis Venema. You can read more about what we believe here.

Understanding Evolution: Theory, Prediction and Converging Lines of Evidence, Part 1

One of the challenges for discussing evolution within evangelical Christian circles is that there is widespread confusion about how evolution actually works. In this (intermittent) series, I discuss aspects of evolution that are commonly misunderstood in the Christian community. In this post, we explore how evolution is a theory in the scientific sense, how it is supported by converging lines of evidence, and how it can make accurate predictions about the natural world, using whale evolution as an example.

Evolution: just a theory

One game that my (young) children like to play is a guessing game where both players select a character from among many choices, and by process of elimination, tries to guess the character the other has selected. Questions like “does your character have red hair? glasses?” etc., are used to narrow down the possibilities. Once you have guessed correctly which character your opponent has selected, you can perfectly predict the answer to every question thereafter (and a good many parents likely prolong the questioning to keep the hopes of victory alive for their children). When considered separately, the individual features of each character—glasses, brown hair, purple hat, and so on—mean almost nothing, since they could be features shared with other characters in the game. Only the convergence of multiple features is indicative of a good guess, and the accuracy of that guess is put to the test every time a new question is asked.

A good theory is something like this: an educated guess, based on and consistent with all past work on the topic to date. It allows you to predict how future tests should pan out. In the guessing game, there are limited options to choose from (so the analogy, like all analogies, eventually breaks down). In science, we don’t really know the true way things actually work. What we have are theories—broad explanatory frameworks supported by experimentation, that make sense of our current collection of facts—that we can use to make testable predictions about the natural world. All theories in science are provisional in that they are not complete descriptions of how the world actually works and are subject to future revision; but at the same time they are robust frameworks that can be used to predict how experiments should behave with almost boring regularity. So, far from the colloquial usage of “theory” as speculation, “just a theory” is high praise in science.

The current understanding of evolutionary theory in all its scope and diversity is far more complex than Darwin himself could have ever envisaged. (As a geneticist, I’ve often wished I could have a cup of tea with him to show him how far his theory has grown, especially given his confusion about how heredity worked.) Our understanding of how evolution works has grown by leaps and bounds since the 1850s. What is remarkable is just how much Darwin got “right” given his time and place. His main hypotheses—that species descend from ancestral forms through descent with modification, that and natural selection acting on heritable variation is a significant force in that process—remains the core of modern evolutionary theory. We’ve added a lot of detail since then (population genetics, kin selection, neutral evolution/genetic drift, symbiosis, horizontal gene transfer, molecular exaptation, and so on), but Darwin’s core ideas have produced a wealth of successful predictions. They were a very good “guess” that continues to pay rich scientific dividends.

Whale evolution: an example of converging lines of evidence

One of the things I personally find quite enjoyable about evolutionary theory is the counter-intuitiveness of some of the predictions it makes. One example that is a personal favorite, and one I often use to illustrate how evolution makes sense of converging lines of evidence, is cetacean (whale) evolution. Let’s set up the “problem” that evolutionary biology forces upon us:

  • Modern cetaceans are mammals – they nourish their young in utero through a placenta, give birth to live young, and feed newborns with milk – all features of standard mammalian biology.
  • Mammals are tetrapods – organisms with four limbs. Mammalian life shows up in the fossil record as an innovation within tetrapods, so mammals are “nested within the set” of tetrapod forms. Not all tetrapods are mammals (amphibians, for example) but all mammals are tetrapods.
  • Tetrapods are by and large terrestrial creatures. Having four limbs for locomotion is a distinctly land-based adaptation.

The “problem”, of course, is that modern whales are emphatically not terrestrial, nor do they have four limbs – they have two front flippers and a tail, with no hind limbs in sight. Yet they are mammals, which forces evolution’s hand as it were. Evolution thus is dragged, under protest, to the prediction that modern whales, as mammals, are descended, with modification, from ancestral terrestrial, tetrapod ancestors. Instantly this prediction raises a host of uncomfortable questions: where did their hind limbs go? How did they acquire a blowhole on the top of their heads when other mammals have two nostrils on the front of their faces? How did they transition to giving birth in the water? What happened to the teeth of the baleen whales? What happened to the hair characteristic of mammals? and so on. In some ways, evolutionary thinking about whales creates more difficulties than it appears to solve.

And yet, these difficulties are the stuff of science. If indeed our “educated guess” of terrestrial, tetrapod ancestry for whales is correct, the evidence will show that these transitions, challenging though they may seem, did indeed occur on the road to becoming “truly cetacean”.

Going out on a limb

Anyone who has seen a modern whale skeleton in a museum and noted it carefully may have noticed that though whales lack hind limbs, they do have a bit of bone back there where the hind limbs ought to be. While this is suggestive of a vestigial characteristic (a feature in a modern organism that has a reduced role relative to the role the structure played in an ancestral species), it’s hardly a smoking gun for evolution. Still, it’s consistent with the idea.

When we look at the cetacean fossil record, we also see forms suggestive of a progressive loss of hind limb function and structure over time, as David Kerk and Darrel Falk have elegantly explained before. Again, if one were resistant to evolutionary explanations, it would be possible (if a bit strained) to interpret these creatures as having been created directly as we find them in the fossil record. The facts that we do not see these forms in the present day, and that they seem to blur the distinctions between terrestrial tetrapods and whales might make one a bit uncomfortable, however.

Recent work on cetacean embryogenesis (how whales and their relatives develop from fertilized eggs into fully-formed baby whales) has shed even more light on the issue for modern species, however. Dolphin embryos actually have four limbs early in their development, as well as a few facial hairs, just as any good mammal should have. The hind limbs and hairs are lost later in development, and work on the molecular signaling events that halt hind limb growth and cause the limb bud to regress into the body wall have now been worked out in some detail. Moreover, early in dolphin development the nostrils are distinct and on the front of the face, and only fuse into a blowhole and migrate to the top of the head later in development. Early dolphin embryogenesis is distinctly mammalian and uncannily tetrapod-like.

