RNCSE 18 (4)

Articles available online are listed below.

NCSE Board Members: The Active Type

NCSE has received many offers for books and seminars that promise to help nonprofit organizations get members of their boards of directors to do something besides lending their names. We skip all that advice because we don't need it! NCSE is blessed with committed and caring board members who don't wait to be asked before they swing into action. Here's just a bit of what some of them have been up to.

John R Cole

Since retiring as NCSE editor, John has continued to serve as a contributing editor and book reviewer; he even returned as guest editor for our last issue. He has been first to find many of the news items and reprints you see in these pages. He has also
  • served as an advisor to many participants of the Internet "anticreationist" listserve who are coping with evolution/creation conflicts or seeking information on "creation science" arguments;
  • conducted research on possible investment opportunities as NCSE seeks to build an endowment fund;
  • written press releases on the activities of NCSE Board members and others working on NCSE issues;
  • continued building a library of evolution-related art from the 19th and early 20th centuries for use in NCSE publications.

Jack Friedman

Jack Friedman has a long career as a science educator and for the past 22 years has been involved with an annual conference for high school students. With a committee of 15 college and high school teachers he arranges a one-day meeting at which approximately 70 "experts" (college professors, physicians, and others) speak on a scientific topic that is of special interest to them. A brochure is prepared and mailed to schools located within an hour of the college campus where the conference will be held. Students pick the sessions they wish to attend and are grouped into classes of 25 which meet during four "periods" on the conference day. This is an enrichment opportunity for above-average high school students. And, he adds, "If any college or high school teacher wishes to put on such a conference, I would be pleased to offer advice and answer any questions that they may have. Our conference was awarded a state 'Program of Excellence'."

Michael McIlwrath

McIlwrath, the newest member of NCSE's board (see RNCSE 1997; 1 7(5):4-5), generously makes himself available to answer inquiries about case law affecting evolution and creation controversies. Besides having advised teachers who appealed to NCSE for help with problems arising from their commitment to evolution, he submitted a brief on NCSE's behalf in connection with the Tangipahoa, LA oral disclaimer case. He is still working on this case and will present oral arguments if the appeals court decides to hear further arguments (see Updates p 7). Meanwhile, Mcllwrath is helping NCSE staff explore the possibility of a special fund-raising event.

Kevin Padian

Kevin Padian, the current NCSE President, is a professor at the University of California's Berkeley campus, not far from NCSE's office. This proximity is a big help when NCSE staff want input from a board member. He has been taking advantage of a sabbatical this term to try to catch up on a lot of projects. Of these he comments, "Few of them are directly related to the creation-evolution issues at the moment. However, one hopes that by getting some science out to the public, issues can be clarified that are often misinterpreted or miscommunicated by anti-evolutionists. Primary among these, perhaps, is the origin of birds from small carnivorous dinosaurs. I have just finished two papers examining why this is a false controversy."

He has also worked with a colleague to write several papers summarizing and clarifying the evidence about bird origins for the public, including the February 1998 cover story of Scientific American and an article in Biological Reviews. (This topic is also covered in an entry in The Encyclopedia of Dinosaurs [Academic Press, 1997], a comprehensive and well-received book which Padian co-edited with Phil Currie.) He is also making progress on a variety of more technical projects, such as research on theropod dinosaur taxonomy and a paper on Darwin's view of classification which has just been accepted for publication in Systematic Biology.

Padian has always taken a strong interest in science education as well, actively contributing to development of science education standards in California. He has recently written chapters on natural selection for a book on evolution for teachers and on the origin of birds for an ornithology textbook. He has also given many public lectures at universities and for other organization, and been named a Distinguished Lecturer for 1999 by Sigma Xi, the Scientific Research Society of North America. Details of Sigma Xi's program selecting scientists, engineers, technologists, and pubhc policy analysts for a special lecture series are available in the November-December issue of American Scientist.

Then there are the things that get done for fun. Padian reports: "I also translated a very nice book by Philippe Taquet, who has been Director of the Institute of Paleontology and of the National Museums of Natural History in Paris, recounting over thirty years of his travels around the world in search of dinosaurs and their world. Dinosaur Impressions has just been published by Cambridge University Press, and it is a wonderful combination of paleontology, travelogue, history of science, and amusing stories. It provides a nicely Gallic perspective on our field and on science in general, and this is why I thought it would be fun to bring to an anglophonic audience."

Andrew J Petto

Does the name sound familiar? It should! Anj is the editor of Reports of NcSE. But that's not all. Anj constantly works for the improvement of evolution education, both in the academic arena and as a citizen. So far in 1998, Anj
  • worked with NCSE members and friends in Wisconsin to respond to a visit by Duane Gish and a "seminar" series entitled "Understanding the Times: A Worldview Weekend" and sponsored by Summit Ministries and the American Family Policy Institute;
  • worked with NCSE members for final acceptance of the Wisconsin Model Standards in Science (and social science) which contained a firm commitment to evolution in all areas of the sciences. (It was in the course of these efforts that Anj heard a supporter of "creation science" decry the influence of evolution on the children's book Horton Hatches The Egg (see RNCSE 1998; 18[1]: 24);
  • ran teacher workshops on "science as a way of knowing" (and evolution), including a half-day session on the Afar hominid fossil site with a featured speaker from the University of Wisconsin at Madison;
  • worked with a committee from the Society for the Study of Evolution to plan and carry out a workshop on teaching evolution for the SSE meetings in June 1999;
  • co-directed an invited workshop at a series of "Communicating Science" workshops at Hamilton College in upstate New York;
  • established a new course on "Science and Pseudoscience at the End of the 20th Century" at Philadelphia's University of the Arts;
  • completed an application for a Templeton grant for a new course called "Place in the Universe" which explores indigenous narratives and scientific explanations, discussing both cultural and cosmological implications;
  • and last but not least, since his move to Pennsylvania, Anj has begun building a whole new network of evolution supporters.

Elizabeth Stage

Elizabeth Stage is director of science for New Standards, a partnership of districts and states interested in standards-based reform. Last academic year she worked with a group of science educators from the Chicago Public Schools, led by NCSE member Melanie Wojtulewicz, Manager of Science Support. This group drafted programs of study for high school science courses based on the Chicago Academic Standards and Framework for Science, to be used as the basis for city-wide examinations. The Biology Program of Study has four areas of concentration, one of which is biological evolution.

