It has been more than twelve years since we (Collins 1988, 1997b; Hunt and others 1992) discussed Robert Gentry’s hypothesis proposing that polonium (Po) halos and granite were created nearly instantaneously on Day Three of the Genesis Week (Gen 1:9–10; Gentry 1965, 1970, 1974, 1983, 1988). It is worth examining new information pertinent to the origin of polonium halos. Gentry points out that most granite petrologists believe that all granite bodies of large size are formed deep in the earth’s crust from magma (molten rock) and that as much as 5 million years are required for this magma to be cooled sufficiently for biotite mica to begin to crystallize (see sidebar on p 13 for descriptions of these minerals).
Polonium halos occur in biotite in granites of supposed magmatic origin, and the half-lives of the polonium (Po) isotopes are short (218Po, 3.05 minutes; 214Po, microseconds; and 210Po, 140 days). Gentry claims, therefore, that no matter how much original polonium may have been present in the granite magma, all would have decayed to stable lead (206Pb) in 5 million years, long before the biotite in which polonium halos are found could have formed. He asserts on that basis that polonium halos can be used to support the literal interpretation of the Bible that granite in the earth was created during Day Three of the Genesis Week and not over a period of ~4.6 billion years (Dalrymple 1991). This rapid formation of granite during Day Three and supposed disappearance of polonium isotopes during 5 million years are ideas that are also promoted by Snelling (2008a, 2008b). [Thomas A Baillieul’s detailed summary and critique of Gentry’s views begins on p 17.]
Gentry and Snelling’s claims are without validity (Collins 2008). These creationists ignore the fact that uranium in the original magma would be continuously supplying polonium isotopes during the 5 million years of cooling. The problem is not the disappearance of polonium through 5 million years, as Gentry and Snelling suggest, but the inability of polonium ions produced during this time to migrate from scattered uranium atoms in very viscous magma to precipitate as polonium atoms in a localized place in a growing biotite crystal lattice so that polonium halos can form. The question to ask, therefore, is: how has it been possible for uranium to concentrate in local sources so that polonium, which is derived from the decay of this uranium, could nucleate in growing crystals of biotite or fluorite? There are two possible mechanisms to make this concentration happen. The first is by the formation of either vein-dikes or pegmatites containing uranium minerals that are associated with chemical replacement processes (metasomatism). The second is by the formation of pegmatites containing uranium minerals that result from magmatic processes. Both mechanisms are examined in this article.
|FIGURE 1. Myrmekite (center; white vermicules [quartz]; black [plagioclase feldspar]) adjacent to potassium feldspar with grid twinning (bottom; black and white) with cross-polarized light.|
Collins found that in many places where poloniumhalo- bearing biotite and fluorite crystals are present, the adjacent granitic rocks were microfractured and contained myrmekite (the intergrowth of plagioclase and vermicular quartz) (Collins 1988, 1997a; Figure 1). The granitic rocks in these places were produced by chemical replacement processes (metasomatism) of previously solidified igneous rocks at temperatures below those required for melting (350–550ºC).
The evidence that such granite is formed by metasomatism consists of detailed thin section studies, electron microprobe analyses, and cathodoluminescence images of undeformed diorite through a transition of deformation into granite where calcium, sodium, iron, magnesium, and aluminum were subtracted as potassium and silica were introduced (Collins 2002). The resulting metasomatic granite that is formed at temperatures below melting conditions looks like granite that has crystallized from magma because the newly formed granite inherits the mineral textures and structures (dikes into wall rocks and inclusions of foreign rocks) of the original igneous rock (for example, diorite), but now the rock’s mineral and chemical compositions have been changed into what occur in granite. The process is similar to the formation of petrified wood in which silica atoms are brought in and exchanged for carbon atoms, preserving the cellular structure of the wood, except that in the metasomatic granite, potassium is exchanged for sodium and calcium, converting plagioclase feldspar into potassium feldspar while preserving the original shapes of the plagioclase crystals. Some of these same myrmekite-bearing microfractured granitic rocks contained scattered but relatively abundant uranium (238U) in crystals of uraninite and zircon, so a nearby source for radioactive radon gas (222Rn) was readily available, as were polonium 218Po, 214Po, and 210Po, the three daughter isotopes of 222Rn. Fracturing of the rock that is intense enough produces open spaces that became filled with the dissolved elements that ultimately formed calcite veindikes containing biotite (and fluorite) with polonium halos (Wakefield 1987–8, 1988). Coarse-crystalline pegmatites were produced in other places in this same area when closely spaced microfractured rocks were converted to granite by replacement processes. Uranium continued to supply large amounts of radioactive radon and polonium once it became concentrated in, or was in route to, these lower-pressure microfractured places. This accumulation of radioactive elements in the lower pressure sites enabled polonium to nucleate in growing or recrystallizing crystals of biotite mica (and fluorite).
