Evolution and Miracle of Design in the cell issues

[ Why Evolution is a part of science - An analysis]

By T.H.Huxley

In response to : http://groups.yahoo.com/group/mukto-mona/message/6967


This post was brought to my attention by Avijit Roy, one of the personal friends of mine and the member of another discussion board. I was invited by him to accept the challenge of that interesting post on that site, and I mirror my response here.

I'll first respond on moderator's introductory note, after that I'll make some comments on the Article "The miracle of design in the cell written by Mr Yahya (posted by Dr. Alamgir Hussain). Moderator's note, as it is posted here, as rhetoric, not as argument. It consists of three  �questions� (of creationist's) and a request for three definitions from evolutionists. I put the word �questions� in quotation marks because, as phrased, they are not really questions at all, but leading statements which bear little relationship to what is true. But, I will address them anyway.

Q1) So why is evolution given such a lofty status in science?

Evolution is given status because it has turned out to be the central organizing principle of the biological sciences. There does not exist a single specialty of biology that makes sense without it. It (and ONLY it) effectively explains taxonomy, genetics, population genetics, comparative anatomy, botany, zoology, biostratigraphy, paleontology, biochemistry, ecology�. Do you want me to continue?

Ideas achieve or lose �lofty status� in science based entirely on their explanatory power, and their ability to conform to the facts of nature better than competing ideas.

Before the idea of evolution was understood, there really WAS no �biological science.� There was simply �natural history.� Since then, evolution and evolution based research has turned the biological sciences into one of the gems in the crown of human scientific understanding and achievement.

In short, evolution has achieved its status as any scientific idea does. It has earned it because it is better at explaining the facts than all competing ideas.

Q2) Should not the theories of evolution be subjected to the same stringent tests as with true scientific theories?

This is not a question; it is actually a statement (and a false one at that). It is actually making the claim that the theories of evolution have NOT been subjected to the same stringent tests as other (the writer here misleadingly calls them �true�) scientific theories.

Unfortunately for the moderator, as he put such statement as creationist's argument, is simply wrong in his contention. There are no scientific theories which have been more thoroughly tested, evaluated, and �put through the wringer� than the theories of evolution.

What ARE all those biologists and paleontologists doing, if not testing these theories in their work every single day? What are ALL those articles in Science, and Nature, and Paleobiology about anyways, if not scientists testing these theories? How were able to reject Lamarck�s theory, and accept and improve on Darwin�s theory if we were not applying the �same stringent tests� as other theories?

Obviously, one may further confused (as my friend logical sometimes appears as well) by the difference between fact and theory. Theories do not BECOME facts, theories EXPLAIN facts. Evolution is both a FACT and a THEORY.

Darwin gave us a theory (natural selection) to explain a fact (descent with modification). It currently remains (with improvement and augmentation) the best theory we have to explain the fact of evolution. It may be further changed, modified or replaced, for science is tentative and progresses.

In the same way, gravity is both a fact and a theory. Less than a hundred years ago, we watched one theory of gravitation (Newton�s) replaced by another, better theory of gravitation (Einstein�s), but apples did not suspend themselves in mid-air awaiting the outcome of the debate.

Likewise, evolution has occurred and man has descended from apelike ancestors (and ultimately reptiles and fish) whether or not Darwin�s theory of natural selection ultimately proves to be THE right theory to explain it.

Q3) Why is evolution given the privilege such that even without definite proof, it is classified as science?

This �question� rather than making a claim that is untrue (as in Q2) simply decides to abandon the understanding of science altogether. There does not exist a SINGLE idea in science that possesses what anyone might call �definite proof.� Science is tentative, always open to revision, always available to be falsified and improved. Ideas that claim to possess �definite proof� are not science, they are dogma.

In reality, evolution and its theories enjoy no privilege with in science. They are of a status exactly equivalent to any other equally supported scientific ideas,

Finally, the �challenger� presents three requests for definition. Only the first two of them are terms of science, but that�s okay, I�ll discuss all three.

D1. Define evolution.

Although it has several definitions, it is clear that the author is looking for a definition relevant to this discussion, so that is the only one I will give.