… and passing the test

Taken in isolation, these facts about whales are interesting trivia. Taken together, however, they begin to form a picture entirely consistent with the prediction that modern whales are derived from terrestrial ancestors. The true strength of evolution as a scientific theory for the origin of whales is this: not that we can prove it, (for no theory is ever proven in science due to its permanently provisional nature), nor that we have full access to every bit of data we would like (consider how fragmentary the fossil record is, for example), but rather that we haven’t been able to disprove it yet, despite our best efforts. Descent with modification remains a productive educated guess that grows stronger with each investigation.

In the next post in this series, we’ll explore some additional lines of evidence for cetacean evolution that further illustrate the predictive power of evolutionary theory.

For further reading

Evidences for Evolution, Part 2a: The Whale's Tale

Evidences for Evolution, Part 2b: The Whale's Tale
J. G. M. Thewissen, M. J. Cohn, L. S. Stevens, S. Bajpai, J. Heyning, and W. E. Horton, Jr. (2006). Developmental basis for hind-limb loss in dolphins and origin of the cetacean bodyplan. Proceedings of the National Academy of Sciences 103 (22), 8414–8418. available freely online.


Dennis Venema is Fellow of Biology for The BioLogos Foundation and associate professor of biology at Trinity Western University in Langley, British Columbia. His research is focused on the genetics of pattern formation and signalling.

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Roger A. Sawtelle - #68430

March 9th 2012

Dennis,

Thank you for this series.

I hope that you will address this question, What is the nature of Natural Selection?

As is well established Darwin used the ideas of Thomas Malthus as the basis for his understanding of natural selection.  This was characterized as “survival of the fittest” by Spencer and accepted by Darwin. 

Of course survival of the fittest has been abandoned morally, intellectually, and even scientifically by most every discipline, except for evolutionary biology.

Frank Perry challenged this view in his book, Darwin’s Blind Spot, and offered symbiosis as an alternative.  He highlighted the conflict between evolution and ecology and proposed cooperation. 

My question is “Was his proposal followed?”  Your inclusion of symbiosis in you list of improvements to evolutionary theory suggests the answer is Yes.  However that is not the case with Dawkins the bellwether of popular (and academic?) evolutionary thinking. 

I even purchased a college textbook to see if symbiosis has made an impact at this level.  The answer was no.

The only ray of light seems to be that adaption and environmental niche are being used in evolutionary studies.  The Niche Construction Theory has been proposed, only to be fought tooth and nail by Dawkins. 

So what is the statis of symbiosis (and ecology) as a factor in evolutionary thought?  Is it real or a perfunctory bow?  Is Dawkins a real spokesperson today’s evolutionary thinking or a relic of the past trying to hold on to theory whose day is seriously outdated?


beaglelady - #68434

March 9th 2012

Roger,

When he answers I hope you will listen and remember what he says.


Roger A. Sawtelle - #68438

March 9th 2012

Beagle Lady,

I am all ears, so to speak.

If I don’t remember, I hope you will remind me. 


Steven Curry - #68435

March 9th 2012

Be warned that Roger holds a number of misperceptions about evolution, and about Dawkins as well. Roger says that “Dawkins has clearly and specifically rejected environmental selection”.[1] This is not true, of course, as any of Dawkins’ books on evolution attest. To pick a random example (out of probably hundreds), in “The Ancestor’s Tale” he describes the environmental selection of frogs,

”...an initial separation of some kind makes it possible for the statistical distribution of genes in the two populations to move apart. This usually results in an evolutionary divergence with respect to something visible: shape or colour or behaviour. In the case of these two populations of American frogs, the western species became adapted to life in drier climates…”[2]

[1] comment #68401 at http://biologos.org/blog/creation-evolution-and-christian-laypeople-part-1

[2] http://books.google.com/books?id=rR9XPnaqvCMC&lpg=PP1&pg=PA31


Roger A. Sawtelle - #68437

March 9th 2012

Steven,

What Dawkins is saying if you read carefully is that “separation of some kind” (which is environmental, but he avoids that concept like the plague) makes it possible for the genes to move apart which causes evolutionary change, which somehow results in adaption. 

Darwin did not know how much the earth had changed since evolution began.  He did not know that the earth had only one continent.  He did not know that the dinosaurs became extinct after a large asteroid substantially changed the climate.  These any more are all ecological changes which are matched by evolutionary changes.

Dawkins knows all this I assume, and yet he is saying that evolutionary changes occur populations are separated and their genes develop differently.  That does not explain how life forms left the oceans and began to live on land.  Or how some mammals left the land and began to live in the oceans.

Living creatures seek out new niches as they are created and they change the environment and are changed by it.  That is what ecology is all about and what Dawkins has yet to learn.  Maybe he knows it, as everyone else knows it, but he has yet to say it.              


Steven Curry - #68439

March 9th 2012

Roger, Dawkins isn’t saying that the frogs became adapted to drier climates by coincidence. He’s saying that natural selection produced the adaptations. That’s how evolution works.

Another random example from Ancestor’s Tale:

“Hairiness is one of those characteristics that can increase or decrease in evolution again and again. Vestigial hairs, with their associated cellular support structures, lurk in even the barest-seeming skin, ready to evolve into a full coat of thick hair at short notice (or shrink again) should natural selection at any time call them out of retirement. Look at the woolly mammoths and woolly rhinoceroses that rapidly evolved in response to the recent ice ages in Eurasia.”

http://books.google.com/books?id=rR9XPnaqvCMC&pg=PA67


Dennis Venema - #68440

March 9th 2012

Hi Roger, 


Natural selection is alive and well in evolutionary biology, and I’m not sure where you’re getting your notion that it is somehow in contrast to ecology and adaptation. NS is the mechanism for adaptation that allows species to exploit new niches as they become available. It’s how the environment influences genetics - by selecting the best variants for a new niche repetitively over time. Symbiosis is not “against” NS either, nor a replacement for it. I was thinking about the endosymbiotic origins of mitochondria, etc, that Darwin would not have known about. Thanks for the question. 

