Evolution and the Environment
- What real time evidence is there to illustrate the mechanics of evolution based on recent (present day) observations?
- Is the environment a stimulus driving a form of evolutionary change?
- Might the potential for outward changes already be contained in an array of information stored within the DNA of each species? [This suggests most or all change arises without the need for random mutations (i.e., typically the assumed source for infusion of new information) and long-term multi-step evolutionary changes, yet change comes relatively quickly in response to outside stimuli of various types]
- What kinds of examples do we hear about concerning the genetics of adaptation that suggest there is still more to consider ... that is, more than the standard story so often stated concerning how evolution works?
Evolution is commonly explained in terms of random changes leading to adaptations ... and in turn survival of a species ... but what if evolution is nonrandom and change is based on information already in each species-specific genetic code ... and what if nonrandom evolution was truly observable within a human lifetime... yet this research were to find no new species developing ... what then of evolution?
The answer is then ... we are observing microevolution, not Darwinian macroevolution.
The environment can serve as a significant stimulus for change in expression of an already existent genetic code.
In other words, the genetic code may lack little or lack no information such that sufficient information is already available to produce the observed response (to any stimulus) ... as applied to any particular species group.
If the information is already there, randomness need not apply.
There is a 'complete repository' of information held within a cell's nucleus. Science has yet to fully understand what is there in total. So, what may be counterintuitive — and what many scientists might at first reject out of hand — is the suggestion that a complete and fully flexible information base is already present within each species. Such a base exceeds any current need or present genetic expression.
One assumption is that this information base is the result of a random process and building up a genetic library over time. Elsewhere we address the difficulty in making such an assumption. There is no probable means to currently support this. But, how this information may have been installed at some earlier point is not our present focus, yet it's an important question to keep in mind! Why? Because we are looking at change or adaptation from this point onward. Is the next change to arise really evolution in the classical sense?
Examples commonly used to illustrate evolution can be viewed in another light to reveal the point we are making here. For example, when we hear about bacteria that become resistant to antibiotics, insects becoming resistant to pesticides, or finches on the Galapagos Islands changing in response to environmental and ecological conditions (e.g., changes in climate and food supplies) we are told this is evolution in action. And yet all such examples are responses to something in the species' environment. And the change exhibited over an initial period of time may later be reversed when the environment changes again. We are talking about change over brief time spans (e.g., months, year to year, which fits the definition of what is called microevolution) and not alteration as a species morphologically and physiologically changes into a very different and new taxonomic life form (that is, macroevolution or what is commonly labeled evolution).
In the latter case we anticipate a markedly different change in information becomes necessary to change an organism into something entirely new. The role of the environment is perhaps more important in driving the micro-evolutionary changes than what science reports reveal. But on further examination, such a form of evolution is not to be confused with macroevolution— a concept that still begs clear evidence to support itself as the workable or only form of evolution. If you like, you may hold hope for proof of macroevolution, but in fact we have reason to move all current examples into the microevolution column. And here the environment can be seen as a driver that draws on information that already exists within a species ... it has to be there already. There is too little time for new information to come by chance to support the level of change expressed in many of the examples given by evolution scientists.
While all this may seem totally impossible according to the standard story, the concept considered here is an environmentally driven form of nonrandom variation (what you might call: 'nonrandom evolution'). This is something that appears to be demonstrated by the data scientists keep collecting. Yet even the newest data are commonly presented in the mold of the standard Darwinian story. If examined critically, there is another explanation that fits. Nonrandom variations in response to environmental stimuli ... and not random mutations ... are driving expression and change in species.
Yes, changes in genetic codes can be induced in a laboratory (e.g., by radiation, chemical, or other experimental treatment). But consider the results of such impressive cases. Experiments resulting in alterations or a 'rearrangement' of existing information within a code commonly produce either non-adaptive or lethal results. This is not a process causing new information. Elsewhere, genetic engineering directed by humans commonly moves information around by an intelligent cause and not chance.
Yes, there may be great potential for information resources already stored within organisms such that no new information (or very little) need be created. The environment sparks changes such that species show relatively rapid change based on existing information found in the DNA. Furthermore, many of the known examples of adaptive change may be the result of a loss of specificity. That is, information is lost, not gained.