Evolution is the process by which living organisms are modified over multiple generations allowing for speciation and diversification and resulting (over longer periods) in dramatic genetic and morphological change.

Put simply, it is the idea that all living organisms on the planet earth have descended from one, or a very few number of common ancestors.

D2. Define species.

A species can be defined either taxonomically or genetically.

Taxonomically, a species is any population of organisms that share enough similarity to be included in the same binomial taxon. Example: our species is Homo sapiens. Orangutans are Pongo pygmaeus. Dogs are Canis familiaris.

Genetically, a species is any population of organisms than can interbreed successfully and produce fertile offspring. For example, horses and donkeys are DIFFERENT species because their offspring (mules) are sterile. Kodiak bears and Grizzly bears are the SAME species, because their offspring are fertile. A species, therefore, is a unit composed of organisms that can successfully interbreed. Should a genetic barrier to reproduction arise between two populations of what was one species, then we now have at least one new species, and we say that �speciation� has occurred.

3. Define missing link.

�Missing link� is not a scientific term. It is a newspaper term that was popularized by the commercial media during the last few years of the 19thtcentury. It was originally coined to refer to the �missing link� between humans and apes, and was regularly applied to fossil findings that fit the preconceived popular notions of what such a �link� might look like. So, Neandertals were once referred to as �missing links� (even though they had actually been found) as was Dubois� Java Man (Homo erectus), Peking Man (Homo erectus), Leakey�s �Zinjanthropus� (Australopithecus boisei), Darts �Southern Ape Man� (Australopithecus africanus) and Johansen�s �Lucy� (Australopithecus afarensis).

The biggest problem with the term �missing link� is that it assumes that evolution works in a linear, directional way. And it does not. But popular misconceptions of this type still find their way into the press accounts of paleontological discoveries, as well as into the rhetoric of creationists.

Now I I'll make some comments on the Article "The miracle of design in the cell written by Mr Yahya. I again thank  Avijt, for sharing this fascinating example of creationist �gee whiz� literature. I call it �gee whiz� because it as a great example of the stock creationist �argument from ignorance.� The underlying message is, �The cell is just SO amazing, that I can�t imagine how it might have evolved. And since I can�t imagine it, it must not have happened.

I cannot tell you how often I find myself giving thanks that science and scientific progress is not limited by the �imaginations� of some of its detractors. I am grateful for all the imaginations better than my own that have delivered us the modern technological world in which we live. I certainly, as a child, could not have imagined much of what I now encounter routinely during my day. But I never for a second would have held MY imagination up as the standard for what was possible.

The article, �The miracle of design in the cell,� depends on the reader accepting blindly a number of explicit assertions and some additional implications that are simply not true. All else follows from accepting those initial false premises. So rather than harp on the silly anthropomorphism that allows the author to call the cell membrane �conscious� and �wise,� I�ll concentrate on exposing the falsity of the premises on which the article is based.

The author sets us up by claiming that �the cell is by far the most complex structure mankind has ever encountered, as is also agreed by the scientific community.� This is so far from the truth that I had to stop myself from laughing out loud when I read it. Some cells are VERY complex, true. Most are not. But if a cell is complex, wouldn�t a combination of two or more cells be at least twice as complex?

I have never heard or read a single scientist make such a silly claim as this. I for one would vote for the human brain as �the most complex structure mankind has ever encountered,� but that�s just me. Any representative sampling of a dozen scientists would come up with at least three or four other candidates for the position.

The author extends this claim of transcendent complexity with his �gee whiz� trump card. He writes, �In order for the cell to survive, all the basic components of the cell, each performing many vital functions, have to be intact. If the cell came into existence by evolution, then millions of its components had to simultaneously exist in the same place and they had to come together in a particular order and plan.�

It is here that the author stakes his entire argument, and it is here that his argument completely falls apart, for this statement is simply, objectively, demonstrably not true.

It is clear that cells did not (and did not NEED to) arise suddenly with all the current complexity of the most sophisticated cells already in place and fully functioning.

They, like all other biological entities, can be shown to have developed over time in a stepwise, evolutionary process.