This year Elizabeth is working with educators from New York City to assemble a collection of student work that shows teachers, students, and parents the quality of work that is expected at elementary, middle, and high school levels. Five themes have been selected for the life sciences: interdependence, structure and function, change over time, responding to changes, and reproduction and heredity.

Robert M West

"Mac" West contributes a vital link between NCSE and the world of "informal science" — museums, nature centers, and other science education facilities that are not school based. He reports that one of his most significant recent activities has been work on the "signature" film for the 3-D IMAX theater at the Smithsonian's National Museum of Natural History. The film, to be completed in 1999, features the Galapagos. West's consulting firm is working on educational materials to accompany the film.

He is also involved in the carly stages of planning the Space Science Initiative at the Denver Museum of Natural History, helping both to develop the storyline and to make sure that a full spectrum of educational opportunities are available. He comments, "An item of discussion always is ultimate origins, extraterrestrial life, and the statistical certainty that we are not alone."
NCSE Board Members: The Active Type
Molleen Matsumura
This version might differ slightly from the print publication.

Bibliolatry in the Grand Canyon

After his heroic pioneering voyage in 1869 down the Colorado River through the Grand Canyon, John Wesley Powell wrote
[T]he thought grew in to my mind that the canyons of this region would be a Book of Revelations in the rock-leaved bible of geology. The thought fructified and I determined to read the book.
Powell recognized that there are few places on the planet with such awe-inspiring beauty and with such dramatic and continuous vertical exposures, as can be seen in the colorful walls of the Grand Canyon through which the Colorado River flows for 450 km from Lee's Ferry to Lake Mead. The Canyon is more than 1600 m deep, and ranges from 6 to 30 km wide. Each year more than four million visitors visit Grand Canyon National Park in Arizona. There is perhaps no better place in all the world to appreciate the grandeur of geologic time (Calvin 1986; Redfern 1980).

However, bibliolatry has come to the Grand Canyon. The creationist textbook, Grand Canyon: Monument to Catastrophe (MTC), has challenged the accepted interpretations of geologic time and the geology of the Grand Canyon (Austin 1994). Heaton (1995) warns, "Many readers may find this book especially threatening because of its mix of scholarship and creationist dogma, targeted to a natural monument of great popularity." My aims in writing this article are to review creationist ideas on the geology of the Grand Canyon and to encourage members of the National Center for Science Education to review the field evidence for themselves by participating in the first NCSE "Creation/Evolution Grand Canyon Raft Trip", a float trip through the spectacular scenery and whitewater rapids of the Grand Canyon of Arizona, to be held in August 1999.

Stratigraphy of the Grand Canyon

Today the Grand Canyon is one of the best-known and most spectacular paradigms of stratigraphy. The canyon walls reveal exposures representing a slice of earth-history, spanning 1700 million years (Ma). Figure 1 shows the "classic" geologic section within the Grand Canyon as a block diagram, viewed toward the north-west. The sequence of strata exposed consists broadly of three major packets of rocks, respectively of Early Proterozoic, Late Proterozoic and Paleozoic age (Elston, Billingsley and Young 1989; Beus and Morales 1990). The oldest rocks are an Early Proterozoic (1700 Ma) crystalline basement (Vishnu Schists, intruded by Zoroaster Granites). Above these are Middle- to Late Proterozoic sedimentary and volcanic rocks, known as the Grand Canyon Supergroup, which were tilted and eroded before the deposition of the overlying Tapeats Sandstone of Cambrian age (
The Tapeats Sandstone of the Tonto Group is the oldest of the many sub-horizontal Paleozoic sedimentary formations which occur above the Precambrian rocks. Not so easily seen in Figure 1 is another major unconformity occurring between the Upper Cambrian Muav Limestone and the overlying Temple Butte Formation of Devonian age, so that Ordovician and Silurian strata, between 515 Ma and 385 Ma in age, are missing. The youngest rocks shown in Figure 1 are basalts which erupted from volcanoes on the Uinkaret region of the Colorado Plateau and poured down the steep cliffs of the north rim after the Grand Canyon was eroded. During the last 0.7 Ma more than 150 lava flows have cascaded down to form a series of lava dams in the inner gorge of the Grand Canyon which temporarily blocked the flow of the river (Dalrymple and Hamblin 1998).

The broad stratigraphic sequence of Grand Canyon rocks is well-established by numerous field observations in Powell's "bible of geology" (Spamer 1989). Powell was, of course, writing figuratively. His "bible" was the rock outcrops themselves. However, Figure 1 is taken from MTC (Austin 1994). Its contributors regard the King James version of the Bible as the true "bible of geology". At first sight, MTC resembles a well-illustrated, geological textbook, replete with maps, technical diagrams, and references to scientific literature. However its aim is to demonstrate unequivocally that the geology of the Grand Canyon is the product of creation week and Noah's flood, as determined by specific "literal" interpretations of the Book of Genesis.

Monument to Noah's Flood

The numerous modern scientific arguments against Noah's flood have recently been discussed by Isaak (1998) and Wise (1998) among many others. Austin (1994) has taken on the daunting task of using the spectacular geology of the Grand Canyon as an exemplar of a creationist world-view, despite numerous compelling arguments to the contrary. The result is a detailed and comprehensive text, covering a wide range of phenomena, which demonstrates familiarity with (if not acceptance of) much of the geological literature. The authors of MTC were asked to write a creationist field guidebook to the geology, biology, and human history of "the world's greatest natural wonder" at the undergraduate college level. However, the sections on geology and radiometric dating, written by Austin himself, are at a much more advanced, technical level. On the other hand, the chapter dealing with the atmosphere is very elementary. For example, the explanation of the physics of Noah's flood is so brief and qualitative as to be almost unintelligible to me. Some clue to the anticipated readership of MIC comes from the fact that Austin (1994) provides a lengthy glossary of technical (mostly geological) terms ranging from "abrasion" to "zonation". However explanations of other kinds of specialist "terms of art", with which MTC is replete, such as "sin" and "the fall of Adam", are singularly lacking. Evidently the authors of MTC anticipated that readers would be better trained in the ICR brand of religion than in their brand of geology.

