Posted on 03/09/2009 5:51:51 PM PDT by betty boop
Microevolution, Macroevolution; Chance, Necessity
by Jean F. Drew
A friend asked me the other day, “What’s your understanding of the mechanism that causes microevolution, and how would that mechanism differ in the case of macroevolution?”
The question struck me as loaded. So I thought it might be good to unpack its elements, beginning with an analysis of the terms microevolution and macroevolution.
As Doron Aurbach, Professor of Chemistry at Bar Han University, Israel, has pointed out, “When we examine what is universally known as evolution theory, we need to distinguish between two distinct aspects of the theory, namely, micro- and macro-evolution.”
Microevolution
Micro-evolution is a reality that is experienced in life and documented by reliable scientific experiments and observations…. It includes observation of speciation in some kinds of birds and insects, due to the interrelationship between genetics, environment, and adaptation. In fact, the genetic code of all living species allows for certain degrees of freedom and change for any property that is inherent in these species. These degrees of freedom are in part intrinsic, that is, they are part of the genetic code itself, and may be caused by mutations, or, in layman’s terms, by sporadic and occasional changes in the genetic code. This freedom of the genetic code is of critical importance because it allows for the adaptation of life to environmental changes and for all the wonderful diversity that is seen in life on earth, enabling human beings, for example, to be distinguished from one another, by appearance, as well as by unique identities and characteristics. This adaptive ability of genetic codes … is nothing more than a fine tuning of basic properties. ["Intelligent Design vs. Evolution Theory," Divine Action and Natural Selection, Singapore: World Scientific, 2009, p. 687]
Macroevolution
In contrast to the micro-evolutionary approach, there is the macro-evolutionary philosophy, which proposes that everything that we see around us — reality, life, and faith — is accidental and could simply have occurred naturally. This approach asserts that, for some reason, matter starts to live by spontaneous and possibly inevitable processes. Thus, “living” molecular clusters crystallize into living cells, after which these primitive cells develop internal, well-defined organs (e.g., the so-called prokaryotes–eukaryotes transformation). Single cells then spontaneously join together to form primitive multi-cell creatures, which continue to develop — again, spontaneously — into increasingly more complex entities. The various cells in these primitive multi-cell communities then develop specific functionalities over the years and become true organs. Thus, as macro-evolution posits, over a period of millions of years, creatures have gradually developed to possess functional systems that we recognize today as the various organs of living species. The magic words — ‘selection rules.’ The environment is thus acknowledged as a dynamic force that causes adaptation and improvement of the species, with better functions persisting and the worst functions or responses to the environment disappearing.
In brief, this is the essence of macro-evolutionary philosophy — the evolution of matter into a living, breathing human being. To put it differently, the mere existence of water, the earth’s elements, and a flux of energy from geo-thermal sources and radiation from the sun leads inexorably to the creation and development of life, from primitive to complex forms. [ibid., p. 688]
Notice that Aurbach calls macro-evolution a “philosophy.” He thinks it’s “nothing more than a belief — and a fanatic belief at that — in accidents and in the power of serial, random occasions to bring matter to life.”
Now that’s one man’s opinion — but many intelligent people have drawn pretty much the same conclusion (evidently including not a few working chemists). Yet even if a person disagrees with this opinion, it should be fairly obvious that there’s a good deal of difference between the micro- and macro- models of evolution.
In the first place, micro-evolution pertains to adaptations within species. Macro-evolution (which is what we normally associate with Darwin’s original theory) pertains to the manner in which one species changes into another species. Obviously, these are not the same things.
And so it’s not immediately evident how to find a “common mechanism” between them. For one thing, micro-evolution is “testable in the lab”; macro-evolution is not. Further, no one anywhere has ever directly observed one species turning into another — and direct observation is a fundamental requirement of the scientific method.
In short, macro-evolution does not tell us how one species turns into another, but only that they do. This expectation is not the product of direct observation (nor with reference to past events, can it ever be); it is an inference largely based on the fossil record which, all protest to the contrary, is still spotty and inconclusive.
There is the further difficulty that a scientific theory must have predictive value. That is to say, it has to “forevision” an event that has not yet taken place, but can be expected to take place on the basis of the theory. The type of event we’re dealing with here is a speciation event — which in the original Darwin theory is the transformation of one species to another.
Question: Has there ever been even one successful prediction of a speciation event that has been subsequently observed and validated on the basis of the requirements of the currently reigning scientific method that goes by the name of methodological naturalism?
