Darwin, Then and Now

Archive for the ‘What Darwin Said’ Category

Long denigrated as vestigial or useless structure, the human appendix is now known to have a number of specific functions. The most widely recognized function is as a “safe house” for the beneficial bacteria living in the human gut.” There are approximately 500 species of bacteria in the gut alone—the continued presence of beneficial bacteria is essential for good health.

ScienceDaily in an article entitled “Appendix Isn’t Useless At All: It’s A Safe House For Good Bacteria,” October 8, 2007, William Parker, Ph.D., assistant professor of experimental surgery along with R. Randal Bollinger, M.D., Ph.D., Duke University professor emeritus noted—”Our studies have indicated that the immune system protects and nourishes the colonies of microbes living in the biofilm. By protecting these good microbes, the harmful microbes have no place to locate. We have also shown that biofilms are most pronounced in the appendix and their prevalence decreases moving away from it.” One of the functions of the appendix is to serve as a microbe storehouse.

According to their study published in the Journal of Theoretical Biology, the bacteria in the human gut functions to digest food and produce vitamins, like Vitamin K—essential to coagulation. In the event that bacteria in the intestines become unbalanced, or taken over by opportunistic organisms such as cholera or amoebic dysentery, the appendix functions to reboot the bacterial flora. Parker explains the mechanism: “Once the bowel contents have left the body, the good bacteria hidden away in the appendix can emerge and repopulate the lining of the intestine before more harmful bacteria can take up residence.”

“Darwin simply didn’t have access to the information we have,” explains Parker. “If Darwin had been aware of the species that have an appendix attached to a large cecum… he probably would not have thought of the appendix as a vestige of evolution.”

When Jerry Coyne (2009), professor at the University of Chicago, writing in his book, Why Evolution is True that “our appendix is simply the remnant of an organ that was critically important to our leaf-eating ancestors, but is of no real value to use,” excluded known evidence. Continued adherence to the vestige status of the appendix by evolutionists requires rejection of the scientific method.

“Maybe it’s time to correct the textbooks,” says William Parker, Ph.D., assistant professor of surgical sciences at Duke and the senior author of the study. “Many biology texts today still refer to the appendix as a ‘vestigial organ.’”  

Vestiges  are tauted as evidence for biological evolution based on the Larmarckian concept of “use and disuse” that Charles Darwin reluctantly, yet fully accepted by the 6^th edition of The Origin of Species in 1872.

In the 1^st edition Darwin wrote that“use and disuse seem to have produced some effect” that was later changed to “use and disuse seem to have produced a considerable effect” in the 6^th edition. For Darwin, the importance of “use and disuse” increased from “some effect” to “considerable effect.”

In this series, we are examining the concept that the human appendix is a vestige structure through the process of “disuse.” Vestiges are thought to be biological elements that have lost their function through “disuse.” At issue is—what is the evidence that the process of “disuse” can actually produce vestiges?

In the decade following the publication of the 6^th edition, German biologist August Weismann, at the University of Freiburg, launched the first scientific inquiry to directly challenging Darwin’s theory. Now known as the “Weisman Barrier” in 1883 Weismann cut off the tails of mice from twenty-one generations. Seeing that the twenty-second generation still had tails, Weismann concluded that the evidence contradicted Darwin’s theory of “disuse” and that despite obvious reasons for change in the mice, “continuity” was observed, not new variations.

The concept of the Weismann Barrier became central to the emerging  Modern evolutionary synthesis. “Disuse” alone simply does not result in vestige structures. Ernst Mayr, known as Darwin’s bulldog of the twenty-first century, called Weismann “the second most notable evolutionary theorist of the nineteenth century, after Charles Darwin.”

Evidence from the Weismann Barrier continues to stand unchallenged, now for over 100 years. Even more to the point, after thousands of years of circumcision, “disuse” has failed to any effect on human anatomy. Without scientific experimental evidence demonstrating that “disuse” can result in any biological changes, the concept of vestige as evidence for evolution remains untenetable.

Other known vestige problems for evolution include, 1) the appendix is not found systematically found through nature, even in mammals; 2) “vestige” structures are now known to be functional. These evolutionary contradictions for vestiges continue to undermining evidence for evolution.

In the up-coming posts, we will continue to explore why these last two problems have completely undermined the concept that the human appendix is a vestige structure.

Charles Darwin attempted to avoid the use of the term “vestiges” largely because the term had been associated with the “erroneous” Larmarckian concept of “use and disuse” that was only “veritable rubbish.”

