Supplementary Quotes by Carl Cox

The process of evolution, by Gould

"The modern theory of evolution does not require gradual change. It in fact, the operation of Darwinian processes should yield exactly what we see in the fossil record. It is gradualism that we must reject, not Darwinism. [.]

Eldridge and I believe that speciation is responsible for almost all evolutionary change. Moreover, the way in which it occurs virtually guarantees that sudden appearance and stasis shall dominate the fossil record. All major theories of speciation maintain that splitting takes place rapidly in very small populations. The theory of geographic, or allopatric, speciation is preferred by most evolutionists for most situations (allopatric means 'in another place'). A new species can arise when a small segment of the ancestral population is isolated at the periphery of the ancestral range. Large, stable central populations exert a strong homogenizing influence. New and favorable mutations are diluted by the sheer bulk of the population through which they must spread. They may build slowly in frequency, but changing environments usually cancel their selective value long before they reach fixation. Thus, phyletic transformation in large populations should be very rare-as the fossil record proclaims. But small, peripherally isolated groups are cut off from their parental stock. They live as tiny populations in geographic corners of the ancestral range.

Selective pressures are usually intense because peripheries mark the edge of ecological tolerance for ancestral forms. Favorable variations spread quickly. Small peripheral isolates are a laboratory of evolutionary change. "What should the fossil record include if most evolution occurs by speciation in peripheral isolates? Species should be static through their range because our fossils are the remains of large central populations. In any local area inhabited by ancestors, a descendant species should appear suddenly by migration from the peripheral region in which it evolved. In the peripheral region itself, we might find direct evidence of speciation, but such good fortune would be rare indeed because the event occurs so rapidly in such a small population. Thus, the fossil record is a faithful rendering of what evolutionary theory predicts, not a pitiful vestige of a once bountiful tale."

- "The Episodic Nature of Evolutionary Change," Error! Bookmark not
defined., New York: W. W. Norton, 1980, pp. 182-184.

Monday, May 27, 2002

Is evolution like a well-tuned car that purrs down the road at a steady pace? Or is it more like an aging, rattling jalopy that often lurches forward?

The aging jalopy is a handy metaphor for the evolutionary theory popularized by Stephen Jay Gould, who died of cancer last week at age 60. Thanks to Gould's numerous popular writings, his theory known as "punctuated equilibrium" has been at the center of a major scientific debate since theearly 1970s.

Gould and his colleague Niles Eldredge argued that the evolution of life isn't a slow, steady, gradual process, as conventional scientific wisdom held. Rather, they said, evolution is a multi-million-year saga usually characterized by brief, sudden shifts separated by long periods of little or no change.

In recent years, some experts claim, the weight of evidence has increasingly favored the Eldredge-Gould hypothesis. Others aren't so sure. "Up to now proponents (of punctuated equilibrium) think they've been vindicated, while those of gradualism claim the same," says University of California at Berkeley paleontology professor Kevin Padian, a leading admirer of Gould.

In an outline for his course, Integrative Biology 100b, Padian calls
Eldredge and Gould's 1972 article "perhaps the most influential and
frequently cited paper in paleontology in this century. It is also one of
the most far- reaching theoretically, and one of the best written papers you
will find in recent science . . ."


Among the evidence supporting punctuated equilibrium, said David Jablonski, chair of the committee on evolutionary biology at the University of Chicago, is "an impressive array of examples in the fossil record, from snails to horses . . . a core of solid analyses that are very convincing."

One scientist analyzed the evolutionary "trees" of 34 different types of scallops and found only one that displayed gradual evolution over time. The remaining 33 stayed pretty much the same from generation to generation, Jablonski says. Another scientist found gradualism in only eight of 88 lineages of trilobites.

Even so, traditions die hard, and critics have gone to great lengths to try to discredit punctuated equilibrium.

One renowned evolutionary thinker, John Maynard Smith of England, wrote in 1995: "Because of the excellence of his essays, (Gould) has come to be seen by nonbiologists as the pre-eminent evolutionary theorist. In contrast, the evolutionary theorists with whom I have discussed his work tend to see him as a man whose ideas are so confused as to be hardly worth bothering with, but as one who should not be publicly criticized because he is at least on our side against the creationists."


Normally, even intense scientific disputes are unknown to the public: They rage behind the closed doors of laboratory and university seminar rooms. But punctuated equilibrium became a very public issue in the 1970s, thanks partly to Gould's prolific popular science writing in books, essays, and his column for Natural History magazine.

The son of left-leaning New York Jews, Gould hated elitism. A gifted and witty writer, he decided to bring the debate to the attention of ordinary folks -- the same kinds of folks with whom he rubbed shoulders and gobbled hot dogs at New York Yankees baseball games.

Punctuated equilibrium "went public" for another reason, too: the emergence of the modern creationist movement. Gould and Eldredge's dispute with other evolutionary theorists thrilled creationists, who misinterpreted it as a sign that evolutionary theory was on its deathbed.


That angered Gould, an agnostic. Few things made him madder than having to deny the charge that punctuated equilibrium theory played into the hands of creationists.

Punctuated equilibrium "is still very much a controversial theory," but "is fully compatible with what we term neo-Darwinism," said Peter D. Roopnarine, chair of invertebrate zoology and geology at the California Academy of Sciences. "Creationists unfortunately, and very incorrectly, seized upon this as a challenge to Darwin and evolution."