Roger A. Sawtelle - #68443

March 9th 2012

Dennis,

The point I was making is one of model or paradym.  Symbiosis tells how life forms live together in a real sense helping each other, such as plants providing food for animals, while these animals helping plants by spreading their seeds. 

Natural Selection, which Darwin called “the war of nature,” was conceived as conflict with the winner surviving and the loser extinct.  Many believers, myself included, do not believe that God created a Malthusian dog eat dog world.  Now this may be an exageration, but not by much, so to me the question is very real. Is nature based on conflict or mutual benefit as indicated by the water cycle and the food cycle?

Does your understanding of natural selection indicate that human beings are survival machines like all other creatures?         


Roger A. Sawtelle - #68445

March 9th 2012

P. S.

I got the notion that ecology and Darwinian NS were opposed from the popular book, Darwin’s Blind Spot and the conflict between Lynn Margulis and many of her peers.  

This as well as the anti-ecology views of Dawkins.  I still do not see where any scientist besides Margulis has summoned the courage to publically challenge Dawkins on this.   


Steven Curry - #68449

March 10th 2012

Roger, the quotes I gave above at #68435 and #68439 are sufficient to disprove your perception that Dawkins has “rejected environmental selection”. Simply read one of his books on evolution for more examples.


HornSpiel - #68447

March 9th 2012

Of course survival of the fittest has been abandoned morally, intellectually, and even scientifically by most every discipline, except for evolutionary biology.

 

Roger, It seems to me the root of your dissatisfaction with the “modern synthesis” is basically moral. In a previous discussion we talked about the possibility of “downward causation” as the source of human freewill and morality. That discussion limited such causation to the realm of intellectual ideas and choices. Are you suggesting that some form downward causation influences the evolutionary development of physical traits necessary for organisms to adapt to changing environments? How close is the following to your position:


A Good God would never have created using dog-eat-dog evolution. If evolutionary creationism can be considered Christian, it must be based on organisms changing for their mutual benefit (symbiosis) rather than some species out-competing others to extinction (NS).

If so, it seems to me you have created an a priori requirement for any evolutionary theory you are willing to accept.

Roger A. Sawtelle - #68448

March 10th 2012

HornSpiel wrote:

Roger, It seems to me the root of your dissatisfaction with the “modern synthesis” is basically moral. 

The answer to this statement is yes and no.  We are talking about a fundamental worldview where science, philosophy, and theology all come together.  That is why GoodNews in another forum said that if he had to choose between his theology and science, he would have to go with his theology and this is the way he looks at evolution, as a denial of his theology.

To understand this issue it is helpful to see it in a historical context which I thought Dennis was doing by saying that evolutionary theory had gone though many changes in the past 150+ years.  To deny this fact is absurd, but that is exactly what Richard Dawkins does when he makes Darwinism an ideology, rather than a science.

Much of the history of natural selection is involved with the question of “natural evil.”  Dawkins & Co. have resolved this question by saying that Darwinism proves that nature is evil.  The end of life is death and life has no purpose but survival and that is an illusion.

Now science, philosophy, and theology are all based on another world view.  They are based on the understanding that life is meaningful and worthwhile.  That nature is based on natural law, not random chance and that it is a cosmos, not a chaos.

Another isue that comes into play here is determinism.  Newtonian modern science is basically dterministic.  Some scientist/philosopher said that if it were possible to know the speed and direction of every particle in the universe then one would be able to predict the future in every detail. 

Obviously God is in that position, so if this were true God knows and is responsible for whatever happens.  Now with quantum physics and chaos theory we no longer have that kind of mechanistic deterministic view of reality.  Then too Einsteinian relativism has become part of our understanding of the universe.

Thus these major changes in the modern world view have taken place since Darwin formulated his theory.  They impact on science and they impact on theology and philosophy also, which is primarily why we are in this mess, because all three have failed to properly to “evolve” to take into account these changes.

Now I have tried to make it clear that for theology to resolve these issues it must go back to its basic understanding of life with the Logos, Jesus Christ as the center of its understanding of Life and Reality.

Now for science and philosophy they need to do something similar and that is recognize that the universe is a cosmos which has real meaning and purpose.  I do not know if this is an a priori or not, but it is the only way that our universe makes any sense.  But then I am old fashioned and rational enough to think that Reality should and must make sense.

I am sure that most scientists are basically pragmatic and use whatever concept seems to work without view of the consequences.  However itg seems to me that this website is dedicated to the view that ideas and concepts are important, so we need to discusion them and how they impinge on our understanding of reality.               

 


HornSpiel - #68453

March 10th 2012

Now for science and philosophy they need to do something similar and that is recognize that the universe is a cosmos which has real meaning and purpose.  I do not know if this is an a priori or not, but it is the only way that our universe makes any sense.  


Roger, isn’t this a tautology? To make “sense” and to have “meaning and purpose” seem to be essentially synonyms. I really don’t think it is useful for scientists to assume or look for is some “meaning and purpose” to inform their investigations or theories.  Is that what you are suggesting?  That is what ID does.

Much of the history of natural selection is involved with the question of “natural evil.”   

I suppose you are talking about controversies surrounding evolution, not the theory of evolution itself. To tell the truth, I do not understand the problem that conservative Christians have with NS. Isn’t that what they are advocating when they promote “free market economics” and sacrificing the safety net for the poor in order to lower taxes foo the rich?


beaglelady - #68461

March 11th 2012

Right, and it’s outside the scope of science to look for meaning and purpose.  Of course, scientists as individuals will have different world views.


Roger A. Sawtelle - #68462

March 11th 2012

HornSpiel,

I suggest that you might look at a recent book, the Atheist’s Guide to Reality, which tries to demonstrate scientifically that Reality is without Meaning or Purpose. 