Polonium ions nucleate in biotite and fluorite because these ions are large and can fit only in large sized holes in a mineral lattice. Such holes occur in biotite and fluorite but not in the other kinds of minerals commonly found in granite. The polonium ions nucleating on the faces of growing biotite crystals and fluorite subsequently became enclosed inside these crystals. The enclosed polonium ions would then begin to decay and emit alpha particles. The alpha particles, shot out in random patterns, would cause damage to the crystal lattice producing spheres with different radii, destroying the lattice structure and producing a disordered pattern, known as a glass, which appears as a black circular spot under the petrographic microscope. Rings of these different radii of damage can be seen if these spheres are cut through in the plane of the equator. Such rings are referred to as halos — hence, 218Po, 214Po, and 210Po halos. From 9 to 10 billion atoms of polonium are needed at a nucleation point before individual halos can be seen (Gentry 1988). This means that vast numbers of polonium atoms were once present in the crystals of biotite before these atoms all eventually decayed to stable lead (206Pb).
Examples of the three types of polonium halos can be seen below the geologic map of Wakefield (1987–8). Figure 2 shows schematic diagrams of the rings (halos) of damage for the three polonium halo types and for a uranium halo. The uranium-halo schematic shows that the three polonium isotopes are the last three daughter isotopes in the eight-step decay of 238U, each step losing a mass of 4. On that basis, the 218Po halo with its three rings, the 214Po halo with its two rings, and the 210Po halo with its one ring are isolated (separate) from any immediate uranium source, but, of course, the polonium ions that nucleate to produce these halos are derived from some nearby uranium source.
|FIGURE 2. A. Schematic drawing of 238U halo with radii proportional to ranges of alpha-particles in air. B. Schematic drawing of 218Po halo. C. Schematic drawing of 214Po halo. D. Schematic drawing of 210Po halo. (From Collins 1988.)|
Numerous polonium halos occur per cubic centimeter in the biotite “books” in the calcite vein-dike of the Silver Crater Mine (figure 14 of Wakefield 1987–8). (Numerous could mean 20–30 thousand polonium halos per cubic centimeter in biotite as reported by Gentry  in a Norwegian mica.) Biotite at the Silver Crater Mine and fluorite in calcite vein-dikes in the Wilberforce area show no evidence of any fracturing that would provide avenues along which radon gas and ions of polonium could move to nucleation points. The growing crystals of biotite and fluorite would be inside large volumes of hot gaseous fluids occupying the open fracture and would not be expected to be fractured or deformed. The Wilberforce area can be seen on the edge of the geologic map in Wakefield (1987–8) west of the Fission Mine where the last four letters “orce” appears.
After crystallization in the calcite vein-dikes, ongoing replacements can continue to occur, involving multiple deformations in the adjacent granitic rocks that allow more fluids to come into the vein-dikes. Both biotite and apatite are reported to replace calcite in some of the vein-dikes in the Bancroft area (Wakefield 1987–8, 1988). These second growth biotite crystals also contain polonium halos, indicating that the hydrous fluids causing these additional replacements carried 222Rn and polonium isotopes.
Because the location where Gentry (1988) reported some of his best polonium halos in biotite (and fluorite) was not in granite but in a calcite vein-dike near the Silver Crater uranium mine in the Bancroft area of Ontario, Canada (Gentry 1971, 1974; Wakefield 1987–8, 1988), his claim for nearly instant crystallization of granite is immediately nullified. In his model, all biotite containing polonium halos crystallized in granite formed from magma. Calcite vein-dikes, however, do not form from granite magma at any stage of its crystallization. Such vein-dikes fill fractures (a meter or more wide) in previously solidified granitic rock and are, therefore, later than the crystallization of the granite (Wakefield 1987–8, 1988).
Gentry claimed that biotite (and fluorite) crystals containing polonium halos always lacked any microfractures through which radioactive radon or polonium ions could penetrate to produce the polonium halos. This is not true. The adjacent granitic rocks have microfractures where pegmatites were formed by recrystallization and replacement, such as the Buckhorn pegmatite in the Bancroft area. The crystals of biotite crystals in such places that contain polonium halos show evidence of microfracturing or evidence that they had microfracturing prior to recrystallization (Collins 1997b).
|FIGURE 3. Biotite with a band of lattice damage along a microfracture by radiation from 222Rn, 210Po, 214Po, and 218Po atoms; black circular dot is a 210Po halo; from Buckhorn pegmatite in plain light.|
For example, in Figure 3, a band of alpha-particle damage can be seen where radioactive inert 222Rn gas and 210Po and 218Po ions were once migrating in fluids along a fracture in the crystal of biotite. These three isotopes produce radii of damage that are almost the same distance from the center line of the fracture so they are not distinguishable from each other in the band of continuous overlapping damage which produces a smeared-out band of damage to the lattice of the biotite. Billions of radioactive isotopes once moved along this fracture, shooting out alpha particles as the fluids progressed through the fracture. Sufficient 210Po (9 billion atoms or more) nucleated at one place along the fracture to create the isolated black 210Po spherical halo of damage. Another example of a fracture containing a 210Po halo in biotite is shown in figure 4 of Collins (1997b). The assertion by Gentry that polonium halos are never found along fractures in biotite is not true.