The fact that there are different kinds of cells TODAY (some complex, some not) proves that a cell DOES NOT need all these components to exist, or to survive, or even to thrive. The complex cells of the type discussed by this author are only the end result of a lengthy evolutionary history that included stages when cells did less and were less complex.

Look (for just one example) at the difference between Prokaryotes and Eukaryotes. Prokaryotes are living cells, and include Monera (simple bacteria) and Archaea. Simply stated, prokaryotes are molecules surrounded by a membrane and cell wall. Prokaryotic cells lack characteristic eukaryotic subcellular membrane enclosed "organelles", but may contain membrane systems inside a cell wall.

These cells do not need mitochondria, or golgi apparatus, or ribosomes, or chloroplasts, or even nuclei. They are VERY SIMPLE organisms, certainly not among the �most complex structures that mankind has ever encountered.� They lack MOST of the �components� and are unable to perform MOST of the �vital functions� that the author insists a cell requires �in order to survive.� Yet they survive quite well, and are arguably the most successful organisms on the planet. They�ve been around longer than any other living thing, they routinely kill and eat us more complex organisms by the millions, and while we often talk of an �age of reptiles� or �age of mammals� the truth is that we have had only one age on Earth, and it�s ALWAYS been the age of bacteria.

The evolutionary pathway from prokaryote to eukaryote is actually becoming quite clear. Complex eukaryotic cells appear to be symbiotic communities of multiple prokaryotes. Mitochondria (for example) even have their own DNA, since they were almost certainly at one time independent organisms. Chloroplasts in plants appear to have a similar origin.

But the point here is that it is NOT a valid argument to take a complex, eukaryotic cell as an example of a �starting point� for anything. It is (I�ll say it again) an end result of an evolutionary process that had much simpler cells in its past.

This is where one is compelled to ask the question as to whether the author REALLY couldn�t imagine an evolutionary scenario, or whether they were simply being disingenuous. For seriously, how much imagination does it take to read a text on cell biology and SEE FIRST HAND (no imagination required) that there are still living simple cells that do NOT need to perform all the �vital functions� this author insists are necessary?

Of course, at this time the author is likely to say, �Well, then BACTERIA are THEMSELVES too complex to have suddenly arisen with everything in working order.� To which I would counter, they DIDN�T �suddenly� arise either, but also came from less complex forerunners. Take a virus for example: We can�t even decide whether or not they�re actually alive, and all they consist of is a protein shell and a piece of genetic material.

His description of the form and function of a cellular membrane is too "over the top" to really take seriously. Ignoring his insistence on conferring the cell membrane with such attributes as wisdom, consciousness, memory, decision making skills, and even (can you believe it) list keeping, he seems to have a vision of membrane performance that is at huge variance with reality. In fact, he seems to elevate simple osmosis to a status of artistic virtuosity that even a Picasso or a Beethoven would despair of achieving.

Do cell membranes �never allow in more than what the cell needs?� No, they OFTEN let in more than what the cell needs.

Is it true that �there is not a single unnecessary, purposeless molecule in a cell?� Of course not. Even most of our genetic material is �unnecessary and purposeless,� let alone the random chemicals and molecules that flood our systems (and our cells) from a purely environmental basis.

Does the cell membrane �not permit even minor errors?� What nonsense is that? Every cell membrane permits many errors. Most cells can handle a certain amount of trauma, uncertainty and suboptimal performance. And those that can�t actually do die. All the time. Every day. By the millions.

It helps no one�s argument to argue from fantasy, rather than reality. The author�s constant attitude of �gee whiz, isn�t that amazing� might be ameliorated just a little if he had a more realistic understanding of the object of his amazement.

I guess in final analysis, the argument is false because it ASSUMES the act of creation rather than tries to prove it. When the author is saying that all these things had to come together fully formed at exactly the same time, he�s not saying that evolution is impossible, because evolution clearly doesn�t require that. His posited straw man of simultaneous, fully functioning, complex eukaryotes sounds a LOT more like creation than it does like evolution.

And I would have to agree with the circular argument that for creation to have occurred, creation has to have occurred. But science does not insist of special creation for living cells, only this author does.

T.H.Huxley redux