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Consider This :
The following discussion highlights ideas initiated by the writings of Dr. Lee Spetner. First, we will not give an entire account of Dr. Spetner's discussion. For the content and context in complete form, we recommend you read his book (Not by Chance). Second, his writing is not based on one source alone ... Dr. Spetner illustrates many examples from other sources in the scientific literature.
The important concept here is the way information in an organism is used to adapt to changes in the environment. The environment is the stimulus and the response must be relatively quick or the species is at risk ... ultimately it all comes down to the survival of a species. Spetner revisits a proposal that precedes his thinking on this topic ... a proposal concerning a form of 'evolution' that's largely ignored. But information (scientific data) gathered over time provides good reason for a closer look:
... The increasing amount of data, accompanied by their increasing reliability and quantification, compels us now to give serious consideration to this proposal. Spetner (NBC) Page viii
In the seventh chapter, I suggest how there could be evolution without randomness. The main idea is that the capacity to adapt to a variety of environments is built into the organism. The environment induces the expression of this capacity. Spetner (NBC) Page xi
It's not just that organisms can adapt to environmental changes, but that the response is nonrandom—not simply a proposition of chance evolution. Dr. Spetner is just pointing to an information base that already resides within the organism. That is, this is information is induced to appear but is not a further invention of new information resulting from an evolution process.
Genes that were once useful but aren't now, could still sit in a the population. The more there are, the longer they can stay dormant in the population. Some genes would be adaptive now if they could get put together right. They may need only a recombination or an inversion to reawaken them. And others could be in the population in working order, but would not be adaptive now. They could lurk there, hardly noticed, until they are needed once more. Spetner (NBC) Page 65
There are a couple of key terms used above. Dr. Spetner's book is like many texts that define terms such as recombination or inversion, which are terms describing how existing portions of the genetic code are moved around [within chromosomes of a cell]. This is not production of new information but here it's the expression of information that is changed. The concept of a species building new information over extensive time periods is addressed by another feature article examining probabilities. If long term evolutionary change is improbable, then we must ask: What in fact is happening when humans observe shorter term evolutionary change? And here we can begin to differentiate what one can observe as opposed to what is often assumed about evolution in general.
The Best Approach Might Really Be Nonrandom Variation
When evolutionists say genetic variation is random they mean to say the chance of a variation occurring has nothing to do with the way the variation helps the organism adapt to its environment. When I say a variation is not random, I mean that the chance of it occurring has something to do with how the organism adapts to its environment. I mean and that the adaptation in some way has been influenced by the environment or the needs of the organism. Spetner (NBC) Page 175
Speaking of evolutionists who think of 'progress by chance events over time' ... they:
... must hold that, on the average, cumulative selection has to add a little information to the genome at each step. But of all the mutations studied since genetics became a science, not a single one has been found that adds a little information. It is not impossible, in principle, for a mutation to add a little information, but it is improbable. Spetner (NBC) Page 179
is NO small point!
Yet, how often is this taught to high school or college students? If Dr. Spetner is correct, then some other process is at work. That's why he is considering the implications for a nonrandom process.
Remember that the neo-Darwinian theory (NDT) is widely accepted. The NDT foundation is built on the assumption of many small random mutations build over time to make for large evolutionary change. But evidence for this assumption—or what Spetner calls speculation—came after Darwin.
The speculation was never the less accepted as possible, even as fact. But during the half century of the NDT, we have probed the molecular level of cellular functions. Now, as we come to the close of the twentieth century, we have a lot of evidence of the nature of the mutations to which the neo-Darwinians assigned the role of the small variations. None of this evidence vindicates the Darwinian speculation that large-scale evolution has its source in random variation. All evidence is against it. Spetner (NBC) Page 179
There are recent examples of scientists recognizing what the data are telling us about nonrandom variations. So, the variation might be a change in a species after some variable in the environment changes. The genetic change being nonrandom provides for an outwardly observable change (i.e. in phenotype) but the DNA's information (i.e. the genotype) is already there awaiting expression—according to the concept presented here.