The Genesis Story

To understand the creationist arguments propounded in MTC, it was necessary for me to refer frequently to the first eight chapters of Genesis. I found that the so-called "literal" interpretations at the ICR involve enormous embellishments of the basic story told in that book, involving mountain building, earthquakes, volcanic eruptions, and so on. According to Genesis 1:1-27, a creator-God is said to have formed by fiat the cosmos, the earth, and its biota, in 6 working days. Marine animals and birds appeared on Day 5 (Gen 1:20-1) and land animals, including one male and one female human, on Day 6 (Gen 1:24-7). This initial breeding pair of Homo sapiens and its progeny had life spans of several hundreds of years.

After a lapse of 1656 years (Austin, 1994:65) the creator-God re-appeared as a destroyer-God and caused a world-wide flood that extirpated all living things, except for a remnant which took refuge on a boat called "the Ark", built expressly for that purpose (Gen 6:11-6). The remnant consisted of a 600-year-old human (named Noah) and 7 family members, plus "two of every (other) sort of living thing.., male and female", and 7 breeding pairs of "clean beasts" and "fowls of the air" (Gen 6:18-20; 7:1-3). The flood lasted less than a year before the survivors left the ship for dry ground and migrated throughout the world (Gen 8:14-9).

Creationist Stratigraphy

The essence of MTC is contained in Chapter 4 which divides the strata of the Colorado Plateau into five major groups, according to the ICR reading of the Genesis story (Austin 1994:57-82). These are

Fifth division:
The youngest group of strata includes river gravels, lake sediments, and lava flows, formed after the erosion of the Grand Canyon, which in turn formed as Noah's flood ended.
Fourth division:
The Mesozoic strata represent erosion and deposition as floodwaters retreated.
Third division:
The Paleozoic strata comprising the Canyon's characteristic, horizontal strata formed in the early part of the flood.
Second division:
The Late Proterozoic Grand Canyon Supergroup, the older tilted stratified rocks below the 'Great Unconformity'. They formed during and after Day Three of creation week. The Great Unconformity formed by erosion during the onset of Noah's flood.
First division:
The Zoroaster Granite and the Vishnu Group, which formed during the first part of creation week.

Bringing Yellowstone to Grand Canyon

To evaluate and rebut the numerous specific creationist claims Austin presents, would require a book many times longer than MTC. Because Austin (1994:136) repeats the tired, erroneous argument that evolution violates the second law of thermodynamics, my book would begin with thermodynamics — a word frequently used by creationists to impress untrained people. MTC fails to mention that the creationist time scale violates the first and second laws of thermodynamics (Wise 1998). Austin (1994:69) indicates that on Day 3 of creation week, molten Zoroaster Granite was intruded into Vishnu Schist.

Ilg and others (1996:1160) estimate that the peak temperatures, associated with the emplacement of granites into the Granite Gorge Metamorphic Suite reached 650-725° C. Applying the laws of heat transfer to the cooling of igneous intrusions indicates that these features cool at rates varying between 30° and 250° C per million years, depending on the size and depth of the intrusion. This means it would take at least 2 million years for these igneous rocks to cool to the boiling point of water.

Even if these intrusions were too deep to present thermal problems during creation week, they are widely exposed in the inner gorge of Grand Canyon, only a "few thousand" ICR years later. Austin (1994) provides no clue to what thermal insulation, if any, organisms were using on Day 6 of creation which allowed them to survive the heat. Will our NCSE Creation/Evolution Grand Canyon Raft Trip encounter geysers or similar intense, explosive hydrothermal activity where the river enters the Upper Granite Gorge? Has bibliolatry brought Yellowstone National Park to Grand Canyon?

Attacking Uniformitarianism

A recurrent tactic in MTC is to state opposing arguments in such a way that they are more easily defeated. According to MTC, evolution depends on "the extreme generalization that only known, modern processes, operating at modern rates, formed strata (uniformitarianism) (Austin 1994:24, emphasis in the original). However, few geologists today would accept that only those geological processes observed happening today have operated in the past, and that they only did so at the rates currently observed. I believe that uniformitarianism, certainly in the extreme version formulated in MTC, is just like creationism; they are both concepts of respectable ancestry which have been superseded.

Perhaps the most blatant example of a straw man in MTC occurs in a discussion of the fate of the sediment removed from the Colorado Plateau when the Grand Canyon was eroded. Austin (1994:84) makes the valid points that the Colorado River in the Grand Canyon flows through the uplifted Colorado Plateau, rather than around it. Initiation of this uplift began in the eastern (Kaibab) part of the plateau due to flexing during the Laramide Orogeny (mountain-building episode) which geologists infer to have happened between 80 and 64 Ma ago. Austin (1994:87) cites data that the Colorado River carried approximately 153 million tons of sediment per year between 1926 and 1950. He then calculates that, at this rate, since the initiation of uplift in the last 70 Ma, the river should have transported a volume 1500 times greater than the volume of the Grand Canyon. Why, he asks, have geologists failed to locate anywhere near this amount of sediment downstream on the delta of the Colorado River?

To the uninitiated this argument might seem plausible, but a closer look reveals its flaws. First, even the most ardent uniformitarian should have qualms about extrapolating data from 25 years to 70 Ma. During this 70 Ma, there have been major realignments of the interactions between the North American and the Pacific tectonic plates, and dramatic changes in topography, climate and sea level. Second, this calculation is an inappropriate act because neither the Colorado River Delta nor the Grand Canyon, has been in existence for 70 Ma; both are no older than 4.5 Ma.

The Colorado River Delta partially fills the depression known as the Salton Trough, an extension of the tectonic regime of the Gulf of California (Elders and others 1972). It was formerly filled by the waters of the gulf, as shown by the widespread occurrence of the marine sediments of the Imperial Formation (Lonsdale 1989). Drilling for geothermal resources confirms that, along the axis of the trough, these marine rocks are covered by younger deltaic sediments more than 4 km thick. This scenario is consistent with the dating of the onset of erosion by the Colorado River in the western part of the Grand Canyon. Luchitta (1990) shows that this occurred in Pliocene times, 5 to 3.8 Ma ago. Prior to that time the lower Colorado River system, as we know it today, did not exist. Both the ages and the volumes of the canyon and the delta are quite consistent. The Delta contains roughly 270 000 cubic kilometers of Pliocene to Recent sediments, equivalent to a canyon measuring 450 X 37.S X 1.6 km deep — a volume somewhat larger than the Grand Canyon proper.

