By Stanley K. Sessions
An open letter to Tom Sears:
Dear Tom,
In recent newspaper columns on evolution in The Daily Star (Aug. 7, 21, and Sept. 4), you wrote you have the "greatest respect" for scientists and science and then attack scientists as "arrogant" for not considering creationism and intelligent design (ID) valid alternative "theories" to the theory of evolution.
Then you expound on your understanding of the theory of evolution, which appears to be informed mainly by creationist dogma. I feel you have missed an opportunity to inform and enlighten, and instead are fanning the flames of discord and confusion by spreading misinformation about something you apparently know little about. This is disappointing to see in a fellow educator.
If you had asked a scientist or perused a basic science or biology textbook, you would have learned that creationism and ID have been thoroughly examined by the scientific community and are not considered to be valid alternative scientific theories to the theory of evolution.
You also would have learned why: Creationism is a religious idea based on belief in the supernatural, and so is outside the realm of science; proponents of ID seldom mention God, but the idea is based on statements about biology that are demonstrably false (e.g. "irreducible complexity"). A supernatural designer is implicit, and ID has been thoroughly discredited by the community of scientists.
I recommend Francis Collins' book "The Language of God" if you want to understand the perspective of a scientist who believes in God (Collins is a born-again Christian and head of the NIH human genome project). Collins argues that religion and science are compatible, but despite being an evangelical Christian, is very critical of ID. He warns that ID is a "sinking ship" that is more likely to damage faith because it makes a laughingstock of those who support it.
A few minutes of study would also have taught you that scientists do not consider the theory of evolution invincible. An important part of the definition of a scientific theory or hypothesis is that it is falsifiable.
If you had asked a scientist, you would also have learned that the theory of evolution, like science in general, cannot "prove" anything to be true. That is a fundamental aspect of science that so many people just do not seem to get. Science makes a case, like in a court of law, based on available evidence, "beyond reasonable doubt," and that is all.
To date, nobody has been able to come up with a valid alternative scientific (i.e. falsifiable) theory to explain the origin and diversity of life. The theory of evolution is imminently falsifiable, and God knows scientists have worked very hard over the years to find some alternative.
So far, we have failed, and so the theory of evolution is considered to be one of the strongest scientific theories we have. With the advent of molecular biology, has become the central theory of all of biology.
If you had consulted an evolutionary biologist, you would also have learned that "microevolution" (evolution within a species) and "macroevolution" (evolution above the species level) represent the two ends of a spectrum, or continuum, of evolutionary change.
This is because it is so easy to extrapolate from the genetic differences seen within a species to those seen between species, especially given millions of years and extinction of intermediate forms.
This view is supported by examples of species that are in the process of splitting, and because it is possible to create new species through hybridization (all well-known textbook examples).
It is also supported by the fossil record, often incomplete and inadequate but is, for some organisms, crammed with intermediate forms, a plethora of "missing links" that abundantly support gradual evolutionary change.
The human fossil record is an outstanding example, where there is such an abundance of "intermediate" forms that it is difficult to know which one, if any, was our direct ancestor.
Even a cursory look into a textbook on evolution (or the Internet; I recommend the Tree of Life, www.tolweb.org/tree/) would have shown the theory of evolution does not, as you put it, present life as a chain of increasing complexity, from "primordial soup" through cells and fish and eventually to man.
We have known this since Darwin wrote "The Origin of Species" more than 150 years ago! This book is another one to put on your recommended reading list.
Likewise, your statement that "Naturalism, mutation and blind chance are supposed to explain how we evolved" seems disingenuous at best.
The theory of evolution holds, in very simple terms, that the raw material for evolution is genetic variation, which is the product of random mutation. However, evolution is caused mainly by natural selection, which is not a random mechanism or blind chance.
This fundamental misunderstanding of basic evolution leads you to make other false and misleading statements, including the one about proteins (which appears to have been lifted right out of creationist dogma). No evolutionary biologist claims that a functional protein could have evolved through "simple chance," as you put it.
Natural selection is not random chance, Tom! Like a horse race where the fastest one wins, the winners in natural selection are those who produce the greatest number of viable offspring such that their genes are transmitted into future generations.
Natural selection is the only mechanism we know of that can cause adaptive evolution. Computer models have made it clear that natural selection is such a powerful evolutionary force that it can cause extremely complex structures to evolve rapidly. Compound invertebrate eyes (the most complex known), for example, had already evolved 500 million years ago.
Finally, you are incorrect to say that evolution cannot explain the origin of life. The theory of evolution does what scientific theories do: it provides explanations that best fit what we know from material evidence. We know what had to have occurred, even though we do not yet (and may never) know exactly how. But again, science does not have to prove things to be true, only make a reasonable case supported by the bulk of available evidence.
The Miller-Urey experiments that you described led, in just a few weeks, to the spontaneous formation of all of the key molecules of life, and later experiments showed that these included building blocks of RNA and DNA. Scientists have already created an artificial functioning virus.
But even if we succeed in creating an artificial living cell in the laboratory, it does not prove we know how it occurred more than 3.5 billion years ago. Once such an entity began reproducing, the rest is (evolutionary) history.
Tom, I hope you realize that I am writing this to you with the best of intentions. Your newspaper column is potentially a great opportunity to inform and educate, as well as provoke.
As a fellow academic, I know you share my concern that education is an uphill struggle and that the spread of misinformation, even if unintentional, makes our job that much harder.
Sincerely yours,
Stanley K. Sessions
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Sessions is a professor in the biology department at Hartwick College.