But look at the coordination that must take place. For example, a change in environment may alter the available food supply. What if the food source is dramatically changed? The genetic controls in cells must shift to make appropriate enzymes to utilize the new food source. How does the organism respond? How does a daughter generation survive?
Dr. Spetner notes that some genes are turned on or off as needed. Whether on or off, genes in both states reside within the genome. [So, again, the genome is like a place for the information, the genotype is the exact information in that place, be it on or off, and the phenotype is what we 'see' ... that is, the result of the expressed information from that genotype. Not all information in the genotype need be expressed at any one time.]
If the food supply shifts again, alternate genes get turned on. The result is appropriate enzymes are systematically produced or activated as needed. This is a system based change not a random set of variations that eventually hit on the appropriate enzyme. The organism overall maintains life function in spite of the ongoing changes in its environment. This example may work better for bacteria than more complex life forms. But survival can come from within a population that includes some individuals that are already able to absorb the change and also develop offspring to make the next generation. This then provides a strategy for species such as birds that have been observed to change with changes in food sources (that is, in relation to changes in environmental condition)s. The latter example is in fact based on recent research on the Galapagos Islands and the finches Darwin is often associated with! So, nonrandom variations may occur at many levels within the hierarchy of life.
... If the changes are random, the chance of a "right" change occurring is proportional to the fraction of "right" changes among all possible ones. The number of "wrong" changes is vastly greater than the number of "right" ones. But—and here is the important point—if the genome were set up for an adaptive change to be triggered by a cue from the environment, then chance wouldn't be involved. The right adaptive change would be sure to occur when it was needed.
There are several different kinds of variations of the phenotype that can be induced by the environment ... In the first class are variations in the phenotype that result from changes in the DNA sequence. In the second class in the phenotype without a change in the DNA sequence.
The mutations I am calling for are those that show evidence of being nonrandom in that they are triggered by the environment. Spetner (NBC) Page 183
Without repeating all the details and examples that Dr. Spetner gives in Chapter 7 of his book, we can briefly summarize that he makes a case for responses by organisms in conjunction with environmental stimuli. While the origin of the entire information base that is embodied within the organism to begin with is not demonstrated anywhere by science, clearly there is an apparent presence of the information revealed by quick changes in the appearance and function of the organism’s parts (i.e., morphological or biochemical).
Some of the genetic gymnastics that genes use in working the resident information include:
... It can produce deletions, duplications, and translocations. Recombination is not a random process. It is under strict genetic control, and requires several special enzymes for its operation. These are even special genes that affect the efficiency of the recombination [Griffiths et al. 1993 , pp. 571 ff.]. Spetner (NBC) Page 186
You can move information, flip it around, turn it on or off, even delete it ... but only if it already exists.
Dr. Spetner cites examples from the published literature that illustrate how remarkably rapid responses can be. Even in bacterial systems with short generation times, if adaptations were expected to come by chance, a result (response) may take as much as a million years. When experimentation reveals responses in terms of days instead of millennia, we are provoked to consider other perspectives (See example from Hall on salicin metabolism Spetner (NBC) Page 189).
If the results of these experiments indicate that adaptive mutations are stimulated by the environment, they contradict the basic dogma of neo-Darwinism. According to that dogma, mutations are random, and the kind of mutations that occur are independent of the environment. If mutations are really nonrandom in the sense that the environment can stimulate adaptive mutations, and then the paradigm of Darwinian evolution, which has dominated the biological sciences for close to 150 years, must be replaced. In science, a paradigm of such stature cannot be allowed to fall easily. Spetner (NBC) Page 190
Nonrandom response following environmental cues presents an interesting solution to the standard story of change by random selection. In fact, research conducted to clarify the issue in favor of evolutionism has deepened the controversy without eliminating the nonrandom perspective.