Ignoring the Geologic Time Scale

A major omission in MTC is any discussion of the great synthesis of worldwide geologic observations known as the Geologic Time Scale. Wise (1998) pointed out that the creationist time scale ignores the countless worldwide geological studies which show that, on all continents, the same general sequence of sedimentary rocks occurs, and that the major and minor divisions in this sequence are characterized by the specific assemblages of fossils they contain. This overall scheme was essentially completed before 18S9 when Darwin published his On the Origin of Species by Means of Natural Selection. No assumptions of organic evolution were made in deriving the geologic column or in using fossils for correlation of strata from continent to continent. However, the eras and periods of the geologic time scale, with which we divide geologic time, reflect the dramatic changes which have occurred in the history of life on earth recorded in the rocks (Gould 1994). Because of these changes, the fossil assemblages found in each geologic system are distinct, permitting us to make worldwide stratigraphic correlations. Today such correlations are also made using non-paleontological criteria, such as radiometric dating, and sequences of magnetic reversals and of light stable isotope ratios, particularly carbon isotopes (Bowring and Erwin 1998).

Sequences of strata occur everywhere in the same order, with minor exceptions due to tectonic disturbances. However, in many places (the Grand Canyon is an example), parts of the sequence are missing, due either to non-deposition, or to erosion subsequent to deposition. However, in more than a dozen deep sedimentary basins throughout the world, the whole sequence of sedimentary rocks bearing fossils is essentially complete. During the last twenty years, stratigraphic correlation of these sedimentary rocks has been buttressed by the use of "sequence-stratigraphy", developed largely by major oil companies. The presence of major "unconformities" or ancient erosional surfaces can be used to correlate rock units over wide areas. Many of these erosional surfaces are of global extent because they were formed during periods of worldwide lowering of sea level due to extensive glaciations. The remarkable concordance obtained between these independent methods gives powerful support to the thesis that the Geologic Time Scale records 3.8 billion years of earth history (the age of the oldest dated crustal rocks) and that the sequence of fossils these rocks contain is the record of organic evolution.

Discussion of these issues is omitted in MTC. For example Chapter 7, entitled "Fossils of Grand Canyon", presents some of the weakest arguments for the creationist position. The authors make the astounding claim that "[i]t is not clear whether the order of appearance of organisms in Grand Canyon, or anywhere on Earth, for that matter, is necessarily any different than a random order which a flood might produce" (Austin 1994:147). Before creationists recommend that oil companies shut down their Departments of Stratigraphic Paleontology, they should decide whether they prefer to walk or to drive.

The Problem of Space for Fossils

Another problem in MTC is where to put all the organisms living in the world before the flood. Geologists infer that the organisms in the fossil record accumulated during a period longer than 500 Ma, but according to MTC, all these organisms were alive during the 1656 years between the creation and the Noachian flood. If we take the total biomass represented by fossils when alive, and divide by the number of years during which that biomass is believed to have accumulated, the amount of living matter would have to be over 30,000 times greater in the creationist's pre-flood world than in the geologist's evolutionary world. Not only would the flora and fauna have to be incredibly more abundant in the pre-flood world but it also would have to be incredibly more diverse than at present; all extinct organisms would have to have been present at roughly the same time. Were there no limits to the carrying capacity of the ecological niches available to these organisms in the pre-flood world?

To have accumulated in that time from the original breeding pairs would require an enormous reproductive success and survival rate by the founding stock. If the human population before the flood world grew at the same rate, there would have to have been 1.8 X 1015 people in Noah's time — about 300,000 times the world population of 5.9 billion humans alive today. After 1656 years of the inevitable environmental degradation which would accompany such a prodigious human population explosion, I wonder that there was enough wood left for Noah to build an ark!

Another point not explained in MTC is the paucity of fossils in the Proterozoic sedimentary rocks. Austin (1994:57) claims that the uppermost strata of the Proterozoic Grand Canyon Supergroup "represent normal sedimentation in the post-Creation, but pre-flood ocean". Considering the hyper-productivity of the pre-flood biosphere required by the creationists' model, one would expect that these rocks would be the most highly fossiliferous on the planet and that the Proterozoic flora and fauna would be rich and diverse, including representatives of both extinct and extant taxa. Instead we see a very low abundance of fossils consisting only of unicellular organisms, cyanobacteria and stromatolites (algal mats). There are no remains of coral reefs, trilobites, ichthyosaurs, whales, nor shipwrecks in Proterozoic marine sedimentary rocks.

Original Creationist Research

The scientific data and observations presented in MTC are almost entirely re-interpretation and attempted rebuttal of published main-stream science. But what of original creationist research? The appendix of MTC lists 18 "Questions for Discussion and Study". The last of these reads, "What are four research projects creationists have conducted on Grand Canyon?" A careful reading of MTC reveals that the author of this question expects students to be diligent. In fact, I was able to find only four examples of creationist research which could be cited, plus one which the authors of MTC admit is dubious.

Precambrian Pollen

This latter example is instructive because it shows that even when "creation science" is refuted there is an urge to cling to "evidence" favorable to the cause (Austin 1994:137). Burdick (1966) claimed to have isolated pollens of pine, juniper and Mormon tea in samples of the Proterozoic Hakatai Shales in the Grand Canyon, rocks much older than the first appearance of vascular plants in the geologic record. When later, more comprehensive and careful studies failed to reproduce these results, it was concluded that Burdick's work was simply a case of contamination by modern pollens (Chadwick 1981). MTC still leaves the door open by concluding, "The possibility of pollen in Precambrian rocks, no doubt, will remain controversial among creationists."


Original research by a creationist in Grand Canyon first appears in MTC on page 26 where Austin (1994) reports actual new data. In some places in the Mississippian Redwall Limestone, fossils of orthocone, chambered nautiloids (marine mollusks differing from modern nautilus by having straight, rather than coiled, shells) are abundant. Austin measured the orientation of 12 examples of these nautiloids in a single outcrop and showed that 10 of them are aligned with their long axes within an arc spanning 90°. He concludes that this preferred orientation indicates that the nautiloids received their alignments when dead, as lime mud was moved by water currents. He concludes that this is consistent with the flood hypothesis rather than "the uniformitarian notion that fine-grained limestone beds of Grand Canyon usually accumulated... in a calm and placid sea" (Austin 1994:28).

Modern Squirrels

A second example in MTC of original data by a creationist concerns modern populations of tassel-eared squirrels (Sciurus aberti; Austin 1994:174). Earlier work had suggested that two distinct races of these squirrels have evolved on the plateaus north and south of the Grand Canyon due to geographic isolation. However, after examining 94 museum specimens, Meyer (1988) concluded that the two groups contain individuals showing close enough resemblance so that, for all practical purposes they form one continuous population. Thus, in Meyer's opinion, although the two groups are geographically isolated, divergent evolution is not demonstrated by Sciurus aberti.