What does it mean to say life has meaning?  It means first that life is predictable.  This of course does not mean that everything in life is perfectly predicable, but that the laws of science and morality work (within reason.) 

Thus science is based to the understanding that laws of gravity, time and space will work the same today, yesterday, and tomorrow, even though there once was a time when there was no laws and no nature, and probably that will happen again. 

Thus how can Dawkins may that evolution is not based on rational meaningful order, because it is based on random chance? His friend and ally Dennett thinks that human beings do not have free will, but are governed by their genes, and probably Dawkins does also. 

Neuro biology, which has become Dennett’s new speciality seems determined to prove that humans do not think.  Read the currect book Who’s in Charge?  Most people do not realize the radical thinking that is going on in science theses days.  I mean, can science prove that you and I do not think?

The problem first is the truth and the facts, not what people think they are.  Scientism based in large part on Darwinism is causing science to lose it intellectual moorings.  This is compounded  by bad theology among Christians, liberals and conservatives.  Responsible persons need to determine the truth, both scientific and theological so we can solve this basic problem tearing our civilization apart.         


HornSpiel - #68479

March 12th 2012

Roger, you are sounding more and more like Phillip Johnson in Darwin on Trial. Are you an ID proponent? The new philisophical basis you are advocating is to introduce concepts that are applicable to the social sciences (and I would have to put ecology as you describe it there too) into the hard sciences. This is what ID does as well.

We know that people cannot live consistently with a reductionist philosophy. That is a mystery that science, by definition, can never solve or explain. However if you or ID change the “philosophical basis” for science in order to make it more compatible with that truth, you are doing away with the mystery. The fact that science can’t explain our need for meaning and purpose is one of the strongest apologetic arguments for God that I know. Lets take advantage of that and not confuse the issue.




Roger A. Sawtelle - #68496

March 13th 2012

HornSpiel,

Jesus is the Logos, God’s rational Word.

Reductionist science is not rational or logical.  Bad science is as bad as bad theology.


Mike Gene - #68444

March 9th 2012

Dennis,

Symbiosis is not “against” NS either, nor a replacement for it. I was
thinking about the endosymbiotic origins of mitochondria, etc, that
Darwin would not have known about. Thanks for the question.


I agree that symbiosis is not against NS nor is it a replacement. What it does is open the door for trajectories that NS could not explore without it.   For example, would eukaryotes have ever evolved without symbiosis, even though NS would still be in play?


Steven Curry - #68450

March 10th 2012

Re: Margulis and symbiosis

Lynn Margulis deserves full credit for discovering the endosymbiotic origin of eukaryotic cells. She missed the mark, however, in claiming that *all* speciation is caused by symbiogenesis. There’s no evidence for that, and there’s no reason to believe it.

Take the example of a ring species (http://en.wikipedia.org/wiki/Ring_species). We have a continuous transition from one species to another species; all transitions are alive today so we can examine them. What’s the new symbiote? There isn’t one. As Mayr said, “there is no indication that any of the 10,000 species of birds or the 4,500 species of mammals originated by symbiogenesis.”

Margulis was also an AIDS denialist and a 9/11-truther. A contrarian like Margulis might strike upon an idea that turns out to be correct, however that does not imply special status should be given to her other ideas, especially absurd ones that are refuted by evidence.


Mike Gene - #68451

March 10th 2012

Agreed.  Just as there is no evidence to support the notion that the eukaryotic cell could have arisen without symbiosis.  Neither is there any reason to believe that.  Thus, it clearly appears that symbiosis is the key dynamic in spawning the most radical of all evolutionary transitions, while natural selection is relegated to a secondary role.



 


Mike Gene - #68452

March 10th 2012

Lynn Margulis deserves full credit for discovering the endosymbiotic origin of eukaryotic cells. She missed the mark, however, in claiming that *all* speciation is caused by symbiogenesis.

 

No, what she did was to successfully resurrect the theory for the endosymbiotic origin of two organelles – mitochondria and chloroplasts.  She not only missed the mark as you say, but missed it in proposing the endosymbiotic origin of the centrosome.  And that was both her primary focus and her original contribution.

 

There’s no evidence for that, and there’s no reason to believe it.



Agreed.  Just as there is no evidence to support the notion that the eukaryotic cell could have arisen without symbiosis.  Neither is there any reason to believe that.  Thus, it clearly appears that symbiosis is the key dynamic in spawning the most radical of all evolutionary transitions, while natural selection is relegated to a secondary role.


Steven Curry - #68454

March 10th 2012

Your comment may contain unknown levels of sarcasm. Do you believe, as Margulis did, that *all* speciation is caused by symbiogenesis? I assume you don’t believe that.

Symbiogenesis is important, even if rare. I wouldn’t say that natural selection is relegated to a secondary role. NS and symbiogenesis don’t really compete for ranking.

Think of it like an old fashioned shoot-em-up arcade game. Most of the time you are using your guns. But sometimes there’s a boss enemy for which guns are either ineffective or impractical. So you use your precious limited number of bombs on the boss.

Guns aren’t secondary to bombs, or vice versa. They play different roles. Of course, natural selection is the guns and symbiogenesis is the bombs.


Mike Gene - #68456

March 10th 2012

Your comment may contain unknown levels of sarcasm. Do you believe, as Margulis did, that *all* speciation is caused by symbiogenesis? I assume you don’t believe that.

You’re right – I don’t believe that.  It’s just that symbiogenesis is not only important, but was crucial to the evolution of eukaryotic life.  I like your arcade game analogy.  Take it further and you realize you could never beat the boss without the bombs, even if you shoot your gun continuously. In the same way, eukaryotes (capable of evolving into animals)would have never evolved without symbiosis, even if natural selection is constantly at work.