Darwinian evolutionists see the nonrandom interpretation of these experimental results as obviously incorrect because they contradict the neo-Darwinian dogma. I, on the other hand, see this interpretation as confirming, on the bacterial level, the nonrandom variation indicated by many examples in plants and animals—examples that Darwinian evolutionists have largely ignored because they do not fit in. Resistance to the nonrandom-variation interpretation stems from a refusal to abandon the Darwinian agenda that evolution must confirm that life arose and developed spontaneously. Spetner (NBC) Page 191
If we insist that Darwinian mechanisms are solely responsible for what we see, then we'll miss nonrandom adaptive variation. If we start to think in terms of environmental signals turning on genes that are already there, then we are expanding on the current view and adding a new perspective. An alternative to the standard thinking is being proposed here. And our WindowView portrayal of this proposal is simply a first look. Also note, Dr. Spetner concedes real answers will ultimately be decided in the laboratory.
As indicated above, nonrandom variations may appear as the changes in phenotype (e.g., changes in bird beak, plumage, length of a mammal's leg or tooth and jaw structure, etc) without a change to the DNA. This raises the issue of inheritance of traits from generation to generation. And Dr. Spetner addresses that issue, too. His explanation covers turning genes on and off and how this relates from generation to generation, for example:
The ON/OFF state is passed from mother to daughter cell as the cells differentiate. Not any method of turning genes ON and OFF lends itself to being passed on through cell division to later cell generations. How cells during development pass on their genetic state to daughter cells is not yet well understood. Spetner (NBC) Page 192
Another important consideration is how nonrandom variations fit within the fossil record.
One can't help wondering how much of the fossil record might be the result of the direct influence of environment on the phenotype without any change in the genotype. We know the form and shape of teeth is strongly influenced by diet. Similarly, the form of bones is strongly influenced by the forces to which they are subjected during growth. Many of the fossils that have made the news as " missing links " consist mostly of teeth. Most of the rest are bones. What kind of support can fossils of bones and teeth, then, give to the randomness postulate of the neo-Darwinian theory? Spetner (NBC) Page 196
And implied in all this is a standing base of information. That's really what a genotype is ... that is like a library all set up with no new books being added ... the library is all there. The phenotype (e.g. certain appearance of some structure) may really change and yet this external change only lends from what is in the library. A change back is also based on information in the library. And as suggested here this interplay is not dependent on random mutation or new information being added. Mutations in fact, as illustrated by Dr. Spetner's examples, may cause a loss and not a gain in the library's information.
John McDonald of the University of Georgia has pointed out the lack of correlation between the sizes to of the phenotypic change and DNA change. Differences in DNA between species seem to be unrelated to their supposed evolutionary divergence [McDonald 1990]. Citing the work of Allan Wilson and his co-workers [Wilson et al. 1974], McDonald noted the differences and similarities between frogs and mammals. There are two frog species, which are very much alike, but differ greatly in their genomes. The mammals, however, which have great differences in phenotype, differ little in genotype. These data indicate that the size of genetic changes may be unrelated to size of phenotypic changes. Indeed, much genetic change may be irrelevant to evolutionary change.
On the other hand, many examples have been reported of the adaptive phenotypic changes triggered by environmental cues. (For starter's see West-Eberhard [1986, 1989], Bradshaw , Harrison , Schlichting , Stearns , and the hundreds of references in these papers.) Spetner (NBC) Page 198
And what if the repository of information in this genetic library shows something else ... like flexible design! An intelligent use of information, resources, and prudent strategy for survival may reveal a dynamic built into the library. The design works within the environmental signals, constraints placed on growth, giving balance sustaining life beyond systems simply turned on ... the genome is more than information for information's sake ... the tip off here is flexibility ... call it plasticity.
An organism's ability to change as the environment changes is known as phenotypic plasticity. It has been widely observed in both plants and animals for more than a century. Spetner (NBC) Page 199
Dr. Spetner uses an example based on plants that appear to vary their seed production based on spacing. A set genetic control might result in constant number of seeds, but the plasticity shows up as less seed production in plants that are closer together. More seeds are produced when (e.g. Linseed) plants have greater space between them. Again, think about the coordination here. A simple 'dumb system' would always produce the same level of seed output. The variation appears linked by design. Perhaps this is related to energetics and feedback systems beyond any one plant alone. We are assuming growth responses aren't entirely limiting in such examples. How does a plant 'know' to regulate seed output? More than hormones or nutrition, there is an information system at work. After all, why waste resources and energy where there is little gain to the individual or species as a whole? Further, there is an optimizing the number of seeds required to further colonize the area that remains between mature plants. The plasticity implies more is at work that simply ending a life cycle with seed production.