Desert Dunes and Fossil Footprints

The argument for a flood origin for Grand Canyon rocks is particularly weak in the case of the Permian Coconino Sandstone Formation which consists of very pure sandstones with prominent sets of cross-stratification dipping at high angles. This formation is regarded as being the product of extensive, Sahara-like sand dunes (McKee 1979). The sandstone consists of fine-grained, well-sorted, well-rounded, frosted and pitted grains, composed almost entirely of quartz — features that are characteristic of the effects of grain-to-grain impacts and of winnowing during wind-borne sediment transport. Other evidence which indicates that the Coconino Sandstone was not formed in a catastrophic flood is the presence of raindrop impressions and of abundant, well-preserved animal tracks (McKee 1979). Of course, MTC does not accept the view that the Coconino is an extensive desert dune deposit and claims that the dunes are actually submarine sand waves (Austin 1994:33).

The animal tracks in the Coconino Sandstone are consistently preserved on steep, upwind, slopes of the fossil dunes rather than on the lee sides, where they would be destroyed by avalanching of dry sand. They are interpreted as being produced by invertebrates (similar to modern isopods, scorpions, millipedes, or spiders) and by diverse four- or five-toed vertebrates (Middleton and others 1990). The nature of the animals responsible can only be inferred from the trackways, as body fossils have not been recognized in the Coconino Sandstone. This leads us to the third example of original creationist research, a study which re-interprets these track-ways from the creationist viewpoint.

This study by Brand and Tang (1991) included experiments on the track-making abilities of western newts walking on sand under 4 cm of flowing water in an aquarium tank. They report that some unusual tracks in the Coconino start and end abruptly and have individual prints oriented obliquely to the general trend of the trackway. By analogy with their tank experiments, they infer that such tracks were formed by amphibians buoyantly supported in flowing water. They conclude that these features, "point to the subaqueous deposition for at least part of the Coconino Sandstone" (Brand and Tang 1991: 1204).

On the other hand, as part of an extensive review of animal trackways, Lockley and Hunt (1995) decided that the vertebrate trackways in the Coconino Sandstone were made by mammal-like reptiles (called caseids) rather than by amphibians. Furthermore they record trackways made by animals moving with loping, trotting, or galloping gaits, most often up slope, but occasionally horizontally or obliquely to the slope. They also point to the prob1cm of the many invertebrate traces. It is difficult to imagine millipedes, scorpions and spiders making prolific underwater tracks. Besides, the geological evidence for the eolian origin of the Coconino Sandstone is compelling.

Radioisotope Dating

Radiometric dating of rocks and minerals works by modeling the time elapsed since the formation of a sample by measuring the ratio of the abundance of a parent isotope to the abundance of its daughter isotope produced by radioactive decay. The rate at which a radioactive parent isotope decays to its daughter isotope is well known. To correct for the ratio of this isotope pair present at the time of formation of the sample, we use the so-called "isochron" method (Dalrymple 1991). This requires that we analyze a number of samples that geologic criteria indicate were cogenic (that is, they formed at the same time) and from a medium which had a common, uniform ratio of the two isotopes. A typical example would be a sample of rocks and minerals extracted from a single volcanic extrusion with a common initial isotope ratio acquired from that lava. For samples which are cogenetic, the isotope ratios of parent to daughter, normalized to a non-radiogenic isotope of the daughter element, plot on a straight line, termed an isochron. This is because, in each sample, the parent isotope decreases and the daughter isotope increases due to radioactive decay. Having obtained an isochron we can determine the initial parent to daughter isotope ratio and correct for it in calculating the time elapsed since the formation of the rock.
The fourth example of original creationist research is important enough to have been awarded a chapter to itself in MTC (Austin 1994, Chapter 6). It takes head-on one of the most difficult issues for young-earth creationists — the problem of radiometric age measurements. The chapter begins with an explanation of how radioactive isotope ratios are used in dating and of the assumptions inherent in the technique. This makes it all the more puzzling when Austin perversely proceeds to misapply the method by violating these assumptions. To help understand the nature of this perversity, a short review of radioactive isotope dating methods might be helpful for some readers (see sidebar right).

In Chapter 6 of MTC, Austin describes what he claims was a systematic research project to test isochron radiometric dating using rubidium and strontium isotopes. The rubidium isotope 87Rb decays to its daughter strontium 87Sr, whereas 86Sr is the common non-radiogenic isotope of strontium. Austin reports Rb/Sr data from whole-rock samples of the Pleistocene volcanoes on the Uinkaret Plateau, collected from five different basalt flows.

The 5 data points fall on a reasonably straight line which he claims defines an isochron giving a common age of 1300 Ma years (Austin 1994:124). For Proterozoic rocks, he plotted an isochron giving a common age of 1070 Ma (Austin 1994:122). He triumphantly points out that it is impossible for these rocks, which are clearly older than the formation of the Grand Canyon, to be 270 Ma years younger than the Pleistocene basalts, which certainly formed after the canyon was eroded. This leads him to challenge the basic assumptions of the radioactive dating by asking, "Has any Grand Canyon rock been successfully dated?" (Austin 1994:129).

In other locations there are tens of thousands of radiometric dates which are consistent with the relative stratigraphic positions of the rocks dated (Dalrymple 1991). Why should Grand Canyon be different? In answer to Austin's rhetorical question we can point to two recent studies. In their work on the oldest rocks of the Grand Canyon, Ilg and others (1996) used 238U/206Pb ratios in individual crystals of zircon and monazite to derive a detailed chronology for the Early Proterozoic metamorphic and igneous crystalline rocks. Two different units of the Granite Gorge Metamorphic Suite gave ages of 1750 and 1742 Ma. Two different members of the Zoroaster Plutonic Complex, which intrude the Metamorphic Suite, gave ages of 1740-1710 Ma and 1700-1660 Ma. These ages are completely consistent with the stratigraphic positions and crosscutting relations of these rocks. The Late Proterozoic Rb/Sr isochron age of 1070 Ma for the Cardenas Basalt reported in Austin is also consistent with its stratigraphic position.