HornSpiel - #68458

March 11th 2012

Steven and Mike,


Your discussion of NS and symbiosis seems to me a matter of comparing apples and oranges. Symbiosis is a way in which new types of organism occur in the environment—a source of variation of traits. They still must be acted on by mechanisms of differential reproduction in order to become dominant. You should be comparing symbiosis with various types of genetic mutations and other sources of heritable variations such as gene flow and retroviral insertions.

Natural selection is not a source of variation but of differential reproduction. As such it is more properly compared with genetic drift , bottlenecks and founder effects.

The confusion lies, it seems, in that all these are evolutionary mechanisms

For this reason, the idea that symbiosis can somehow supplant NS as the dominant mechanism by which life evolved simply is simply illogical. To use the arcade analogy, mutation is the regular gun and symbiosis is the bomb. NS does not fit into the analogy at all since an arcade game has a goal and NS is manifestly ateleological.

Steven Curry - #68460

March 11th 2012

When we speak of selection producing change, it is implied that variation and mutation are involved—it wouldn’t make sense otherwise. When Mike says “natural selection is constantly at work”, he obviously means that variation and mutation are there, the stuff that NS works upon. It’s a shorthand. Dawkins does the same thing,

”...This would surprise those, from Darwin’s own critics on, who have complained of insufficient time for natural selection to wreak the changes the theory requires of it. We now realise that the problem is, if anything, opposite. There has been too much time!” http://books.google.com/books?id=rR9XPnaqvCMC&pg=PA257

The only purpose of the analogy was to contrast “typical” evolution (the guns) with “atypical” evolution (the bombs), with the latter acting less frequently (even rarely) but nonetheless producing effects unachievable by the former alone.


HornSpiel - #68478

March 12th 2012

Two things.

What it does is open the door for trajectories that NS could not explore
without it.   For example, would eukaryotes have ever evolved without
symbiosis, even though NS would still be in play?

It seems to me some have a preference for symbiosis from a philosophical point of view. In particular Mike’s language above implies that symbiosis somehow is a counter weight to natural selection e.g. Darwinism, the bogyman in this discussion. It is a subtle way of confusing the discussion and sowing doubt about well established mechanisms.

Second, the kind of symbiosis we are talking about here, symbiogenesis, small cells becoming engulfed in larger cells as organelles. I would imagine it is process that that would only happen in a relatively competition free environment, such as the primitive biological environment. Obviously, modern spieces evolved in a complex biotic environment, so take advantage of that if it helps survival. I was amazed to learn that “our human cells, and human DNA, are outnumbered by somewhere between a
factor of 10 and 100 by bacterial cells and DNA respectively.” http://www.ted.com/talks/view/lang/en//id/509

Nonetheless, either kind of symbiosis is acted on by NS.




Roger A. Sawtelle - #68483

March 12th 2012

HornSpiel,

You still don’t seem to get it.  Which is correct, Newtonian gravity or Einsteinian?  Newton proposed a model for gravity called “attraction at a distance.”  It was never scientitically verified, but his equations worked, so it was accepted.  Einstein was not satisfied by attraction at a distance so deveoped his own space/time model which has been scientifically verified.

Darwin developed his Theory of Evolution based on Variation and Natural Selection.  The concept of Variation works well, especially when modified to include genetic change and symbiogenesis, but the mechanism of Malthusian conflict Natural Selection has never been scientifically verified.  Still the overall theory answered many questions well.

Thus the question as to how NS has not answered until recently with the birth of modern ecology and the impact that it has had on modern thinking, it makes sense to determine if these two disciplines of how organisms develop and change aren’t closely connected, like medicine and biology.

Dennis is saying that they definitely are.  I say that the reason for this is because ecology holds the missing link (symbiosis) of how NS works.  This has been confirmed by multiple recent studies.  Natural selection works one way and one way only and it is not species struggling for ascendancy, but species working together for survival.       


Steven Curry - #68485

March 12th 2012

Roger, you first need to get your facts straight. You have several misperceptions about evolution, and you continue to resist correction on them.

Let’s take them one at a time. Are you finally ready to accept that you were mistaken in claiming that “Dawkins has clearly and specifically rejected environmental selection”? The following quote directly disproves that.

“Hairiness is one of those characteristics that can increase or decrease in evolution again and again. Vestigial hairs, with their associated cellular support structures, lurk in even the barest-seeming skin, ready to evolve into a full coat of thick hair at short notice (or shrink again) should natural selection at any time call them out of retirement. Look at the woolly mammoths and woolly rhinoceroses that rapidly evolved in response to the recent ice ages in Eurasia.” http://books.google.com/books?id=rR9XPnaqvCMC&pg=PA67

It’s easy to find more examples.

I count seven instances where you either dodged or ignored this correction. Note that above you said, “The problem first is the truth and the facts, not what people think they are.”


HornSpiel - #68492

March 13th 2012

Several things in your response #68483 I find confusing. 


It was never scientifically verified You say this is true first of Newtonian gravity then of NS. I really don’t see how you can say that. Newtonian gravity was refined by Eisenstein but it is still valid for most purposes. Or, if Newtons gravity was not scientifically verified because it could not account for certain phenomenon, Eisenstein’s theory is too not verified—it cannot account for phenomenon at the quantum level. 

You say “Darwin developed his Theory of Evolution based  on Variation and Natural Selection....but the mechanism of Malthusian conflict Natural Selection has never been scientifically verified.” By that you mean the struggle between individuals based on limited resources and a large birthrate. This is of course only one type of natural selection. Modern understandings allow for other factors that just food supply to effect differential reproductive success. However I do not see why you say competition for limited food supply has not been demonstrated scientifically. Don’t petri dish cultures of bacteria demonstrate that every day in medical labs around the world?

Also you claim, it seems, that “modern ecology” has answered questions NS has not been able to. So by this are we to assume that modern ecology has been scientifically verified more rigorously than NS? By modern ecology I take it you mean organisms living in a system where all benefit from the survival of all.Yet aren’t these systems the result of NS in a stable environment? Is there another mechanism or factor you feel science has overlooked?