Dr. Spetner is stepping out with some suggestions:
I am suggesting here that organisms have a built-in capability of adapting to their environment. I am suggesting that to the extent that evolution occurs, it occurs at the level of the organism. This suggestion differs sharply from the thesis of the NDT, which holds that evolution occurs only at the level of the population. Organisms contain within themselves the information that enables them to develop a phenotype adaptive to a variety of environments. The adaptation can occur by a change in the genome through a genetic change triggered by the environment, or it can occur without any genetic change. Spetner (NBC) Page 200
Consider how an engineer would design organisms to respond to a whole host of environmental changes ... the best approach ...
would be to build into the species the ability to switch among several forms, each highly adapted to one of the environments. He would design the switch to be triggered by a cue from the environment. I am suggesting here that living organisms have the capability of switching from one phenotype to another when cued by the environment.
For the organism to have this capability, it has to have in it the necessary information. No one yet knows how much capability this sort is built into free- living cells, plants, and animals. The more built-in potential there is, the more the information the organism must carry. One would expect the seat of this information to lie in the genome. Can the genome carry all this information? There is a vast amount of DNA in plants and animals whose function is as yet unknown. Could the role of some of this DNA be to encode the potential phenotypic diversity needed to adapt to a variety of environments? Mitochondrial DNA and plastid DNA also may play a role in coding this information. Indeed, both mitochondrial DNA and plastid DNA have been reported to have some effect on the phenotype in plants [Walbot and Cullis 1985]. Spetner (NBC) Page 201
Dr. Spetner provides a discussion of Darwin’s finches from the perspective that new species appear as the result of environmental influences and not the putative forces typically associated with gradual modification and natural selection. Another example based on finches on Laysan Island show rapid change over a very short time frame. [Page 204]
The diversity of the finches on Southeast and North Islands could, however, be explained as a phenotypic phenomena entirely. A change of diet might produce the appropriate bill shape and jaw structure. Alternatively, the environmental effect could have thrown a genetic switch, which would have, in turn, changed the phenotype. In either case, the effect would appear in many individuals. There would be no waiting for a mutation to occur or for natural selection to work. A change to a new species could occur quickly, even in one generation.
These results show that bill size in finches can change from one adaptive type to another with diet. Spetner (NBC) Page 205
A New Hypothesis: The NonRandom Evolution Hypothesis
We are giving a lot of attention to Dr. Spetner's ideas to make a simple point on perspectives. Right or wrong, different thinking is commonly excused by the main stream. If inn this case Dr. Spetner is correct, then the course of the main stream is misdirected. To alter the stream course is an enormous task. In all that is noted above we are brought to a proposal—an alternative hypothesis—which is put forth for our consideration:
The NREH is a hypothesis that explains many observed phenomena that the NDT does not explain. According to the NREH, adaptive modifications in organisms occur when the environment induced is a change in either the phenotype or the genotype. It can account for the environmentally induced adaptive mutations reported in bacteria. It can account for the pervasive convergences found throughout the plant and animal kingdoms. The NREH does not suffer from contradictions of the NDT, and promises therefore to provide a more consistent picture of life. Spetner (NBC) Page 208
Quotations from "Not By Chance" (NBC) written by L. Spetner, are used by permission granted by Dr. Lee Spetner.
Writer / Editor: Dr. T. Peterson, Director, WindowView.org
Excerpts and links to Feature Articles:
''Every student of biological evolution learns about peppered moths. During the Industrial Revolution, dark ("melanic") forms of this moth, Biston betularia, became much more common than light ("typical") forms, though the proportion of melanics declined after the passage of pollution-control legislation. When experiments in the 1950s pointed to cryptic coloration and differential bird predation as its cause, "industrial melanism" became the classical story of evolution by natural selection. Subsequent research, however, has revealed major flaws in the classical story. It's time to take another look.'' MORE on this, read: Dr. Jonathan Wells on Evolution's Example Based on the Peppered Moth
Related Link:Bookmarks - Questions about the ICONs of Evolution
(examples from Dr. Wells!)