The 1300 Ma age for the Pleistocene basalts determined by Austin from his data is clearly inconsistent with more recent work of Dalrymple and Hamblin (1998). These workers measured 40K/40Ar isotopic ratios in 65 whole rock samples from the lavas which flowed into the canyon and temporarily dammed the Colorado River at least 13 different times. The ages obtained lie in the range 0.684 Ma to 0.443 Ma. With few exceptions, the relative ages of the 65 samples analyzed are in the same order as that in which the lavas erupted, determined by superposition. These exceptions appear to have been caused either by the presence of carbonate, which interferes with the clean-up process during Ar extraction, or by the presence of "dunite xenoliths" which contribute unknown and varying amounts of inherited 40Ar (Dalrymple and Hamblin 1998). Dunite xenoliths are remnants of unmelted older parent material from which the basalt magma (melt) was originally formed and so are much older than the lava flows.

Austin's "test" of Rb/Sr isochron dating of these same Pleistocene basalts has been examined and thoroughly refuted by Stassen (1997). In an earlier publication Austin (1988) used data selectively from Leeman (1975) to plot a seemingly reliable Rb/Sr isochron which gave an apparent age of 1500 Ma for these Pleistocene lavas. In a section of his paper headed "Fictitious Isochron Ages", Austin (1988) noted that such "false Rb/Sr isochrons" have been well documented in the scientific literature. Citing this literature, Austin (1988) explained that false isochrons are caused by isotopes such as 87Sr being "inherited from the molten material's source at great depth in the earth". Stassen (1997b) points Out that this statement indicates that Austin knew he would get a false isochron long before collecting his own samples from the Western Grand Canyon for Rb/Sr analysis. The study of Pleistocene basalts described by Austin in MTC, rather than being a true test of Rb/Sr isochron dating, was an exercise in reproducing a previously-determined false isochron.


My copy of Webster's dictionary defines bibliolatry as, "absolute dependence on a group of sacred writings as infallible". Where others have read the "rock-leaved bible of geology", the authors of GTC bring a different bibliolatry to the Grand Canyon. The book presents a more detailed argument than any previous creationist publication on geology. The crux of the book is a lengthy and detailed, but ultimately failed, attempt to rebut published accounts of the geology, paleontology, and dating of the strata of Grand Canyon and to present re-interpretations consistent with the Genesis story. Such reinterpretations are buttressed by some original creationist research. However, a case of contamination of pollen samples, 12 oriented nautiloids, the tale of 94 squirrel skins, some experiments with tracks made by newts in an aquarium, and wilful misinterpretation of radiometric dates based on five Rb/Sr isotopic ratios scarcely constitute a deluge of new compelling evidence for the flood of Noah.

In yet another sense I found it difficult to understand for whom the book is intended. Creationists relying on unquestioning faith do not need physical evidence; the rest of us, particularly those more technically trained, are likely to find that the close examination of the evidence presented in MTC leads us even further away from bibliolatry. In presenting their strict, religiously-based, interpretation of such a well-studied and spectacular region as the Grand Canyon — an interpretation which is in stark contrast to that of main-stream geologists — the authors apparently willingly accept the risk of bringing their fundamentalist religion into disrepute. Presumably their expectations were otherwise. Decide for yourself by joining us in the Grand Canyon on the first NCSE Creation/Evolution Grand Canyon Raft Trip! (See p.25 for details!)

References Cited

Austin SA. Grand canyon lava flows: a survey of isotope dating methods. Impact 1988; #178. Available at htpp://www.icr.org/pubs/imp/imp-178.htm, accessed 7/29/1998.

Austin SA. (editor). Grand Canyon: Monument to Catastrophe. Santee (CA): Institute for Creation Research, 1994.

Beus SS, Morales M. (editors). Grand Canyon Geology. New York: Oxford University Press, 1990.

Bowring SA, Erwin DH. A new look at evolutionary rates in deep time: Uniting paleontology and high-precision geochronology GSA Today 1998; 8(9): 1-8.

Brand LR, Tang T. Fossil vertebrate footprints in the Coconino sandstone (Permian) of Northern Arizona: Evidence for underwater origin. Geology 1991; 19(12): 1201-4.

Burdick CL. Microflora of the Grand Canyon. Creation Research Quarterly 1966; 3: 38-50.

Calvin WH. The River that Flows Uphill: The Journey from the Big Bang to the Big Brain. New York: Macmillan Publishing Co, 1986.

Chadwick AV. Precambrian pollen in the Grand Canyon — A reexamination. Origins 1981; 8:7-12.

Dalrymple GB. The Age of the Earth. Stanford (CA): Stanford University Press, 1991.

Dalrymple GB, Hamblin WK. K-Ar ages of Pleistocene lava dams in the Grand Canyon in Arizona. Proceedings of the National Academy of Sciences (US) 1998; 95: 9744-9.

Elders WA, Rex RW, Meidav T, Robinson PT, Biehler S. Crustal spreading in Southern California. Science 1972;178: 15-24.

Elston DP, Billingsley GH, Young RA (editors). Geology of Grand Canyon, Northern Arizona (with Colorado River Guides). Washington (DC): American Geophysical Union, 1989.

Gould SJ. The evolution of life on earth. Scientific American 1994; 271(4): 84-91.

Heaton TH. A young Grand Canyon? Skeptical Inquirer 1995: 19(3): 33-7.

Ilg BR, Karlstrom KE, Hawkins DP, Williams ML. Tectonic evolution of Paleoproterozoic rocks in the Grand Canyon: Insights into middle-crustal processes. Geological Society of America Bulletin 1996; 108(9):1149-66.

Isaak M. Problems with a global flood. The Talk.Origins Archive 1998, Second Edition available at http://www.TalkOrigins.org Accessed Sept. 2, 1998.

Leeman WP. Late Cenozoic alkali-rich basalt from the Western Grand Canyon area, Utah and Arizona: Isotopic composition of strontium. Geological Society of America Bulletin 1975; 85:1691-6.

Lockley M, Hunt AP. Dinosaur Tracks. New York: Columbia University Press, 1995.

Lonsdale P. Geology and tectonic history of the Gulf of California, in Winterer EL, Hussong DM, Decker RW (editors), The Eastern Pacific Ocean and Hawaii. Boulder (CO): Geological Society of America, 1988. pp 499-521.

Luchitta I. History of the Grand Canyon and the Colorado River in Arizona. in Beus SS, Morales M (editors). Grand Canyon Geology. New York: Oxford University Press, 1990. pp 331-2.