My answer pithily put: I’m not aware of any. The fact is, I don’t see any prediction of macroevolution theory that could be tested (falsified) on the basis of replicable experiment. I strongly doubt it makes any predictions at all that could be of interest to science, as science.
But it does make for an interesting “philosophy.”
My own view, for what it’s worth, is that there is massive evidence for evolution per se — of nature, of life, indeed of the universe itself. Even theologians are not averse to this understanding. For example, two Popes in a row now — John Paul II and Benedict XVI — concur that evolution happens. But they draw a reservation that goes straight to the heart of classical Darwinian theory: Because evolution happens does not mean that it is a wholly random, purposeless process. Bottom line, evolution is about change in nature, the precise mechanisms of which are still not fully understood, and most likely cannot be fully understood on the basis of a materialist, mechanistic model that makes purposeless, chance, blind accidents the source of the (patently obvious) order of the natural world; the origin of life; and its speciation over time. This suggests to me that neither Karol Wojtyla nor Joseph Ratzinger (two world-class philosophers and academics, might I add) regards Darwin’s original macro theory as the last word on the matter.
Jerome Yehuda Gellman, professor of philosophy, Ben-Gurion University of the Negev, Israel [op. cit., “God and Chance,” p. 450], describes modern-day evolution theory as “an exciting convergence of paleontology, embryology, geo-biology, genetics, cell biology, geology, and anatomy.” Crudely put, it seems the biggest action in the understanding of evolution is coming via the disciplines of genetics and information theory; and so the predominant focus nowadays seems to be the mechanisms of micro-evolution.
Darwin, of course, had no idea that such disciplines were coming when he published Origin of Species back in 1859. (Another reason I hesitate to draw a link between micro- and macro-evolution: At the time of its devising, macro-evolution did not take the science of genetics into account; Mendel’s ground-breaking work was unknown to Darwin, let alone the scientific revolution that was kicked off by Watson and Crick in the 1950s.)
Chance and Necessity
If there is to be a “reconciliation” of micro- and macro-evolution, it seems to me it must come from an understanding of chance and necessity, and how they “synergize” in natural systems.
Macroevolutionists tend to put all their stock in “chance.” Nobel Laureate in Biology Jacques Monod put it this way: “Chance alone is the source of every innovation, of all creation in the biosphere. Pure chance, absolutely free but blind, is at the very root of the stupendous edifice of evolution. The central concept of biology … is today the sole conceivable hypothesis, the only one compatible with observed and tested fact. All forms of life are the product of chance.” [Chance and Necessity, 1971]
Thus pure blind chance is the input, and natural selection "selects" the output. The result: a “fit” specimen, “fitness” defined by the organism’s ability to successfully reproduce itself. So even though Nature did not intend this “fitness” result (because she is by definition “purposeless,” and so cannot intend anything), “fitness” is the non-purposive (i.e., unintended) result of evolution.
I do not see, however, any way for random accidents to simply pile up indefinitely until they finally, and quite “blindly,” produce ordered, functional, "fit" biological systems in nature. Not only is this counterintuitive; but it flies in the face of direct observation of natural systems conducted by countless human beings over millennia.
On the other hand, if random events occur in a guided system, they can eventuate as contributors to functional biology.
But to understand this, we have to introduce the ideas of holism and hierarchy in biology, which entail that “chance events at the micro level of a living organism need not entail chance events at the macro level.” [Gellman, op. cit., p. 456]
What is determined for a macro-level need not be determined at a molecular level. [Note that activity at the molecular level — because it possesses certain “degrees of freedom” — is not perfectly “predictable”; i.e., it is “random” in that sense.] And so Gellman observes that
The idea is that occurrences at a lower [i.e., microscopic] level can occur by chance, relative to what is determined at higher [i.e., macroscopic] levels, but occur within the boundaries allowed for by the higher structures, and then are funneled along a causal path by, as it were, the curvatures of the higher grid. Holistic systems occur outside biology as well, as, for example, radioactive decay, where it is precisely determined how much material over-all will decay, whereas which atoms in the material will decay is purely random. [ibid., p. 457]
Yet, as Gellman notes, “the application of this idea [i.e., holism] is quite controversial in biology.” (Probably because it raises the spectre of “intelligent design” in many minds nowadays.)
What Gellman is getting down to, it seems, is such “macro” grid structures “impose direction upon micro events [which are themselves] undetermined by the grid.”