The story of punctuated equilibrium is a classic example of how scientists (like the rest of us) sometimes see what they expect to see, not what's really there in front of their eyes. Reality is in the eye of the beholder.

Traditionally, scientists looking at the fossil record assumed they didn't see strong evidence of gradual evolution because the fossil record was woefully limited. If the fossil record were more complete, they assumed, they'd see overwhelming evidence of gradual organic change, just as
characters on movie film gradually shift position from frame to frame.


But in fact, Gould and Eldredge argued, the fossil record was quite rich in some places and very adequate for seeing patterns of stasis, not gradual change.

The problem is that "people just didn't see the evidence of stasis," says geologist-paleontologist Carlton Brett of the University of Cincinnati.

"They didn't see the obvious pattern of stasis even though it was right in front of their eyes. Because they had a preconceived idea that they should be seeing gradual change, they failed to see the obvious pattern of stasis.

"This is a common problem in science: Sometimes we don't see what we
don't expect to see," Brett said. "The influence of a particular paradigm is
so strong that it may make people put blinders on, and it may prevent people
from seeing obvious patterns."


What causes stasis? That's still a hotly debated topic.

Gould suggested that "rapid" evolution -- say, over thousands of years, a blink of an eye in geological time -- might occur when a small splinter group of a species becomes geographically separated from its peers. For example, sea- level rise might turn a peninsula into an island, isolating a small number of animals from their kind on the other side of the water.

Result: When these isolated creatures undergo random mutations, as all species do from time to time, the mutations persist rather than being genetically washed out by genetic "blending" with a larger group of animals.

Over time the splinter group accumulates many mutations. Eventually it may become a different species.

"Of all Gould's contributions, in my mind nothing is more important than his establishment of stasis as a real phenomenon," Brett says. "This notion of stasis is something that people really didn't think about prior to 1972."


Brett recalls Gould as an effusive, brainy, sometimes arrogant raconteur who was capable of real warmth -- a man who would happily chat about evolution while repairing a flat tire in the middle of a field trip, as he did on an outing with Brett.

Gould dedicated his last book, the 1,500-page "The Structure of Evolutionary Theory" (Harvard University Press) to Eldredge and their colleague Elizabeth Vrba. The book's dedication reads, in part: "May we always be the Three Musketeers / Prevailing with panache."
E-mail Keay Davidson

Tuesday, May 21, 2002

Much of the scientific controversy over Gould's work concerned matters of definition. Few evolutionary theorists deny that evolution sometimes happens quickly and is a highly chancy affair. Rather, the key questions are: How quickly? and how chancy?

Gould argued that some creatures undergo dramatic changes in shape and size over time periods of thousands of years -- periods that are a blink of an eye, geologically speaking. He was furious when creationists misquoted his views in support of their belief in divine creation.


Though this site is supposed to be taking evolution's truth for granted, I suppose it would be nigh impossible to prevent those Mormons who are not persuaded by it to sound off. Rather than interupting every posts discussion with a huge side track on this issue, perhaps it would be better to let people air their grievances here.

3/21/2005 01:01:00 AM  

Jeff said:

"Though this site is supposed to be taking evolution's truth for granted, I suppose it would be nigh impossible to prevent those Mormons who are not persuaded by it to sound off"

Jeff - since any
"reconciliation" will involve doctrinal issues, I think it would be a mistake to exclude "non-beleivers" from the discussion for the reason that they will see weaknesses in your reasoning that you may not, and may have access to doctrinal sources that you may overlook.

IF you attempt to leave the entire reconciliation effort in the hands of what still remains a small minority of Mormons - whenever you do finally become more "public" with your "results," you may find yourselves sort of "shouted down" by a host of issues that would have been better dealt with individually, and woven into your final product.

I just reread "Of Heaven and Earth," subtitled "Reconciling Scientific Thought with LDS Theology," which is the most "public" attempt I can find at reconciliation, and conclude that it barely scratches the surface. One problem with those essays is that they are heavily weighted in favor of "scientific" truth.

Some of them attempt to go a long way to state some of the legitimate concerns of "nonbelievers," but, in my opinion, a much better product could be produced if there were give and take along the way.

The bottom line is that all treatments so far have come almost entirely from one side or the other, and have been ineffective at changing minds on either side.

4/05/2005 10:06:00 AM  

I understand your concern. I'm personally not to excited about having to fight over the validity of evolution for a number of reasons:

1) most objections, but not all, are motivated by doctrinal conflicts. If they see a doctrinal conflict they are more than welcome to comment on it, after all, thats what this blog is about.

2) if their issues with evolution are strictly scientific, they can go to the excellent resources we have posted on the site.

3) we don't want to get too side tracked and bogged down by having to justify and re-justify and re-re-justify everything we claim. A look at any post on evolution at nauvoo.com, timesandseasons and Millenial Star will show what I mean be that.

4) I'm very hesistant in reconciling a shady version of evolution when more evidence will likely show that our versions is false. Of course the same thing can be said for the scientists version, but if they are wrong this makes it all the more easy for us to accept it.

5) debating the validity of evolution rarely, if ever, changes somebodies mind on the subject. Both sides are at least somewhat acquainted with the others arguements and find them unconvincing. It really ends up being a shouting match at best.

Hence, I have opened this post to those who want to debunk evolution so they can have a voice without drowning out the voices of those who have other (more productive) things to say.

4/05/2005 10:39:00 AM  



<< Home