Jean-Baptiste Lamarck (1744 – 1829) was a member of the French Academy of Sciences and was appointed to the Chair of Botany in 1788. When the Muséum national d’Histoire naturelle was founded in 1793, Lamarck was appointed professor of zoology. In 1801, he published Système des animaux sans vertèbres, a major work on the classifications and coined the term invertebrates. Lamarck is thought to be the first use the term biology in its modern sense. Lamarck continued his work as a premier authority on invertebrate zoology.

Darwin did credit “Lamarck as the first man whose conclusions on the subject excited much attention.… In these works he up holds the doctrine that all species, including man, are descended from other species.”

Lamarck’s theory of evolution, which he referred to as “transformism,” was based on the idea that individuals develop new traits during their own lifetimes by “use and disuse” and transmit them to the next generation. Larmack writes – “Progress in complexity of organization exhibits anomalies here and there in the general series of animals, due to the influence of environment and of acquired habits.”

The giraffe served as Lamarck’s classic example of evolution through “use,” acquiring longer necks in successive generations in competition to reach the ever-scarcer leaves higher in the trees. In illustrating Lamarck’s views on adaptation, Darwin wrote, “To this latter agency he seems to attribute all the beautiful adaptations in nature; such as the long neck of the giraffe for browsing on the branches of trees.”

For Darwin, however, this explanation was simply not scientific – “Lamarck, who believed in an innate and inevitable tendency towards perfection in all organic beings, seems to have felt this difficulty so strongly that he was led to suppose that new and simple forms are continually being produced by spontaneous generation. Science has not as yet proved the truth of this belief.”

One of the most eminent pre-Darwinists was Charles Darwin’s own grandfather, Erasmus Darwin (1731–1802). Erasmus discussed his ideas at length in a two-volume work, Zoonomia, published in 1794. Erasmus wrote that “all … have risen from one living filament.”

Erasmus’ book was widely popular in Western Europe- even translated into German, French, and Italian. Erasmus envisioned that the driving force behind species modification was a result of “lust, hunger, and danger.” In line with Greek philosophy, Erasmus envisioned changes by “continuing to improve its own inherent activity.”

Actually how these “improvements” developed was completely unknown to Lamarck and Erasmus—evolution was a philosophy, not a science. The unknown cause of “improvements” is what drove Darwin to discover the underlying laws of nature—scientifically. Writing in the preface of The Origin of Species, Darwin suggests how Erasmus’s work, although “erroneous,” may have influenced Lamarck: “It is curious how largely my grandfather, Dr. Erasmus Darwin, anticipated the views and erroneous grounds of opinion of Lamarck in his Zoonomia.”

For Lamarck, new characteristics are acquired through the process of “use and disuse.” Darwin’s grandfather, Erasmus Darwin, was a Lamarckian evolutionist. Charles Darwin, however, in pursuit of a “scientific theory” of evolution, initially opposed Lamarckian evolution, only granting the theory marginal support.

In a letter written to J. D. Hooker in 1844, Darwin wrote, “Heaven forefend me from Lamarck nonsense of a ‘tendency to progression.’ … But the conclusions I am led to are not widely diff erent from his, though the means of change are wholly so.” “With respect to books on this subject,” Darwin continues, “I do not know any systematic ones, except Lamarck’s, which is veritable rubbish.”

Although attempting to distance himself from Lamarck’s concepts of “use and disuse” and “vestages,” Darwin distain for “use and disuse” eventually waned as causes for the origin of variation required for the actions of natural selection remained Darwin’s largest unsumountable enigma.

Since then, the term, “vestiges” has once again gained prominence over “rudiments,” as has Larmarckian concepts of evolution. The question remains, however, are structures classified as “vestiges” evidence of evolution? Specifically, have vestiges seemingly lost all or most of their original function in a species through evolution?

To address answers to these questions, we will be examining the most popular example of vestiges—the mammalian appendix in the up-coming posts.   

Charles Darwin only uses the term “vestiges” five times in The Origin of Species. Ironically, since then vestiges have become synonomous with evolution. The emenent evolutionist, Douglas Futuyma, Professor of Ecology and Evolutionary Biology at the University of Michigan, notes that vestigial structures make no sense without evolution.