|FIGURE 4. Circular and oval dark U-halos of alpha-particle lattice damage in biotite surrounding tiny U-bearing zircon crystals in granite in cross-polarized light.The thin section showing these halos are too thick to show the eight rings of damage.|
Gentry believes that granite and polonium-halo-bearing biotite had to form nearly instantly on Day Three of the Genesis Week. He argued, therefore, that the rate of crystallization of granite must be exceedingly fast. Snelling (2008b) suggested that the granite formed in 6–10 days. In contrast, silicate crystals (quartz, mica, feldspars, and so on) in deep-seated magma normally grow exceedingly slowly (over thousands and millions of years) because (1) the heat in molten rock at great depth escapes only very slowly to the earth’s surface so that the rate of cooling is very slow, (2) the high viscosity of the silica-rich melt (like a hot, thick, molten, silica glass) prevents metallic ions from diffusing quickly to nucleation and growingcrystal- sites, and (3) water (steam) that would facilitate rapid diffusion of such ions is generally absent.
However, the rate at which silicate crystals grow in granite pegmatites (where large crystals several centimeters wide may form) can be rapid because of the local great abundance of water (steam). The abundant water occurs because water tends to concentrate in localized volumes in late stages of crystallization of magma because most minerals crystallizing in granite lack any water in their lattices, and it is where abundant water is present that pegmatites form. Crystals in pegmatites can grow to large sizes in a matter of a few days or weeks (London 2008; Nabelek and others 2009; Sirbescu and others 2008; Webber and others 1999).
The rate of growth of calcite and biotite in fluids where calcite vein-dikes form must be even faster than the rate of growth for silicate minerals crystallizing in pegmatites in a granite body. The fluids that produce the calcite vein-dikes would have a high water content and notably low silica so they would have low viscosity. The growth of large crystals of biotite (and fluorite) crystals could, perhaps, be in a matter of hours or less, and, therefore, the growth of superposed lattice layers would also surround nucleating polonium ions on the faces of the growing crystals. Thus, thousands of polonium halos per cubic centimeter in crystals of biotite and fluorite are possible lacking any evidence for microfractures.
Gentry rejected the model for granite’s being formed by chemical replacement processes because there was no publication in refereed geology journals of a large-scale chemical-replacement model for the origin of some granitic masses. However, several recent studies have indicated the presence of large scale metasomatic (replacement) processes. Andrew Putnis and colleagues, using microprobe studies on an atomic scale, have confirmed that a chemical replacement model for the origin of some granite masses is correct (Putnis and others 2007; Engvik and others 2008; Plumper and Putnis 2009). The evidence for this replacement is the presence of numerous tiny pores in plagioclase feldspar crystals in primary igneous rocks that were deformed and microfractured. Fluids moved through these pores and brought in potassium and/or sodium while depositing tiny rosettes of red hematite crystals along the walls of the pores. The introduction of the potassium and/or sodium converted large masses of igneous rocks into granitic rocks (with surface areas several kilometers in diameter) in Finland, Sweden, Brazil, and California. Where potassium was introduced, myrmekite (similar to that in Figure 1) locally borders the potassium feldspar in these rocks (Collins and Collins 2002). The presence of myrmekite alone can indicate that the rock system was open to ready movement of fluids that could have contained dissolved radioactive radon and polonium ions (if available). Myrmekite is formed locally where chemically altered lattices of relatively calcic plagioclase are incompletely replaced by potassium feldspar, leaving residual calcium, sodium, aluminum, and silica atoms in the lattice which are not in proper balance to recrystallize only as more sodic plagioclase; so some silica is left over to recrystallize as quartz vermicules (Collins 1997a). During metasomatism the reactions do not occur in balanced mass-for-mass exchanges, as one is taught in chemistry classes, but by volume-for-volume exchanges of elements (ions) in minerals that have different densities.
Other published examples of large-scale chemical replacements by potassium feldspar come from economic geologists. For example, Doucette (2000) reports that such replacements occur in volcanic porphyry where gold and copper enrichments are found, converting plagioclase phenocrysts into potassium feldspar (see figure 27 in Doucette 2000). Large-scale potassiumfeldspar replacements, extending over hundreds of square kilometers, are reported by Liu and others (2003) in the uppermost Precambrian rocks underlying Paleozoic sedimentary rocks in the North American mid-continent.
Uranium halos are commonly found throughout a granite mass; isolated polonium halos are rare or absent (Figure 2). Uranium in magma is incorporated into crystals of zircon or uraninite as the magma cools and solidifies. The element preferentially enters into zircon’s crystal structure because uranium’s ionic charge (4+) is the same as that of the zirconium ion. Cooling magma is normally too viscous for large amounts of uranium or zirconium ions to diffuse. Most uranium and zirconium ions, therefore, move only very short distances, precipitating in tiny crystals of uraninite or zircon, or the uranium is precipitated only in crystals of zircon, which are scattered throughout the granite mass. These tiny zircon or uraninite crystals are then enclosed in, or fill spaces in between, other silicate minerals that are crystallizing in the granite mass, such as quartz, feldspars, and biotite. Once the crystals in the granitic mass have formed, any polonium that would be produced must be derived from the decaying uranium in the zircon crystals that had already nucleated and been incorporated in the crystallized biotite and could not then nucleate in later-formed biotite to create visible isolated polonium halos. Only 238U halos including eight spheres of damage surrounding the zircon (or uraninite) crystals would be produced following the solidification of granite magma. These eight spheres have a common center where the uranium is concentrated, and each sphere has a different radius that corresponds to the energies of emissions of alpha particles from each of the eight daughter isotopes in the 238U decay series until stable lead 206Pb is formed (Collins 1997b). The last three isotopes in the 238U decay series are 218Po, 214Po, and 210Po, so their halos are part of the eight produced in the adjacent biotite bordering the uranium source and do not occur as separate isolated halos (Figure 2). The damage in biotite surrounding 238U-bearing zircon crystals in granite can be seen as circular or oval black halos outlining the shapes of the zircon (or uraninite) crystals under the petrographic microscope (Figure 4). The thin section is too thick, however, to see the eight separate halos.
