Neo-Darwinism and the Age of Genetics
Questions:
- Is evolution theory the same today as compared to Darwin's original thinking?
- What has science learned since Darwin to change the view on evolution?
- Is there a totally new view on evolution or is the theory much like Darwin's but reformed by new evidence?
Short Answer:
Darwin, Wallace, Buffon and others, in the 1800s and before, first gathered and refined many concepts on biological evolution. But these thinkers were unable to know how traits (e.g., specific features exhibited by plants and animals) are inherited (i.e., passed along) from one generation to the next. The age of genetics came later. But when it did arrive, the new discoveries were ideologically kept in line with expectations for how evolution works.
Darwinism was updated with new information—to keep much of the standard story intact—yielding what is today called neo-Darwinism. Yet the age of genetics has progressed to an era of molecular research that integrates what science knows of genetics, cellular biochemistry, cell structure, and the immense information requirements for life's function. Neo-Darwinism in the early 20th century was essentially passing the baton in a race where evolution theory was making a good run.
Yet, the molecular research brings still another new era, new evidence, and to a certain extent a silence on how the data work with or against evolution. The molecular data is not clearly nor fully further evidence in favor of evolution—that is neo-Darwinism in the race of new evidence is losing its grip on the baton. As described elsewhere, evidence for design, the intriguing puzzle yielding life's irreducible complexity at the molecular level of life, the loss of specificity (e.g., of enzyme function) through seemingly advantageous mutations, and the role the environment plays in directing change in species are some of the examples that go beyond the assumptions housed by neo-Darwinism.
In brief, we'll make note here of what the transition point is between Darwin's original thinking and the neo-Darwinian synthesis by scientists in the early 20th century. Science huddled up to make a new game plan and carried Darwinism further into the latter 20th century with some reforms to the original theory. Genetics in its infancy provided one of the stepping stones leading to the neo-Darwinian movement.
Consider This:
Interestingly enough, there was an overlap between Darwin an Austrian monk who could have delivered powerful insight to where the evolution theory was headed. Had Darwin heard of or met Gregor Mendel (1822-1884) we might see a different story today.
While he was teaching he began, in 1856, to experiment with plants in the small monastery garden. He spent his time in the garden studying what happened when he crossbred peas. After he became abbot, he no longer had the time to pursue his science, but he retained a strong interest in it for the rest of his life. In 1865 he published his important discovery that would in time give the support that Darwin's theory so badly needed.
Mendel found that inherited traits do not get mixed and diluted.
Darwin never knew of Mendel or his work; Mendel published his work in an obscure journal. The scientific community discovered his work only in 1900, eighteen years after Darwin died, when a Dutch botanist, Hugo de Vries (1848-1935), brought it to their attention. De Vries took an interest in Mendel's results, and he checked them by doing his own experiments. He also found that new, heritable variations can appear suddenly, and he called a these variations mutations. Spetner (NBC) Page 19
Mendel's results surfaced, were considered significant, and were brought into the sphere of science's endeavors to build the paradigm that details how life works. Science kept accumulating new evidence and that evidence then, like today, was measured against current knowledge. Did adding the new evidence to the current base of understanding change the former thinking? Was Darwin's view fading? Let's consider how the scientific community would respond.
During the initial decades of the 20th century, Darwinism was overcome by the new biological evidence. Much of this comes from the development of genetics in the areas of transmission genetics and population genetics. If there was any hope that Darwinism would continue into the 1940's, the theory desperately needed a fix.
The subject was raised at a meeting of the Geological Society of America in 1941. A suggestion was made there that geneticists join hands with morphologists, taxonomists, and paleontologists to try and come up with a modernized version of Darwin's theory. They were asked to try to rebuild the theory using the latest findings in all these fields. Specialists responded to the call, and over the next few years produced a synthesis of their fields into a revised theory of evolution.
The scientists who participated in establishing the new theory included the geneticists, G. Ledyard Stebbins and Theodosius Dobzhansky, the zoologists Ernst Meyer and Julian Huxley, the paleontologists George Gaylord Simpson and Glen L. Jepsen, and the mathematical geneticists Sir Ronald A. Fisher and Sewall Wright. They called this theory the Modern Synthetic Theory Of Evolution. The theory gradually became known as the Neo-Darwinian Theory Of Evolution, and its framers and adherents became known as neo-Darwinians. Their agenda called for a theory that could explain the development of life in a natural way. If they could account for the development of all the present complexity of life from some sufficiently simple first organism, it would help pave the way for a theory of a fully natural account of the actual origin of life. Spetner (NBC) Page 20
So, the result of the transition was a measure of maintenance—the core ideas in Darwin's concept of evolution were carried forward. Yet not everything was static, there was some change to the view.
Spetner reflects on how neo-Darwinism rejected Darwin's a suggestion of environmental induction of heritable variations as well as inheritance of acquired characteristics. With the concept of genes in place, but not the structural evidence to come later, neo-Darwinians accepted a separation of somatic (i.e., body) and germ (i.e., gamete) cells. That is to say reproduction is carried on by a separate subset of cells. In this separation the neo-Darwinians did not link environmental influences nor acquired characteristics with affects on germ cells. To their thinking, heritable variation could only come from changes in the germ cells. As noted below and later in the WindowView, the environment may well play an incredibly important role. So, from the start, in this respect and perhaps elsewhere, the neo-Darwinians constrained the operation of evolution.