In this first in a series, we will discover how structures labeled vestiges have played an important role as evidence for the theory of evolutionary. By the time The Origin of Species was published in 1859, vestiges had already been a hot topic. It was Robert Chambers in the publication of his book entitled Vestiges of the Natural History of Creation in 1844 that popularized the concept of vestiges. Chambers brought together various ideas of stellar evolution and progressive transmutation of species. The book was a best-seller is considered largely responsible for causing a shift in public opinion that paved the way for the general acceptance of evolution following the publication of  The Origin of Species.

While agreeing with the general concept of evolution, Darwin took many exceptions with Chamber’s perspective on vestiges and the concept that evolution occurs by sudden changes in nature. Darwin wrote – “The author [Chambers] apparently believes that organisation progresses by sudden leaps, but that the effects produced by the conditions of life are gradual.”

Perhaps because of these differences with Robert Chambers, Darwin even avoided defining the term “vestiges” in The Origin of Species. In the Glossary, however, Darwin defines a related term: “RUDIMENTARY.—Very imperfectly developed.” In The Origin of Species, the term “rudimentary” appears 101 times.

Darwin envisions rudimentary structures to be the result of two different dynamics: 1) as structures “imperfectly developed”—emerging, and 2) as structures in disuse undergoing loss of function—elimination. Darwin writes – “Rudimentary organs will speak infallibly with respect to the nature of long-lost structures”—a Lamarckian disuse concept. Darwin explains that rudimentary structures continue to exist because “natural selection… had no power to check deviations in their structure.”

Today however, only the process of elimination due to the disuse concept is thought to be in operation. WIKIPEDIA.org states: “Vestigiality describes homologous characters of organisms that have seemingly lost all or most of their original function in a species through evolution. Answers.com defines vestige structures, as “A rudimentary or degenerate, usually nonfunctioning, structure that is the remnant of an organ or part that was fully developed or functioning in a preceding generation or an earlier stage of development.”

 This takes us to the next question – why did Darwin largely attempt to avoid the term vestiages that was associated with the Larmarckian concept of use and disuse?

Jerry A. Coyne, one of the leading evolutionists at the University of Chicago, in his new book entitled Why Evolution is True (2009) writes “much confusion and misunderstanding surrounds evolution” even though “the modern theory is easy to grasp.” The question is how can a theory be “easy to grasp” and still be surrounded by “much confusion”?

But what could the confusion be over? Here are some examples.  Charles Darwin wrote in The Origin of Species - “There is no logical impossibility in the acquirement of any conceivable degree of perfection through natural selection”. Coyne contradicts Darwin by stating – “natural selection does not yield perfection”. Over a trivial issue, confusion reigns over whether natural selection can or cannot produce perfection in nature.

Presumably, to show how easy the theory of evolution is to understand, Coyne features what he calls the six basics of evolution: “evolution, gradualism, speciation, common ancestry, natural selection, and nonselective mechanisms”. For Coyne, natural selection is not the exclusive driving force of evolution.

Niles Eldredge, evolutionary biologist and curator of the American Museum of Natural History, disagrees. Niles Eldredge, architect  and designer of the museum’s currently touring Darwin exhibit in the companion book Darwin, Discovering the Tree of Life (2005), credits Darwin with discovering the actions of natural selection—the essence of evolution: “When [Darwin] formulated the principle of natural selection, he had discovered the central process of evolution.”

Unlike Coyne, Eldredge envisions evolution acting exclusively through the process of natural selection: “A century and a half ago, Charles Darwin offered the world a single, simple scientific explanation for the diversity of life on Earth: evolution by natural selection.” Unlike Coynes six basics of evolution, Eldredge uses a VISTA acronym for natural selection that stands for Variation, Inheritance, Selection, Time, and Adaptation.

Differences in approach even between Coyne and Eldredge, exemplify why evolution theory continues to be confusing—even on the basics. The teaching of evolution is in chaos. Coyne pines “most of my university students who supposedly learned evolution in high school, come to my courses know almost nothing about this central organizing theory of biology.” Could it be because a unified theory of evolution simply does not exist?

Even university science major graduates seem to be no better. T. Ryan Gregory and Cameron A. J. Ellis, in their paper entitled “Conceptions of Evolution Among Science Graduate Students” published in BioScience 59(9):792-799 (2009), surprizingly found that less than 30% of students pursuing advanced science degrees could correctly identify even the basic principles of evolution.

The reason is—a comprehensive theory of evolution simply does not exist. Even with the convening of the most respected evolutionary scientists at the Altenberg Summit in 2008, no consensus was reached on a comprehensive theory of evolution.

Given the flood of available evidence, in the wake of Crick’s Central Dogma collapse, evolution is a theory that remains in chaos—now more than ever.