It is also important to point out that the ratio of the amount of lead 206Pb to the amount of the remaining uranium 238U in zircon crystals is used by geochronologists to determine the age of the crystallization of the granite. Because the age determined by this method is consistent from place to place in the same granite (within experimental error), this consistency indicates that the decay process for 238U obeys natural laws that are not arbitrary, which in turn validates the use of this method for determining the age of a granite body (Dalrymple 1991). This applicability in two (or more) places of the results of a single principle based on the observation of natural processes in a way that is consistent with findings from other models and methods of analysis, such as rubidium-strontium (Rb-Sr) and potassium-argon (K-Ar) age determinations, reinforces the validity of the uranium-lead (UPb) age determinations.
The formation of isolated polonium halos in magmatic pegmatites, on the other hand, is possible because of the very large atomic size of the uranium atom (ion), which causes some uranium atoms to be concentrated in both zircon crystals and in residual hydrous fluids during last stages of crystallization of granite magma. Atoms (ions) that are either too small or too large to fit in stable arrangements in holes in the lattices of such silicate minerals as biotite, plagioclase feldspar, and potassium feldspar that are common in magmatic granite are left over in the residual fluids of the last stages of solidification of granite magma (Klein and Hurlbut 1985). For example, smallsized atoms (ions) of lithium, beryllium, and boron (elements numbers 3, 4, and 5) are commonly crystallized in late-forming pegmatites in gem minerals. Atoms that are too large include gold (element number 79) and uranium (element number 92). Uranium is commonly found in scattered zircon crystals in granite (as noted above), but some uranium may also be concentrated in late stages of granite crystallization in pegmatites in the mineral uraninite because of its very large atomic size. Biotite and fluorite crystallizing near this uraninite could plausibly contain Pohalos because the concentrated uranium atoms in this uraninite and in fluids bringing this uranium to the pegmatites would be an abundant source of radon 222Rn and polonium isotopes.
Gentry (1988) actually includes an illustration of a large biotite crystal containing polonium halos in a pegmatite from Murray Bay, Canada. This pegmatite contains crystals of beryl, zircon, and uraninite (Spense 1940). The association of the gem mineral beryl with biotite probably indicates an origin by crystallization of this pegmatite from magma. The biotite would not be microfractured in such an environment, and the presence of abundant steam would permit rapid growth of large crystals. This mineral association in no way indicates that the pegmatite had to crystallize nearly instantaneously. Furthermore, biotite crystals in pegmatites that lack uraninite also lack polonium halos. The presence or absence of polonium halos in biotite in magmatic pegmatite is directly related to the presence or absence of nearby uranium in uraninite or zircon and not because of instant cooling.
The absence of microfractures in some polonium halo-bearing biotite and fluorite is plausibly explained where these minerals grew in former large, open fractures that were ultimately filled mostly by calcite. In microfractured granitic rocks that were modified by metasomatic processes, polonium halos can form along microfractures in biotite. The rapid rates at which crystals can grow in calcite vein-dikes or pegmatites in the presence of steam and the rapid rates at which radioactive isotopes can diffuse from areas of relatively high pressures into possible large open fractures are important factors in the formation of polonium halos. The coexistence of uranium-bearing minerals in calcite vein-dikes or pegmatites which release abundant amounts of radioactive radon 222Rn and the easy transport or diffusion of uranium and polonium ions and neutral radon gas in surrounding microfractured rock are also necessary. Also important is the relatively long half-life of 222Rn (3.82 days). All these factors provide the means by which polonium halos are formed in biotite and fluorite by natural processes.
The absence of microfractures in biotite (or fluorite) where these minerals grew in pegmatites that were crystallized during the last stages of the solidification of granite magma is plausibly explained because crystals forming in magma are generally not microfractured. Moreover, it is plausible that polonium halos can form in pegmatites of magmatic origin because of the transport or diffusion of uranium and polonium ions and neutral radon gas in steam that is concentrating in local places during the last stages of crystallization of granite magma.
Granite bodies of both primary magmatic and secondary chemical replacement origins are not created during a single young age in the Genesis Week but are among a continuum of ages that range from early in the Precambrian to the late Cenozoic. The one essential requirement for polonium halos to form in biotite and fluorite in calcite vein-dikes or granite (either produced by chemical replacement processes or by magmatic processes) is the nearby presence of uraniumbearing minerals that supply the large quantities of radon 222Rn and polonium.