... they were unable to find a mechanism that could directly produce the genetic changes needed for descent. They therefore chose randomness as the source of the variations they needed—the very randomness that Darwin had rejected. Some of the variations are detrimental to the organism, but there may be some that are beneficial. A heritable variation of the latter kind, even if rare, will increase its number in the population by natural selection. Eventually, the change, if it enhances the organism's ability to survive and reproduce, will spread throughout the population.
The Neo-Darwinians then built their theory on random variation culled and directed by natural selection. They identified the heritable variations needed by the theory with the mutations discovered and named by De Vries some forty years earlier. A decade later, Watson and Crick identified the heritable variation with the random errors in DNA replication . Spetner (NBC) Page 21
WindowView also considers examples where the environment appears to play a role in expressing traits that are not made anew but are contained within the genetic information already stored within an organism. One implication here is that much more information is already stored within an organism (i.e., a species as a whole) than can be presently revealed by current evidence. We are led to assume new information results from new mutation events. The idea of randomness leans toward new mutations that surface coincidental to a 'need for an organism to adapt to change.' The idea that chance in some way operates as part of the neo-Darwinian view is certainly part of what is carried over from Darwin's thinking. Chance served an intended purpose to the exclusion of other possibilities.
If the Neo-Darwinian agenda had worked out, there would be no place for a Creator in and the origin of life except to establish the laws by which the evolution had taken place. Even that position would not be an honorable one if the appearance of man were not inevitable, as Steven J. Gould of Harvard University believes it is not [Gould 1989, pp. 292 ff]. Spetner (NBC) Page 22
Spetner repeatedly reminds us that the neo-Darwinians are unable to account for how new information builds over time such that evolution works as they say (see Spetner (NBC) Page 23). If life came from some simple ancestral form, then new information must be added over time. Without this there is no reasonable understanding of evolution; no means for life to evolve.
Mendel's observations helped to track how information was passed from generation to generation. He did not show how the information originated nor did he demonstrate change in that information—but more so how the information was expressed from generation to generation and how in some cases it might drop out of sight (i.e., for some offspring). The neo-Darwinian thinking still could do no better and could not account for the origin of the information within organisms.
A trend appears over time. The scientific community at large has attempted to continually carry the evolution theory forward and to adopt as much of the new evidence within this effort. Critical thinkers need to ask if every step in this effort is objective, subjective, or a bit of both.
A makeover came to Darwin's original theory in the 1940's. Today this is called the neo-Darwinian theory (Spetner abbreviates this as: NDT). The NDT was intended to answer difficulties that arose with new discoveries in biology. The public perception is that the NDT answers the problems with evolutionary theory. Now, half a century later, problems remain.
But science does not stand still. Discoveries in the last fifty years, and particularly in the last twenty, have been forcing evolutionists to patch in changes to the NDT. With the natural conservation of good science, they have been trying to keep those changes minor. The changes nevertheless are stretching the bond the holds the theory to the facts. That bond has been stretched to the breaking point, and evolutionists will soon have to it knowledge that the bond has already snapped They shall soon have to make a major innovation that will change the theory fundamentally, and force a basic change in the philosophy of evolution. A new theory of evolution is desperately needed.
In the NDT they have retained the two basic Darwinian novella of variation and natural selection. They have, however, sharpened Darwin's sometimes confused notion of variation, and insisted that it is spontaneous and random. Spetner (NBC) Page 50
What we see here is a perpetuation of ideas, yet as Spetner indicates the effort is wearing thin. If the old line does not hold, then where does science go next?
A basic dogma of the NDT is that mutations are not at all related to the needs of the organism. The theory is based on random genetic changes. If evolution were found to be driven by genetic changes that were not random, that were in any way a response to the environment or to the needs of the organism, it would contradict the theory. Evolutionists have a stressed time and again that the variations from which evolution stems are random in this sense. Spetner (NBC) Page 51
Neo-Darwinism arose to rethink Darwin's theory based on the new evidence, some of which comes from Mendel's work that ironically coincides with the timeframe of Darwin's own work.
As discussed later, Spetner goes further to develop an approach that focuses on existing information within organisms. While molecular genetics still works to sequence information in the genetic codes of many organisms, there are other genetic mechanisms that are already known but perhaps not well understood. These known mechanisms are part of what Spetner considers. Further, the role of the environment becomes much more important than previously thought. So, while neo-Darwinism may be failing, there are possible working alternatives. WindowView here is not the last word, but perhaps an initial look at something that will be a growing and significant story to science in the not so distant future!
Added Perspective:
There is much more to the story than what we've looked at here. The key concept is that genetics tells us something about information transfer. As evolution theory moved from the 19th to the 20th centuries, new evidence from all areas of science kept streaming in. Plant and animal classification, fossil evidence, understanding genetics,biochemical and molecular studies and more all added to a complex picture. The concepts of Darwin's day were kept alive within the neo-Darwinian framework. The fact that scientists held fast to some lines of Darwinian thinking may not be a surprise, for this reflects behaviors and beliefs that inter-mesh with and go beyond science alone. Keep this in perspective as you look at other facets of the view through this window.
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
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