Roger A. Sawtelle - #68495

March 13th 2012

HornSpiel,

I see that you are confused.  Please note there are two aspects of these theories which are separate.  For gravity they are the equations and the model of reality behind these equations.  Newtonian model of gravity as attraction at a distance has never been scientifically verified. 

Maybe if gravitrons were discovered they would document it, but they have never been found nor ether which was supposed to be part of his theory.  On the other hand it is my understanding that it has been verified that a beam of light is bent by passing through the gravity field of a star.  Thus the model of gravity bending time and space has been scientifically verified.

You should be aware that Thomas S. Kuhn wrote the book The Structure of Scientific Revolutions concerning this very thing.  While some people, like Dawkins, do not agree with Kuhn’s thesis, I think most do and certainly I do. 

With evolution the wo things are Variation and Natural Selection.  Again Variation with the advent of genetics has been clearly been verified.  Now symbiogensesis strengthens the variation side and how variation leads to changer is clear, but the Natural Selection aspect has not been verified. 

Darwin’s model for NS, Malthusian population theory, has not stood the test of time and survival of the fittest has not been proven and has been rejected.  The natural selection that has been verified indicates speciation is closely related to ecological change and the ability of sold and new species to adapt to ecological niches. 

Thus long ago when an astroid strike brought severe climate change that caused the ecology of the earth to change and the habitant of the dinosaurs to disappear, new species of mammals began to appear to take their place in the food chain.  Natural selection did not cause the dinosaurs to fade out because they could not compete with mammals, but because their ecological niches disappeared.

For pity’s sake.  If you want to know more, read my book.      

      

 

 


beaglelady - #68499

March 13th 2012

“Darwin’s model for NS, Malthusian population theory, has not stood the
test of time and survival of the fittest has not been proven and has
been rejected.”


Rejected by whom, besides you and creationists?

“For pity’s sake.  If you want to know more, read my book.” 

It’s always about peddling your book, isn’t it?


Steven Curry - #68500

March 13th 2012

I just realized: the book is why Roger is so entrenched. He wrote a whole book based upon a misunderstanding of the modern synthesis. That’s why he won’t acknowledge a simple, straightforward correction (he has dodged it eight times now). I did find his behavior curious, but now I see the explanation.


HornSpiel - #68503

March 13th 2012

Roger,


I think that Kuhn made some pretty good points about paradigms and how they channel people’s (not just scientist’s) thinking. Kind of put blinders on them to other possibilities for understanding. For that reason I try to keep an open mind about alternate ways of thinking about subjects like evolution, theology and philosophy. 

Maybe if gravitrons were discovered they would document [the Newtonian model of gravity], but they have never been found nor ether [aether] which was supposed to be part of his theory.  On the other hand it is my understanding that it has been verified that a beam of light is bent by passing through the gravity field of a star.  Thus the model of gravity bending time and space has been scientifically verified. 

Now if the above is an example of what you call scientific verification, I am afraid you have lost my interest. I thought that perhaps you had discovered the Northwest Passage, but I’m afraid you are paddling up a dead end slough. I think you would be wise to turn around and go back to the main channel. Still the world of ideas does sometimes benefit from adventurers like yourself…

I am sorry if my questions may have bothered you. I learn better in discussion and find it more enjoyable that reading books so I do appreciate your responsiveness. I must for my part, end the dialog here.

I have determined to refrain from commenting on your posts except for when I see something I really agree with.

Yours,
Kent Spielmann (aka HornSpiel)

btw I also appreciate your lack of anonymity. I am considering reregisterng under my real name. I’d rather like to think I don’t need to hide anything.

Roger A. Sawtelle - #68505

March 14th 2012

Kent,

Thank you for your questions and discussion.

Discussion is good, but books are good too.  Some issues require books where you can have an uninterupted flow of information, so the reader can move back and forth at his or her own time and needs. One medium does not fit all ideas equally well.

I apologize for losing patience with you, but I get upset when it seems that people are taking advantage of me by having me explain everything in detail that is available in a more comprehensive and better documented form my book.

People like me write books to communicate something that they know is important.  If other people agree that this is issue is important, it makes sense that they would buy the book.  We don’t expect people to give away what they worked hard to produce, but of course I have given away many books, so money is not the issue. 

Communication is the issue and these ideas cannot be communicated in “sound bites,” but require systematic exposition. 

 


beaglelady - #68507

March 14th 2012

“Discussion is good, but books are good too.

Actually factual information is good.

“I apologize for losing patience with you, but I get upset when it seems
that people are taking advantage of me by having me explain everything
in detail that is available in a more comprehensive and better
documented form my book.


Nobody is forcing you or anyone else to post here.  You are the one who gets to decide how much to post. 


Roger A. Sawtelle - #68509

March 14th 2012

BL wrote:

Nobody is forcing you or anyone else to post here.  You are the one who gets to decide how much to post.

You are right and I was explaining the pros and cons of posting.  I hope that you do not thank that holding an opinion on this question is for some reason wrong.   

Actually factual information is good.

By the way you have not given us any factual information to verify your view that Natural Selection is based on conflict after Dennis has verified that it is based on symbiosis. You asked me to listen and learn, and I am suggesting that you need to take your own advice.


beaglelady - #68510

March 14th 2012

Haven’t we been over this a thousand times already? I’m beginning to think you’re a bot.


Roger A. Sawtelle - #68514

March 14th 2012

My dear lady,

If you don’t want to discuss it with me, then don’t interject when I discuss it with Dennis or Kent or whomever wants to discuss Natural Selection. 


beaglelady - #68515

March 14th 2012

Steven Curry wanted to discuss things with you and you dodged his questions.


Roger A. Sawtelle - #68517

March 14th 2012

My dear lady,

I am frankly amazed that you are taking Steven’s “side” against me.  You need to do some research before you make charge like this.

If you had done your homework you would have found that I did engage Steven in a long and detailed dialog.  What I found was that he had a peculiar habit of refering me to studies that did not support the argument he was making and he refused to accept the facts that his references presented.