Thus we obtain a glimpse of the complicated, dynamic relations that obtain between chance and necessity.
So, how to think of “chance” and “necessity?” How to understand what they are, and their putative relations?
Gellman offers a clue, but it is one that perhaps only Christians and Jews will grasp immediately (let alone would be prepared to accept). His suggestion is that “necessity” refers to divine Providence; “chance” refers to the source of novelty and variety in Nature, especially biological nature.
Think of God, then, acting as the highest-level [i.e., in the “hierarchical”] framework in which individual events occur. Then, individual occurrences within the framework can occur by chance, within the boundaries allowed for by the framework’s structure, and then be funneled along a causal path by the “curvatures” of the grid. In that way, micro-chance is consistent with macro-Providence, where the providence will be systemic and natural, rather than [directly] intrusive into the natural order.” [ibid., p. 457]
For certainly, to the religious mind, “necessity” is given by God. It never changes; for it is the Logos of the universe. But if all in Nature were fully, completely determined by this necessity, nothing would ever change in Nature: It would be perfectly static. That is why there have to be “random” events to express and facilitate God's own plan for His creation. For all of life is joined to everything else in the universe, and thus pragmatically speaking, every event that occurs in Nature is necessarily “contingent” on the outcomes of unforeseen “accidents.” And yet all events are ultimately "purposeful" — for God's creation is finally purposeful. God, in short, is not prohibited from using "accidents" to accomplish His purposes.
The point is, no pile up of pure “accidents” in an unguided system is bound to realize either systemic order or function. Such a system is capable of producing only more accidents.
Which is why I think the great pre-Socratic philosopher Heraclitus and, much later, the great German mathematician-philosopher Leibniz were both exactly right to say that the changeless and the changeable are the two basic constituents of life and the cosmos itself. They both said the same thing: All of Nature is the product of a dynamic tension between that which does not change, and that which is capable of changing.
And Leibniz also raised two profound questions which, I think and believe, can only find answers if we allow the idea of “that which does not change” into our thinking. They are: (1) Why are things the way they are, why not some other way? (2) Why is there anything at all, why not nothing?
Or as Plato would put it, there is a universal, ineluctable dynamic tension between changeless being and changeable becoming — and that’s what makes a universe, especially one that has been “primed” for Life from the get-go.
If the biological sciences want to elucidate what life is, how it arose, and how it evolves, it seems to me that such problems of changeless–changeable cannot continue to be neglected.
The problem is, “random” and “changeless” seem to be mutually-exclusive terms. How can they possibly “interrelate” in synergy?
Still it seems to me that the manner in which they interact has a whole lot to tell us about biology. So it seems to me folks would do well to look at the problem from this aspect.
©2009 Jean F. Drew
[Any ancillary rights under the “Fair Use” doctrine respected provided proper citation of the source is given.]
It all must be true because the religion of humanism, with daily services in the church of darwin, simply require it, and require all to believe OR ELSE.
Just a FYI on what I hope will result in an interesting discussion! Hope you’re free to participate!
read later
As long as one does not try to make God the unmoved mover of Aristotle. Creation is not the same thing as cause.
didn't happen
won't happen
regardless of what the church of Darwin spouts.
That's why we call the laws of thermodynamics "laws" and not "really good ideas for every part of the known universe except the religious pet theory of evolution".
Do these godless world-view postings get old to anyone else?
evos..go ahead an reply to my post, but I will not reply.
... read my tag line...that is my reply!
Good article!
The idea that because microevolution can be seen to occur, therefore given enough time and chance and whatever else macroevolution can occur is just extrapolation.
Extrapolating is not the scientific method.
I’ve seen different definitions of micro-evolution but like this one because it allows for speciation. Many argue that micro-evolution cannot cause speciation, but I think that notion is too limited.
I reject abiogenesis and the bigger leaps made by current evolutionary theory. Not for religious reasons, but for scientific reasons. God created all sorts of natural laws and I have no problem with evolution being one of those laws.
A biologist can look at a light-sensitive spot on a bacterium and claim that they were obviously the predecessor to human eyeballs. A biochemist can look at the chemistry behind both and conclude that the biologist made an unreasonable logical leap. Animals simply don’t have huge numbers of chemicals in their bodies waiting around to evolve into something.
bttt
Science involves ascribing natural and measurable causes to natural phenomena.
This “micro” “macro” garbage is like saying that the observed “micro” erosion is not sufficient to explain “macro” geographic features.