If polonium halos truly had a nearly instantaneous origin as suggested by Gentry (1988), then even more examples of other polonium halo types would be expected to occur, such as (1) halos of 215Po and 211Po that are derived from radon gas 219Rn in the radioactive uranium (235U) decay series or (2) halos of 216Po and 212Po that are derived from radon gas 220Rn in the radioactive thorium (232Th) decay series. But they are not found (Collins 1997b). The reason is that the radon gas atoms (219Rn and 220Rn) in these two decay series which are the precursors for the other radioactive polonium isotopes have half-lives in seconds, and their daughter polonium isotopes have half-lives in seconds and microseconds instead of 3.05 minutes for 218Po and 140 days for 210Po in the 238U decay series (Collins 1997b). However, Gentry found only one kind of Po-halo sequences among three possible kinds in biotite and fluorite of supposed instantaneous origin.
We wish to thank Mona Sirbescu for providing information regarding rates of crystallization of pegmatites. We express our appreciation to Richard Wakefield for correcting information about the geology and descriptions of the vein-dikes in the Bancroft area of Canada, Steve Lipshie for editorial suggestions and checking the clarity of the article, Forrest Hopson for suggesting many editorial changes and for annotating illustrations, and John Doucette for recommended style changes in writing the article.
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210Po — an isotope of polonium, element number 84,having 84 protons in its nucleus and 126 neutrons for a total mass of 210
alpha particle — a helium atom with a mass of 4
biotite — black mica, a sheet-structure silicate mineral
calcite — calcium carbonate
diorite — a dark-colored, coarsely crystalline igneous rock commonly containing hornblende, biotite, and plagioclase
fluorite — calcium fluoride half-life—the time for half the quantity of a radioactive element (isotope) to decay to a daughter isotope
hornblende — a black silicate mineral rich in iron and magnesium
ion — an atom with a negative or positive charge
isotopes — variants of the same element with the same number of protons in the nucleus but differing numbers of neutrons so that the total mass of the element is different
magma — melted igneous rock
myrmekite — an intergrowth of two minerals (plagioclase and quartz). It is commonly wartlike (
pegmatite — a coarse silicate igneous rock containing crystals generally larger than 2 centimeters long. Some pegmatite crystals may be more than a meter long
phenocryst — a crystal formed from magma and much larger than surrounding ground mass crystals
plagioclase — a feldspar that ranges from sodium-rich varieties to calciumrich varieties. In granite this feldspar contains much more sodium than calcium
radon — a neutral gaseous element with no ionic charge
vein-dike — a former open fracture that cuts across the rock structure and is filled with various minerals, such as calcite, quartz, and biotite
uraninite — uranium oxide
vermicules — quartz shaped like curved worm tubes
vermicular — having the shape of worm tubes
volcanic porphyry — a volcanic rock containing phenocrysts
zircon — zirconium silicate;large crystals can be gemstones, but tiny crystals commonly form in granite
The idea of a graphic version of the Origin of Species is a good one, since many casual readers will never get through the original. This is perhaps unfortunate, but so much misinformation is available on evolution in the popular literature that any attempt to clarify Darwin’s views on evolution by natural selection has to be welcomed. A graphic format might be easier to read and understood by those who have no time to read more deeply or are casually interested, but do not want to commit more time on it than a graphic format would require. Some of this audience would certainly include students, especially in high school. Years ago I found the book Darwin for Beginners by Jonathan Miller and illustrated by Borin Van Loon (New York: Pantheon, 1990) to be a rather charming graphic account of Darwin’s ideas, and it is still available and of use in this regard. In this same genre, Rodale Press has recently published Michael Keller’s Charles Darwin’s On The Origin of Species: A Graphic Adaptation.
I did not particularly like the illustrations, but tastes differ. When Nicolle Rager Fuller (the illustrator) concentrates on animals, she does very well, but her people sometimes are a bit strange. While I don’t think the illustrations are up to more rigorous scientific standards, they are more than adequate for a book of this nature.
However, the main point is that the theory of natural selection is well covered and I think pretty well explained in Keller’s book. Compared to Miller, Keller concentrates more on the basic ideas in each chapter of the Origin and less on the historical and philosophical background. His treatment of modern ideas in regard to evolution is also more up–to–date. Starting in part 2 on page 41, after 34 pages of background, Keller goes through each chapter of the Origin, briefly summarizing the evidence and arguments used by Darwin. These summaries are generally accurate and present the reader with at least the main ideas involved, although some topics get lesser treatments than others. The discussions of variation under domestication, the difficulties of the theory, geographical distribution, and mutual affinities of organic beings, are especially well done. The last chapter brings the reader up to the present with short panels on Mendel and genetics, the Synthetic Theory, genes and the discovery of DNA as the blueprint for life, jumping genes, and punctuated equilibrium, among others.
