Irreducibly Complex Controversy
As Robin Bernhoft correctly points out (“Confronting Creation’s Complexities,” July-August 2003), the apparently unexplainable cases of irreducible complexity in biology lie at the heart of Intelligent Design’s criticism of contemporary Darwinian theory. Recall that an irreducibly complex system is a system that “must not only be very complicated but also must need every one of its many parts to function. An irreducibly complex system cannot function if any one of its parts is taken away.”
Bernhoft and other proponents of ID argue that such a system “could not be created by a Darwinist approach, because Darwinism requires that complicated systems or organs be built up one piece at a time.” Though this is not explicitly stated, we are left to conclude that irreducibly complex systems, rather than being built up piecemeal over evolutionary time, appeared at one point in the history of life already assembled as a whole. Thus, one testable prediction of ID is that the molecular parts of an irreducibly complex system must be encoded by genes in the same genome. There should be no example of an irreducibly complex system whose parts are encoded in different genomes.
However, such an example exists. The human immunodeficiency virus is the virus that causes AIDS. The first step in the establishment of an HIV infection is the necessary interaction between the virus and the surface of the target host cell. This interaction is mediated by several molecular components. On the viral side, there is the envelope protein made up of two parts: gp120 and gp41. These make up the key. On the human side, there are two molecules that have been implicated in the interaction: CD4 and another human protein, most often CXCR4 or CCR5. These make up the lock.
Infection of the virus—the key fitting into the lock—involves a stepwise interaction of these components. First, the viral gp120 interacts with human CD4, an interaction that facilitates a structural change in viral gp41, which then allows it to interact with the second human protein. Completion of this step leads to fusion of the virus with the cell allowing infection to proceed—the key opens the lock. Notice that this multi-component system fulfills the definition of an irreducibly complex system—it is made up of interacting parts that are all essential for the function and therefore of the survival of the virus, hence the search for anti-AIDS drugs that can interfere with this process.
Notice too that this irreducibly complex system had to evolve through a stepwise process because it could not have arisen spontaneously as a single, unified whole. How could it, when its components are derived from two different organisms? But this is precisely the process that ID proponents claim could never happen! And the viral docking mechanism is only one example of an irreducibly complex system in HIV.
In the end, every multi-unit molecular machine that incorporates both human and viral components—and there are several in every virus—is irreducibly complex. Each one of them stands as a direct challenge to ID’s proposal that irreducibly complex systems cannot appear piecemeal. Bernhoft concludes his essay by suggesting that in his opinion, “Darwinism is not fit to survive.” It may be fitter than he thinks.
—Rev. Bro. Nicanor Austriaco, O.P., Ph.D.
Dominican House of Studies
Washington, D.C.
Robin Bernhoft replies: Dr. Austriaco’s illustration of the complex interaction between HIV and the host human cell is not an example of an irreducibly complex system. It is a complex relationship between two independent organisms that influence one another to the advantage of the virus and the detriment of the host. Such interaction, in one form or another, occurs with most, perhaps all, virus-host interactions. That the viral “key” happens to fit the cell’s “lock” says more about coincidence and the bad luck of the human host cell being in the wrong place at the wrong time than it says about Darwinian evolution.
What intermediate steps in each species would be “selected” to bring about this interaction? Are we to imagine HIV and the human host cell evolving in tandem toward this shared result? Are we to believe that the existence of a complex interaction between two pre-existing species has any application at all to the question of irreducible complexity “arising” within a single species? Must we ignore astronomical odds against the stepwise evolution of irreducible complexity? Or accept Gould’s “natural miracles”? By what evolutionary route would such things happen? Or is Dr. Austriaco merely trying to beg the question?
An irreducibly complex system, by definition, exists within a single species. Complex interactions between two or more species are interesting, but irrelevant to the issue of Intelligent Design. ID, like Darwinism, examines the origin of individual species and not interactions between two or more species.