Micro continental drift isn't sufficient to explain why Antarctica has temperate dinosaurs buried under the ice but no modern species.
Nowhere is there a mechanism that would stop “micro” evolution from accumulation into the “macro” evolution we see in species related by common descent.
What is going to stop a 2% genetic difference and a 6% genomic difference from accumulating between humans and chimps over some seven million years of divergent evolution?
Depends, I guess, on how ones defines "cause."
Some people see creation as a one-time start-up event. Of these, some say that the singularity of the Big Bang (the putative inception event) contained in itself all the causal factors of Nature, such as space and time, the constitution of matter itself, the physical and chemical laws, the language of mathematics, etc. — an event so substantial, so comprehensive in seed, that it is the cause of everything else that ever followed from it in space-time reality.
It is quite possible to see creation as an original discrete event that occurred once, and then was pretty much "done." Yet others may see it as a continuous universal process that is reflected in the spatio-temporal world as the evolution of Nature.
It seems you're allergic to the idea of a First Cause, which would be the Aristotelian Unmoved Mover.
Yet logically, an Unmoved Mover is required to move a universe into being if it must start from nothing. If the universe had originally been moved from a "something," then an Unmoved Mover would not be necessary.
Which is why a whole lot of folks nowadays find the idea of an "eternal universe" — a universe that is by definition uncaused, something that just always was, from forever to forever — so attractive.
This idea removes the entire idea of ultimate causation in Nature from the table. But if you get rid of that, what would be the sufficient basis for the existence of the physical, i.e., natural laws?
My own personal intellectual and spiritual leading on this question is this: God uses the laws of nature to perfect his creation on a constant — that is to say timeless — basis.
He doesn't have to step in and do every little thing in Nature Himself because His original design for Creation is just simply so amazingly "providential" in every way.
And yet He leaves a role for chance....
Me either, Dallas Mike!
Thank you ever so much for writing, dear brother in Christ!
I agree with you that evolution is a natural law created by God, but animals DO have huge amounts of DNA in their bodies waiting around to evolve at a known and measured rate that is more than enough to explain the different DNA patterns we see in related species.
The Big Bang remains a scientific hypothesis to explain the “view” that we have of the Cosmos. That view changes all the time. Not only what our telescopes tell us but what our microscopes do. Even with our machines we are limited in what we can know, What is amazing is how much we do know. Ironic to me that atheists aspire to god-like powers, even to the point of looking for “saviors” from outer space.
Part of the problem is the original meaning of evolution, to a spiral originating from a point, or to the development of a living being from a seed.
I'm very pleased to see that you have broached micro/macro-evolution and unchangeable/changeable!!!
The only thing I have to bring to the discussion is something I mentioned on an earlier thread.
Namely, that microbiology is a "hard" science like physics and chemistry where the principle of "the absence of evidence is evidence of absence" applies.
Conversely, paleontology is a "historical" science like archeology and anthropology where the principle is the reverse: "the absence of evidence is not evidence of absence."
Therefore I aver that it is an overstatement to project from the lab to the dig.
Or to put it another way, there is no laboratory experiment a microbiologist can perform to falsify an alternative explanation for what the paleontologist observes in his dig.
Alternative explanations would include God creating through evolution, God creating various living creatures with the ability to adapt and or evolve, God creating through evolution and also intervening now and again - and of course, panspermia.
Truly, in the absence of space things cannot exist. And in the absence of time, events cannot occur.
Physical causation requires both space and time.
And we know from cosmic microwave background measurements from the 1960's forward there was a beginning of real space and real time in this universe. Or to put it another way, space/time doesn't pre-exist, it is created as the universe expands.
All physical cosmologies (big bang, multi-verse, multi-world, ekpyrotic, cyclic, imaginary time, etc.) rely on space and time for physical causation.
That is their poison pill. No matter how far back they push it, there is always a beginning of real space and real time.
IOW, there had to be an uncaused cause of space/time and therefore, physical causation itself.
And of course the only possible candidate is God.
Because it hasn't been seen.
Blinded by faith?
No. On the contrary, science is what's blinded by faith by presuming that something they haven't observed can occur by accident when scientists can't even make it happen on purpose..
Assuming macroevolution just because microevolution is observed is speculation. It has not been observed, it has only been deduced.
Genetics indicates that DNA resists change....
Twin Strands Of DNA Seek Each Other Out
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