McKee ED. A study of global sand seas: Ancient sandstones considered to be Eolian. US Geological Survey Professional Paper Nr. 1052. Reston (V.A): US Geological Survey, 1979.

Meyer JR. Origin of the Kaibab squirrel. Creation Research Quarterly 1985;22: 68-78.

Middleton LT. Elliot DK, Morales M. Coconino Sandstone, in Beus SS, Morales M. (editors). Grand Canyon Geology. New York: Oxford University Press, 1990; Chapter 10.

Powell JW. Exploration of the Colorado River of the West and its Tributaries. Explored in 1869, 1870, 1871, and 1872, under the Direction of the Secretary of the Smithsonian Institution. Washington (DC): US Government Printing Office, 1875.

Redfern R. Corridors of Time. New York: NY Times Books, Inc, 1980.

Spamer EE. The development of geological studies in the Grand Canyon. Tyronia, Miscellaneous Publications of the Department of Malacology. Academy of Sciences of Philadelphia, 1989:17.

Stassen C. A criticism of the ICR's Grand Canyon Dating Project. The Talk.Origins Archive 1997(b) available at http://www.talkorigins.org/faqs/icr-science.html accessed 9/29/1998.

Appendix 1

The Laws of Thermodynamics

The laws of thermodynamics describe the internal energy in a system and how that energy may be exchanged between the system and its surroundings. The variables that describe the internal state of a system concern the total energy of molecules making up that system in terms of temperature, gas pressure, and volume. The first law of thermodynamics describes how work and heat change the internal state of the system. The internal energy of a system can be lowered by converting heat to work, just as the internal energy can be raised by converting work to heat. The "conservation" of energy refers to the fact that internal energy can and does change, and we can use the relationship between heat and work to estimate the speed and intensity of the change.

The second law of thermodynamics describes a preferred direction in the transfer of energy — from a state of higher to lower internal energy. This means that, if the energy of the surroundings is lower than that within a system, then that system will gradually exchange energy with its surroundings until the energy states match. The second law also tells us that the conversion of heat to work is not absolute; there is always some heat that dissipates in the process, and this causes the total energy available to the system to decrease. The second law also tells us that the conversion of heat to work is not absolute; there is always some heat that dissipates in the process, and this causes the total energy available to the system to decrease. The second law also tells us that the "tendency to entropy" (or disorder) that seems to be inevitable can be reversed simply by adding energy to the system from another source; volcanic eruptions of solar radiation are two of the more common sources of this added energy on earth.

[From BW Tillery. Physical Science, 4th edition. New York: WCB/McGraw-Hill. 1999; compiled by AJ Petto]


Getting to Know Rocks and Minerals

Mineral. A mineral is generally a solid, inorganic compound. The atomic structures, chemical compositions, and physical properties vary somewhat, but, for example, all quartz crystals have the same properties whether in sandstone or in granite or in lava.

Rock. A rock is a collection or aggregation of a number of different minerals fused together in certain combinations. Rock is classified into 1 of 3 groups depending on how it is formed.

igneous. Igneous rock is formed as magma cools. This type of rock may be produced as lava flows cool on the surface (or the ocean floor) or as the molten rock forces itself between other rock in the earth's crust.

sedimentary. Sedimentary rock is formed as mineral particles are deposited in layers in lakes, river deltas, dunes, or seabeds. The particles can be transported by glaciers, wind, or water.

metamorphic. Metamorphic rock is formed as igneous or sedimentary rocks are subjected to intense pressure and/or heat. This causes the structure and the properties of the rock to be changed. If enough heat and pressure are applied, the rock melts to become magma again.

The Rock cycle. The rock cycle describes the various stages in the building and remodeling of the rocks which make up the earth. For convenience the cycle starts with molten magma below the earth's crust. The magma slowly rises to the surface on currents like those we can see in boiling water. When it invades the solid crust or reaches the surface, the magma cools and forms solid rock. Movements in the earth's crust and erosion by ice, wind, and water cause minerals to be worn out of the rock and cause deeper rock to be exposed to the surface. These minerals are transported and deposited in layered sediments which solidify into rock. The intense pressure and/or temperature applied to sedimentary and igneous rock by geological processes transforms it into metamorphic rock. Higher pressure and temperature can transform any solid rock back into molten magma to complete the cycle.

Basalt. A fine-grained igneous rock — the most abundant type of lava.

Dikes. Small intrusions by molten rock.

Gabbro. A course-grained rock common in plutonic intrusions poor in quartz and silica.

Gneiss. A banded metamorphic rock rich in quartz and feldspar and formed under high temperature and pressure.

Intrusions. Cooled molten rock which has forced itself between other cooled rocks in the earth's crust.

Plutons. Intrusions by molten rock which form large masses.

Schists. A metamorphic rock rich in feldspar, quartz, and mica formed under moderate pressure and low to moderate temperature.

Shale. A fine-grained sedimentary rock rich in clay minerals and often containing fossils.

[From C Pellant. Rocks and Minerals. New York: Dorling Kindersley, Inc. 1992; compiled by AJ Petto.]
Bibliolatry in the Grand Canyon
Wilfred A Elders
This version might differ slightly from the print publication.

Evolution as a Heuristic

"If you will not let me treat the Art of Discovery as a kind of Logic, I must make a new name for it. Heuristic, for example" (William Whewell, quoted in Todhunter, 1970).
Creationists continue to claim scientific validity for their version of "scientific creationism" and to demand its admission to the science classrooms of the nation's public schools. If both "models" are fairly presented, they say, students would overwhelmingly prefer the creation model over the evolutionary view.

This may be good propaganda, but the claim ignores the historical fact that we had just such a choice once before, and we chose evolution. What the creationists overlook is that before the publication of Origin of Species nearly everyone was a creationist — scientist and layman alike — and that a few years later, nearly everyone, scientist and layman alike, had become an evolutionist.

One of the major factors in this rapid transformation was the recognition that evolution provided a more rational way of organizing natural history than the traditional view of providential design. In particular, as a whole new way of looking at nature, it generated vast new areas for investigation not previously perceived. This heuristic, or exploratory, advantage of evolution has been little used in current debates, yet evolution continues to be an excellent heuristic, while creationism has no exploratory consequences at all. It is my purpose in outlining the heuristic argument at Darwin's time to provide additional perspective on today's debates.