For some reason now he wants me to say that Richard Dawkins agrees with MY view of Natural Selection when he does not.  I did respond in general to his first example and expressed by reasons for disagreeing with his view.

Now Steven is stalking me and demanding that I respond to a laundry list of quotations from Dawkins.  I have made my position clear.  If he does not like it, too bad.  No one has to answer redundant, meaningless questions just because some one asks them.   


Steven Curry - #68526

March 14th 2012

Roger, this site is not a soapbox for you to sell your book, nor is it a soapbox for you to slander those who have exposed the mistakes upon which your book is based.


Roger A. Sawtelle - #68528

March 15th 2012

Steven,

You have gone too far.  First you have stalked me because I refused to agree with your pathetic reasoning.

Now you have accused me of slander in a public forum.  I trust that you understand that you have attacked my character and called me a crook.  

Since you cannot back that up in court that makes you a slanderer using BioLogos as the “soapbox” for your criminal activity.   


Steven Curry - #68530

March 15th 2012

Roger, if you wish to rebut anything I have said then do so. Launching personal attacks against me—especially false ones—is not a substitute for that. I repeat: stop making personal attacks.


beaglelady - #68535

March 15th 2012

“You have gone too far.  First you have stalked me because I refused to agree with your pathetic reasoning.”

He’s not stalking you. He simply wants to follow up on some things you said.

“Now you have accused me of slander in a public forum.  I trust that you understand that you have attacked my character and called me a crook. ”

No, he hasn’t accused you of slander or called you a crook.

“Since you cannot back that up in court that makes you a slanderer using BioLogos as the “soapbox” for your criminal activity.”   

But he has not done anything criminal.



Roger A. Sawtelle - #68536

March 15th 2012

BL,

He simply wants to follow up on some things you said.

And I said No and the reason why the discussion was over.  Stalkers cannot take NO for an answer.  Case Closed.

He said I was using the Forum to slander others, presumably himself.  Slander is a criminal offense, but unless you can back it up with facts, calling a person a slanderer is slander and a criminal offense.  That is just what he has done.

Wake up and smell the coffee. 


Roger A. Sawtelle - #68463

March 11th 2012

Steve, Mike, and H.S.,

Please do not confuse two similar things, symbiosis and symbiogensis. 

Symbiosis is the most basic concept and it is the view that I advocate as the basis of Natural Selection to replace Malthusian coflict theory.  The best know examples of symbiosis are the pilot fish what help sharks navigate the seas despite poor eyesight and the little birds which live on the backs of rhinos.  Both illustrate how very different creatures help one another by creating a ecological niche for themselves.

Symbiosis results in adaption to the environment which includes other life forms.  In this sense the lion and the lioness has a ymbiotic realtionship the the zebra and other its prey.  The lions depend upon the zebra for food.  The zebras depend upon the lions to cull the herd so there is no overgrazing.  Both are dependent upon the climate to provide a good crop of grass so both can flourish.  Dawkins is wrong to indicate that lions and zebras are in direct conflict for survival. 

We are all familiar with the cycle of plants, herbivores, predatores, predators of predatores, scavengers, and natural fertilization by organic wastes.  At all these levels symbiosis is at work and natural selection. 

Dennis says that natural selection today is based on adaption for me that means symbiosis, which is the way natural works to bring all its parts into harmony.  Of course this is an ongoing process that climate chang is making very difficult, so we have more violent weather than before.

Symbiogenesis is another process indeed.  It is two life forms coming together to create a third.  Before Margulis’ work the best know of these was the lichen, a combination of algae and bacteria, which produces its own food.  It is now understood, thanks to ecology, that lichens played an absolutely vital role in oxygenating the earth’s atmosphere so oxygen breathing animals like us could evolve. 

Symbiogenesis is a method of variation which does not depend on genetic mutation.  It of course is subject to natural selection to create a new species. 

Symbionts play play a cruical role in life. The human body hosts billions of nonhuman cells that enable us to fight disease, etc.          


Steven Curry - #68465

March 11th 2012

Roger, you first need to acknowledge that you were mistaken about your perception that “Dawkins has clearly and specifically rejected environmental selection”. The above quotes in #68435 and #68439 directly refute that notion. His books are filled with such examples.


Roger A. Sawtelle - #68466

March 12th 2012

Steven,

Did you ever find that quote in Climbing Mt. Improbable? 

That is the most ridiculous peice of nonsense I have ever seen in a book written by someone who is supposed to be an expert in evolution. 

You can parse Dawkins’ words however you wish, but they do not say that the environment guides evolution, which is what environmental selection means.  If he would clearly acknowledge this, it would mean that his monistic, materialistic, ateleological worldview is clearly kaput, gone, dead and buried, as it should be.    

Tell him, if you can, to stop fighting against the Niche Construction Theory if he wants to make his peace with ecology.   


Steven Curry - #68467

March 12th 2012

Let’s take the quote in #68439.

“Hairiness is one of those characteristics that can increase or decrease in evolution again and again. Vestigial hairs, with their associated cellular support structures, lurk in even the barest-seeming skin, ready to evolve into a full coat of thick hair at short notice (or shrink again) should natural selection at any time call them out of retirement. Look at the woolly mammoths and woolly rhinoceroses that rapidly evolved in response to the recent ice ages in Eurasia.” http://books.google.com/books?id=rR9XPnaqvCMC&pg=PA67

Now explain to us why you think these words “do not say that the environment guides evolution”.


Roger A. Sawtelle - #68464

March 11th 2012

HornSpiel wrote:

NS does not fit into the analogy at all since an arcade game has a goal and NS is manifestly ateleological.

While you are right Darwinian NS is ateleological, that is not true of ecological NS that Dennis and I are talking about.  Indeed James Lovelock, the Father of the modern ecological theory, was accused of inventing a theory based on teleology.  This was a serious charge, which he likened to the scientific kiss of death, because evolution and scientism are based on ateleology as theorized by the strange and unproven views of Monod.. 