I have a few gripes, which primarily have to do with content. For some reason, Keller apparently used later editions of the Origin in which Spencer’s phrase “survival of the fittest” was added. Darwin did not invent this phrase and it was not in the first edition. The phrase, while accurate if “fit” is understood to apply to any adaptation that works to allow an individual to reproduce, does not necessarily mean that the strong overcome the weak; Spencer’s phrase has unfortunately been used to imply that there are “inferior” peoples because they do not fit preconceived notions of superiority. It would have been wise for Keller to explain this if he was going to use a later edition of the Origin.
I can also quibble with the fact that while Keller abruptly introduces Emma Darwin as Charles’s wife on page 26, he never really explains her background or the circumstances of their marriage (they were first cousins, which concerned him later because of problems that he perceived with inbreeding). Also unaddressed is her religious faith (she was a devout Unitarian) and how it affected their relationship. The death of Annie, their beloved daughter, discussed on page 31, apparently caused Emma to doubt her beliefs; when Darwin died, Emma refuted the rumor that he had recanted his agnosticism on his deathbed. These are important points to discuss if Emma and Annie are introduced, and I felt they were given short shrift.
There were several other places in the book where new subjects seemed to be introduced without much in the way of a connection to what went before, and some important points about modern theory were glossed over in my view, but in a book of this nature some information has to be omitted.
Finally, I found an unfortunate error on page 14: Robert Chambers’s and John Henslow’s occupations are reversed. Chambers was a journalist and author (Vestiges of the Natural History of Creation) and Henslow was a botanist and geologist, as well as mentor to the young Darwin. The reader should not expect an in–depth treatment in what is essentially a comic book, but these were errors that could have been easily avoided.
That said, Keller has produced a mostly accurate and reasonably complete book that introduces the intelligent layperson to the principles of and evidence for evolution by natural selection. It certainly will serve as a good introduction for high school students or for an introductory course for non–biology majors in college. Those who want more depth to the background information on Darwin’s life would do well to read Janet Browne’s two volumes on the subject, and those who would like more detail about Darwin’s arguments should read a reprint of the first edition of the Origin. But the more casual reader will find a reasonably good synopsis of the theory and its more modern developments within the pages of this book. It is to these readers that I recommend this slim volume, with the minor reservations mentioned above.
As a theologian at the University of St Thomas (St Paul, Minnesota), Tatha Wiley engages Darwinian thought in order to gain insight into the doctrines of Christianity. She emphasizes that the theological concept of creation contrasts with the anti–evolutionists’ political definition of “intelligent design” (ID) creationism — a neo–Paleyan construct based in the teleological argument for God. She agrees that supernatural agency must be “bracketed” when doing science. Unless one misreads Genesis as offering an alternative scientific explanation, there is no conflict between Christianity and Darwinian science.
Fundamentalists see the Genesis stories as history and science. Wiley explains why the antimodern and anti–intellectual fundamentalist movement in the US, with its idea of a “plain sense” reading of Scripture, is just flat wrong. Ever since the inception of The Fundamentals in 1909, fundamentalists have ignored a more informed biblical scholarship. Reading the creation stories as symbolic narratives, instead of history, transforms Adam and Eve into a metaphor for human experience; it is a non sequitur to claim that doing so makes Christ a metaphor as well. What impels this non sequitur is what Wiley calls the “fundamentalist anxiety.” Understanding this anxiety, Wiley suggests, should help us gently communicate the science of evolution to fundamentalist students.
The theological concept of creation and evolution address two different realities on both ontological and epistemological levels. They are complementary answers to different questions: whys versus hows. Wiley makes clear that theology, done properly, addresses metaphysical questions of human existence. Questions of an ultimate source of the universe (God) belong to metaphysics and outside the bounds of science. Taking what was meant to be a hymn of praise to encourage exiles to remain loyal to Yahweh (Genesis 1–3) and turning it into a science and history lesson is an incompetent exposition of scripture. Science, by its very nature, must limit itself to physical questions. Just as we wish to keep ID out of our classrooms, we must also keep out metaphysical claims that science proves a dysteleological or atheistic cosmos.
Wiley highlights the flaws of the teleological argument, which claims the order of the cosmos indicates a designer. Rather than ignore the dysfunctions and cruelties in nature, which Paley’s natural theology failed to explain, Darwin solved the conundrum by proposing that whatever allows the better proliferation by an individual in a given environment is what truly counts, not how perfectly that individual serves a purpose in nature. More importantly, natural selection is an empirically based explanation amenable to testing and verification.
Wiley also explains how Roman Catholics have used evolution to inform theology. Both advances in evolutionary science and the work of biblical scholars continued to question the historicity of Adam and Eve and thus the doctrine of original sin. Developed primarily by St Augustine and given dogmatic status by the Council of Trent in 1563, the doctrine reflected a medieval worldview. The Church began considering evolution and modern critical methods of biblical scholarship seriously in 1943. By 1950, Pope Pius XII cautiously accepted evolution but could see no apparent way to reconcile it with the doctrine of original sin.