The doctrine of special creation that dominated biological thinking in the century before Darwin was not basically different from so-called "scientific creationism" today. Both were derivatives of the faith in the absolute validity of the Genesis account of creation. But if one has belief in a final truth, then there is no need for further investigation, and this is the end of science. Darwin and his colleagues recognized this barrier to the search for the enlargement of human understanding of nature.

The capacity of evolutionary thinking to elucidate the facts is nowhere more effectively demonstrated than in the Origin itself where page after page is filled with observations demonstrating patterns and interrelationships of facts that could hardly have been noted without the guiding hypothesis of evolution. In the final chapter Darwin makes clear the heuristic function of his theory which will give a new sense of order to what it already known, and open vast prospects for new understanding.

[W]hen we regard every production of nature as one which has had a history; when we contemplate every complex structure and instinct as the summing up of many contrivances, and each useful to the possessor... when we thus view each organic being, how far more interesting... will the study of natural history become!

A grand and almost untrodden field of inquiry will be opened, on the causes and laws of variation, on correlation of growth, on the effects of use and disuse, on the direct action of external condition, and so forth. The study of domestic productions will rise immensely in value. A new variety raised by man will be a far more important and interesting subject for study than one more species added to the infinitude of already recorded species. Our classifications will come to be, as far as they can be so made, genealogies; and will then truly give what may be called the plan of creation (C Darwin, p 486).
Rules of classification, he added, will become simpler, embryology will reveal structure, geographical distribution will be illuminated by increased geological knowledge, changes of climate, and so on. All these and many more areas of human curiosity will be freshly perceived through the perspective of descent with modification.

In addition to listing the benefits of his evolutionary perspective, Darwin also noted the negative effects of the prevailing doctrine of special creation. For too many years, naturalists had viewed species as specially created to occupy the niches into which they are clearly adapted. But this traditional view could now be seen for what it was, a way "to hide our ignorance under such expressions as the 'plan of creation', 'unity of design', &c., and to think that we give an explanation when we only restate a fact." And the sterility of such views is further disguised by assuming a "reverent silence" instead of seeking causal explanations (C Darwin, p 482-3). It is, after all, the office of science to investigate nature, not merely to admire it.

Darwin's earliest confidant, botanist Joseph Hooker, resisted for 14 years Darwin's arguments for descent with modification. It was only while Darwin was rapidly writing Origin that Hooker indicated that he was going to organize his "Essay on Australian Flora" according to the new views. Darwin was delighted and wrote to Hooker, July 13, 1838 emphasizing the opportunities the theory created.
You cannot imagine how pleased I am that the notion of Natural Selection has acted as a purgative on your bowels of immutability. Whenever naturalists can look on species changing as certain, what a magnificent field will be open — on all the lines of variation — on the genealogy of all living being — in their lines of migration, &c., &c. (F Darwin 1837:485).
And Hooker in turn expresses the heuristic advantages of evolu-tion when explaining his intentions to his botanical colleague William H Harvey.
What I shall try to do is, to harmonize the facts with the newest doctrines, not because they are the truest, but because they do give you room to reason and reflect at present, and hopes for the future, whereas the old stick-in-the-mud doctrines of absolute creations, multiple creations... are all used up, they are so many stops to further enquiry; if they are admitted as truths, why there is an end of the whole matter, and It is no use hoping ever to get to any rational explanation of origin or dispersion of species — so I hate them (Huxley 1918:481-2).
The deadening effects of a strong commitment to special creation is nowhere more clearly illustrated than by Adam Sedgwick in his 1860 review of Origin.
Change the conditions of life, he admits, and old species would die out, and new species might have room to come in and flourish. But how, and by what causation? I say by creation. But, what do I mean by creation? I reply, the operation of a power quite beyond the powers of a pigeon fancier, a cross-breeder, or hybridizer; a power I cannot imitate or comprehend; but in which I can believe. (Quoted by Hull 1973:161).
By declaring his faith in a "power I cannot imitate or comprehend", Sedgwick has set the problem of species outside the scope of human inquiry, and in Hooker's words, "there is an end of the whole matter."

In contrast to the stultifying effects of creationism, Thomas Huxley saw in Darwin's work the fulfillment of the highest aims of science and humanity itself.
The known is finite, the unknown infinite; intellectually we stand on an islet in the midst of an illimitable ocean of inexplicability. Our business in every generation is to reclaim a little more land, to add something to the extent and the solidity of our possessions. And even a cursory glance at the history of the biological sciences during the last quarter of a century is sufficient to justify the assertion, that the most potent instrument for the extension of the realm of natural knowledge which had come into men's hands, since the publication of Newton's "Principia," is Darwin's "Origin of Species" (F Darwin 1887: 557).
An additional century has not altered the validity of Huxley's assessment, and the creationism so vigorously rejected then still has no place in the intellectual toolbox of science today.


A good scientific theory provides not only a rational organization of factual information, essential for effective pedagogy, but also stimulates questions that lead to further investigations, new factual knowledge of nature, and modification and expansion of the theory. Evolution continues to do this even as it has been modified. Creationism has NO exploratory consequence and thus has no justifiable place in science classrooms.


If this heuristic function of evolution and all scientific theories can be conveyed to the general public, surely evolution will be generally supported as good science, and creationism recognized as not science at all. To meet this challenge we need to develop and present a series of specific examples of how evolutionary thought has led directly to the discovery of valuable knowledge in the biological sciences. Examples from agriculture and medicine would perhaps be most persuasive to those who determine classroom curricula: school boards, school administrators, teachers, and parents. All of us who support evolution in science education should take up this challenge.


Darwin C. On the Origin of Species: A fac-simile of the first edition. NY: Atheneum, 1967.

Darwin E (editor). The Life and Letters of Charles Darwin. Vol 1. NY: D Appleton and Company, 1887.

Hull DL. Darwin and His Critics: The Reception of Darwin's theory of Evolution by the Scientific Community. Cambridge (MA): Harvard University Press, 1973.

Huxley L. Life and Letters of sir Joseph Dalton Hooker. New York: Appleton, 1918.

Todhunter I. William Whewell, D.D., master of Trinity College, Cambridge; An account of his writings with selections from his literary and scientific correspondence. New York: Johnson Reprint Corp, 1970.

About the Author(s): 
Dr Robert Siegfried
2206 West Lawn Ave
Madison WI 53711-1952
Evolution as a Heuristic
Robert Siegfried
This version might differ slightly from the print publication.