He Has His Faults As Well
This Rock is always very good, but the October 2003 issue was “Great.” Your three articles on Pope John Paul II offered a balanced portrait of arguably one of the most influential popes in history. I don’t know whether history will bestow the title of “Great” on him, but it is interesting to entertain the discussions.
John Paul is without doubt a holy man, and I do admire him. However, many genuine admirers sometimes seem to forget that he is a man and, like all of us, has his faults as well. In fact, I found it ironic that during the recent just-war debates, a number of those supporting the Pope’s conclusions (to the point of insinuating that those who arrived at a different conclusion are not very good Catholics) are otherwise on the opposite side of Church teaching on matters such as abortion, contraception, homosexual marriage, women priests, and clerical celibacy.
I love John Paul II and pray for him. He is, as Karl Keating called him, a “pope of hope.” However, the lack of leadership in tolerating open dissent and defiance among cardinals, bishops, and priests troubles me. When men like Archbishop Keith O’Brien of Aberdeen, Scotland, who publicly disagrees with Church teaching on contraception, homosexuality, and clerical celibacy, are named to be cardinals, I have a hard time applying the title of “Great” to this pope.
— Paul Darcy
Boise, Idaho
We’re On One Year’s Probation
You have managed to do what no televangelist, door-to-door missionary, or anti-Catholic web site has been able to do. You put a little doubt into my Catholic faith with your articles by James Hitchcock and Fr. Brian Harrison on the Pope. It took a day to get over the doubt. I don’t know if I will be able to fully trust your magazine again. In this age when we, the laity, have to catechize ourselves, we look for an oasis of truth where we can rest assured we are safe. I thought This Rock was such a place.
In allowing readers to weigh the pluses and minuses, this magazine is leaning more toward journalism than apologetics.
This is what I will do in my library: For the next year, no Catholic Answers literature will be out. All back issues of This Rock will be put in storage. All books by Karl Keating will go there too. The thousand Pillar of Fire, Pillar of Truth pamphlets will be put away instead of being distributed. The Catholic Answers web page will be taken off of my “favorites” list. I will not listen to Catholic Answers Live on the Catholic radio station. No more contributions.
When I come back in a year, if all is better, then I will continue my support of this ministry. God bless, and I pray that you follow your original vocation.
—Tony Rocha
Freeland, Michigan
You Should Be Commended
My comments are probably not the first nor likely the last that This Rock will receive in regards to the October issue commemorating John Paul II’s twenty-fifth anniversary. Many, I surmise, are not going to be wholly complementary or positive in nature. While I don’t take issue with the editorial principle that was employed—discussing the strengths and weaknesses of this extraordinary yet mortal man—there are a few suggestions I have that reflect the possible misconceptions that others might get from this issue.
1. The biggest personal objection I have, and an immediate source of possible misconception, is the cover headline, “The Great.” This could portray, right off the bat, that the thrust of this issue is going to be a negative commentary about the faults and failures of this human individual. Although Karl Keating does note that he and the others are admirers of the Holy Father, I would think that you could have used a more generic headline, such as “Twenty-Five Years of John Paul II.” This title by itself wouldn’t give any sort of qualitative opinion or editorial sense. In addition, yours is a giveaway for the theme of one of the articles.
2. The only comment I have concerns Fr. Brian Harrison’s article about John Paul II possibly being declared “the Great.” In the opening paragraph he notes a belief that I share: JP II is a living saint and quite possibly deserving of being called “the Great.” He offers a conclusive opinion concerning the issue, but I think he might have wanted to make a similarly strong statement of JP II as a living saint. Some could take the exclusion of any mention at the end of JP II’s “saintliness” as meaning that Fr. Harrison also doesn’t think JP II is a saint either.
Overall, after several readings of these articles—which I must admit weren’t what I was initially expecting when it came to my house—I would think that you should be commended for deciding to take a look at this issue fairly from a positive and negative side.
—John Beutel
via the Internet