By 1996, Pope John Paul II recognized evolution as “more than a hypothesis”, noting that even if the body is brought into being by evolutionary processes, the soul is immediately created by God. By shifting to a mystical “ensoulment” of an “Adam” (humankind), he moved the discussion to one of metaphysics outside the purview of science. In 2004, a Vatican statement accepted evolutionary theory as compatible with divine purpose warning only that science should never engage in metaphysical claims that the cosmos has no purpose, humans have no ordained role to play, or God has no function in an evolving universe.
Fundamentalists never signed on. Some of them became a political movement focusing, via the Discovery Institute, on “irreducible complexity”, requiring an “intelligent designer”. Their “God–of–the–gaps” arguments make God dispensable when intelligible natural explanations eliminate the gaps in current knowledge. Consequently, ID does no favors for theology. Good theology prefers God to remain mysterious and ineffable rather than continuously shrinking as gaps are filled.
The insistence that science restrict itself to the study of natural causes is not a rejection of God’s existence. It is a methodological approach to limit science to what is testable. The ID camp fails to understand that science is limited to discovering secondary causes of contingent events (such as laws of nature). Science must bracket a primary cause of those laws. Seeing God as the ultimate source of secondary causes allows theologians to understand him or her as the prime mover, the ground of being itself ... conceptions that belong to metaphysics. ID casts God as a tinkerer who could not get it right the first time — poor science but even worse theology.
The final chapter focuses on the crux of the conflict: without a historical Adam and Eve in Eden, is Christ’s atonement moot? I have to wonder why Wiley was not more forthright in answering with a resounding “no” since her previous publications do this quite well. If I can fault this work at all, it would be here. After all, the resolution of anti–evolution as pointed out by Wiley, echoing Eugenie C Scott’s position, is to educate both scientists and theologians: to allow both to become better informed about biblical scholarship and what scriptures are actually teaching regarding the doctrine of creation. Personal interpretation of Scripture without solid theological insight — so–called plain “sense” readings — must be rejected ... as the Ethiopian admitted when Philip asked him:
Do you know what you are reading?
How can I, unless someone explains it to me? (Acts 8:30–31).
When the National Center for Science Education asked me to review Darwin’s Ark, I demurred, saying I was not a scientist and while a sometimes poet, certainly not Philip Appleman’s peer. As for drawings, I only know what I like. The NCSE replied I was exactly what they wanted. Feeling somewhat ridiculous, I agreed. But as Appleman points out so aptly in his poems, Homo sapiens many times is ridiculous. Appleman is the Distinguished Professor of English Emeritus at Indiana University and author of eight volumes of poetry, three novels, and six non–fiction books including the Norton Critical Edition of Darwin. Rudy Pozzatti is Distinguished Professor of Fine Arts Emeritus at Indiana University, whose art resides in museums and public and private collections worldwide.
I first became aware of Philip Appleman’s ability to take seldomaddressed subjects, put them into poetic form, and subject them to public scrutiny in 1984 when his poem “The Skeletons of Dreams” hit me with the power of a hydrogen bomb. I sang its praises in freethought newsletters and read it to graduate students attending a talk at Guangxi Province Teachers’ University in Guilin, China. I was awestruck the many times I have read the poem since.
The poem first appeared in The New York Times and was subsequently included in his 1984 collection of poems entitled Darwin’s Ark. But “Skeletons” is only one star in a glittering galaxy of poems and illustrations (and excerpts from writings by Darwin and others) that add to this volume. Appleman illuminates his theme with empathy, understanding, wit, and humor that is often subtle or satirical. Pozzati’s illustrations, while often whimsical, are also realistic and memorable.
The words and drawings in Darwin’s Ark brilliantly exhibit Darwin’s theory of evolution, starting with “Skeletons of Dreams”. In it Appleman includes these cautionary words,
Back home in his English garden
Darwin paused in his pacing,
writing it down in italics
in the book at the back of his mind:
When a species has vanished
from the face of the earth,
the same form never reappears ...
The poem goes on to point out humanity’s acquisition of an opposable thumb and an expanded cerebral cortex, and the millennia linking us to our ancestral past, while pointing out that our species is still as mortal as mammoths.
All of the poems delineate, describe, or elaborate on Darwin’s theory. The connections between us and them, humanity and the “lesser” animals, slide effortlessly into place, and the very earth we stand on oozes into our consciousness as we read these poems. Appleman blends the past with the present in an elegant fashion.
A sensitive, analytical writer, Appleman takes us into the scenes he paints with his words. We are the lions in the veldt. We feel the sense of urgency in the hunt, whether it is in grasslands in Africa or pews in churches, preachers “baying at sin.” He uses metaphor in amusing ways as well, and we read about the evolution of automobiles, the passing of Cords and Duesenbergs, and “animals tame and animals feral.” Rhymed or unrhymed, all the poems sing with the rhythm and the judicious choice of words.
The book is separated into four sections, Giants in the Earth, The Rust of Civilizations, Animals Tame and Animals Feral, and In the Caves of Childhood. The poems in each section tie the present to all that went before and at times point to the future. In an additional breakdown of the section highlighting animals, we find Phobias (fears) and Euphorias (joys), and these playful seeming titles end up, by the end of the poems, giving us very big challenges, making us look at ourselves and what we have wrought.