Lovelock rejected this charge strenuously, but I would definitely accept it, because a Telos of life and nature is necessary to provide meaning and purpose to science.  For Darwin the Telos of life is survival, but this is irrational, because if life is not meaningful and good, it is irrational to choose to live.

For ecology the Telos of life is working for mutual survival and benefits.  Sometimes it takes sacrificing one’s own life or welfare for the “higher” good.  The purpose of life in not selfish or self sacrificing, but sharing and helping one another. 

For non-humans the goal is the benefit of the group and life itself.  For humans it is the benefits of one’s self, the group, and life beyond this world.          


beaglelady - #68468

March 12th 2012

<blockquote>Symbiosis results in adaption to the environment which includes other
life forms.  In this sense the lion and the lioness has a ymbiotic
realtionship the the zebra and other its prey.  The lions depend upon
the zebra for food.  The zebras depend upon the lions to cull the herd
so there is no overgrazing.  Both are dependent upon the climate to
provide a good crop of grass so both can flourish.  Dawkins is wrong to
indicate that lions and zebras are in direct conflict for survival. </blockquote>

But lions still try to kill zebras, and zebras try desperately to escape from them.  This is conflict, no matter how you try to make it all nice and harmonious.  Would you be willing to be a zebra with a lioness trying to kill and eat you? How do you think a  mother zebra feels when a lioness kills her foal?  It’s hardly pleasant but it happens, no matter how you try to spin it.


Roger A. Sawtelle - #68469

March 12th 2012

Beagle Lady,

Most people eat meat, which means that animals have to die. No the process is npot pleasant, but that does not mean that humans are in a stuggle for survival with cows. 

Dawkins also says that grass does not want to be eaten or mowed, if you can believe that.  When we harvest vegetables, often the plant dies or is “maimed.”  Plants are different from animals and animals are different from humans. 

Most people unlike Dawkins will accept the loss of a part of their body if it means saving their lives.  Most people will accept the loss of their life or the loss of loved ones if it means protecting their nation or saving the lives of others.

We need all three to make the system work.  It is the system which is basically harmonious (within reason), which we are talking about, even though some aqspects are not pretty. 

It really gets down to the choice to utility or perfection.  No process or system based on limited matter/energy is going to be perfect.  If you want perfection you wouldn’t find it in this universe, which means that in a perfect situation the universe would not exist.  On the other hand if you are interested in a system that does work for the ultimate benefit of all, that is possible under God’s Providence and within God’s Creation.   


beaglelady - #68472

March 12th 2012

My point was that there is still a struggle for survival going on.  It’s conflict. Mosquitoes and ticks try to drink our blood. Tape worms, hook worms, etc. try to live in us and steal our partially-digested food.   Insects and disease ravage our crops and domestic animals.  We don’t want this.   I could go on and on. It’s reality. 

“Most people eat meat, which means that animals have to die. No the
process is npot pleasant, but that does not mean that humans are in a
stuggle for survival with cows.


Cows are domesticated.  Hunter/Gatherers are in a struggle for survival with prey animals.  We’ve driven some animals to extinction.   (btw, I’m a vegan)

“Dawkins also says that grass does not want to be eaten or mowed, if you can believe that.”


Grass doesn’t “want” anything.   Except that it apparently doesn’t want to grow in my yard with 3 dogs.


Roger A. Sawtelle - #68474

March 12th 2012

Beagle Lady wrote:

Hunter/Gatherers are in a struggle for survival with prey animals.

Humans are their own worst enemies.


beaglelady - #68480

March 12th 2012

I would say that not only are hunter/gatherers in a struggle for survival with prey animals, but that humans are in conflict with each other. 


KevinR - #68504

March 14th 2012

The true strength of evolution as a scientific theory for the origin of
whales is this: not that we can prove it, (for no theory is ever proven
in science due to its permanently provisional nature), nor that we have
full access to every bit of data we would like (consider how fragmentary
the fossil record is, for example), but rather that we haven’t been
able to disprove it yet, despite our best efforts. Descent with
modification remains a productive educated guess that grows stronger
with each investigation.

I guess we’ll only find out the absolute truth when the time for renewal comes. In the meantime God’s word makes it amply clear that He created everything in six normal days - thereby precluding any fishy evolutionary story. It’s as plain and simple as that.

By the way - those artistic drawings at the top of the article are an example of how images are used to spread the story of evolution - it’s all an illusion.


Steven Curry - #68549

March 16th 2012

Roger Sawtelle,

Your recent responses raise more questions.

You continue to claim that “Dawkins has clearly and specifically rejected environmental selection”. However environmental selection has always been part of evolution. Dawkins is a supporter of standard evolutionary theory, not an opponent of it. For example,

“Hairiness is one of those characteristics that can increase or decrease in evolution again and again. Vestigial hairs, with their associated cellular support structures, lurk in even the barest-seeming skin, ready to evolve into a full coat of thick hair at short notice (or shrink again) should natural selection at any time call them out of retirement. Look at the woolly mammoths and woolly rhinoceroses that rapidly evolved in response to the recent ice ages in Eurasia.” http://books.google.com/books?id=rR9XPnaqvCMC&pg=PA67

Indeed his books contain many examples of organisms adapting to ecological niches.

The above quote appears to disprove your idea that “Dawkins has clearly and specifically rejected environmental selection”. However you have asserted that the quote “does not say that the environment guides evolution”, that it raises a “meaningless question”, and that it shows “pathetic reasoning” on my part. It behooves you to explain these statements.

(In light of your previous comments, I would remind you that your response should not involve personal attacks.)


beaglelady - #68564

March 17th 2012

Well, you are still a criminal, but I’ll overlook that fact if you’ll read my book.


Roger A. Sawtelle - #68565

March 17th 2012

BL,

I am glad you have a sense of humor.


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