Open the book anywhere and you are apt to find an image that expands in your mind, becomes more because of the verbs used — “the concrete is veined with tar bubbling in the sun” or “the land is failing the horizons.” Again a wellchosen adjective lifts a narrative above the obvious such as “to pray above our crippled brother seven raptured hours.”
Darwin’s observations and conclusions have been encapsulated and given back to us in poetic form expanding on the various concepts Darwin noted. We encounter the “survival of the fittest.” We know what it means in a visceral, on–the–scene way in the cold regions of Tierra del Fuego during the “spirit” years. We know what it is to be hungry, when food exists only in another like ourselves. We know what it is to be the hunted, to be the prey. Likewise Appleman makes clear that Noah’s Ark was “not floating on fact but was floating on faith”. Darwin’s Ark floats on word images and the underlying science as well as the social behavior that speaks and lives for all times.
The poem “Reading Our Times” contains the following end lines:
we push though the bars
to Wall Street, promised land,
land of silk and honey,
bearing our Times
into the screaming of monkeys,
into the streaming baobab,
ivory, apes, and peacocks,
hacking at dripping lianas
with our machetes, tracking the gamy spoor
The prescient lines could have been written today.
For anyone interested in a wideranging and detailed treatment of the “intelligent design” (ID) controversy, a thorough reading of the transcripts from Kitzmiller v Dover Area School District would be recommended, except that it is extremely long, tedious, and often bogged down in the minutiae of legal proceedings. Nonetheless, a selective glimpse at the testimony is insightful. At issue in Kitzmiller was a statement directing students to “keep an open mind” “because Darwin’s Theory is a theory” and informing those who were interested in an alternative view that the ID “reference book” Of Pandas and People was available.
In his introduction to The Panda’s Black Box, Nathaniel Comfort attempts to unpack the current teach–the–controversy strategy. He concludes that the controversy that exists between ID proponents and advocates of mainstream evolutionary theory “is not about the findings of science. Rather, it is about the place of science in society” (p 7). Comfort champions teaching the controversy, as long as it is taught in a humanities environment that is equipped to handle the rhetoric, dogma, values, and the political baggage that it entails.
Scott Gilbert, the only biologist among the contributors, provides an interesting look at what it would take for biologists to “teach the controversy”. Using his experience teaching developmental biology, he lampoons ID as “what science might be if it lost its respect for evidence and controls” (p 41) and adds that “the debate between evolutionary biology and ‘intelligent design’ is like a debate over whether the aerodynamics of the Boeing 747 are superior to those of flying carpets” (p 43). These oneliners aside, Gilbert’s central theme — that it is important to separate the scientific content of a theory from its science–like packaging — provides a resonant theme.
Michael Ruse and Edward Larson provide histories of the design argument and teaching evolution in public schools, respectively. Ruse’s piece distills portions of his much more substantial Darwin and Design: Does Evolution Have a Purpose? (Cambridge [MA]: Harvard University Press, 2003) to provide a history of the design argument that stretches from the ancient Greeks to the contemporary ID movement. He rejects the claim that ID represents a breakthrough in scientific thinking.
Likewise, Larson, author of Trial and Error: The American Controversy over Creation and Evolution (third edition, New York: Oxford University Press, 2003) and Summer for the Gods: The Scopes Trial and America’s Continuing Debate over Science and Religion (New York: Basic Books, 1997) condenses substantial scholarship to trace the debates over evolution in the public schools from the 1920s into the 21st century. Beyond the abridged history, Larson touches on the role played by scientists’ attitudes toward religion in shaping the ongoing controversy and on the impotence of our court system when it comes to solving the public controversy.
Jane Maienschein uses the current controversy over human embryonic stem cells to illustrate how the public presentation of purported science–religion battles generally fails to capture the range of issues involved. Her discussion attempts to separate facts, on which there may be little disagreement (for example, that a fertilized egg contains a full complement of DNA), from values, on which there is generally little agreement (for example, “What rights or respect should be afforded to an embryo?”). She also separates metaphysical debates (that is, those about what exists) from epistemological debates (that is, those about how we know things). By citing the centrality of evolutionary theory to any hope of finding a competent response to threats such as the H5N1 strain of avian flu and the loss of biodiversity, she provides the most compelling case for choosing evolution over ID for our classrooms and policy–making arenas.
Robert Maxwell Young’s discussion of scientific reductionism, materialism and the fact–value distinction as sources of the science–religion divide illustrates at the often–ignored complexity of the science of human nature. Rather than attacking either ID proponents or evolutionists, he provides a useful examination of historical transitions that accompanied the shift from natural theology to materialist science. The centerpiece of his discussion casts Darwin’s theory as “arguably the most important idea in the history of the natural or human sciences” (p 13).
The Panda’s Black Box is an accessible reader that quickly and deftly surveys the current evolution– ID debates from a range of philosophical and historical angles. It provides a useful synopsis of considerable scholarship on the issues involved. Despite the considerable abridgment of several lines of argument owing to its brevity, it manages to convey a sense of the debates that is accessible and sufficiently footnoted to allow those who are so inclined to dig deeper into the quagmire of “the controversy” surrounding the place of science in our society.