George Will Responds; Sinks Deeper

George Will published a defensive editorial today regarding his much criticized recent column on global warming. His defense, as contained in the column and as articulated by his editor, basically boils down to this: "I can interpret the data how I want to. That, and reporters at the New York Times are jerks."

In addition, in an attempt to shore up his credibility Will further injures it by writing:

On Feb. 18 the U.S. National Snow and Ice Data Center reported that from early January until the middle of this month, a defective performance by satellite monitors that measure sea ice caused an underestimation of the extent of Arctic sea ice by 193,000 square miles, which is approximately the size of California. The Times ("All the news that's fit to print"), which as of this writing had not printed that story, should unleash Revkin and his unnamed experts.

Problem: The sensor problem did not affect the ACRC's data--the data on which Will staked his claim. Further, taken on its own it still doesn't help him because Arctic sea ice is still down. Also, Revkin has taken up Will's challenge.

My last post, George Will, Global Warming, and Accuracy, gave an overview of the controversy that remains relevant in light of Will's latest column.

For Carl Zimmer's summary and analysis of the latest, see Unchecked Ice: A Saga in Five Chapters, and Ice, Ice Baby: When Fact-Checking Is Not Fact-Checking.

Andrew Revkin of the New York Times responds in Experts: Big Flaw in Will’s Ice Assertions.

Slate also has a helpful article that explains the significance of Arctic ice, and why it is considered separately from that of the Antarctic: Is the Cryosphere Crying Wolf?

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George Will, Global Warming, and Accuracy

Last week conservative columnist George Will published an op-ed in the Washington Post, Dark Green Doomsayers, wherein he reiterated his skepticism of global warming and portrayed it as hype, and it's been bouncing around the blogesphere ever since. I'll summarize what I've found and provide some links. The column makes several claims; the ones that have gotten the most attention are:

Claim: Back in the 1970s everyone was worried about global cooling, which turned out to be wrong.

Response: See my last post, The Global Cooling Myth. The article cited there actually refers to previous columns by Will as perpetuating the myth.

Claim: "...according to the U.N. World Meteorological Organization, there has been no recorded global warming for more than a decade, or one-third of the span since the global cooling scare."

Response: Nobody seems to know where this claim came from. Here is what I think is going on (as explained by New Scientist). Depending on whose data you believe, 1998 had either the warmest or second warmest global mean temperature since observations began. Let's compare the data from NOAA and U.K. Met Office Hadley Centre.





In the U.K.'s data, 1998 sticks out as the warmest year. Will and others who claim that warming has stopped are privileging the data for a single year above the overall trend. The U.K. data also show a slight cooling in the last few years. I'll leave it to the reader to decide what that means for the overall picture.

Claim: "As global levels of sea ice declined last year, many experts said this was evidence of man-made global warming. Since September, however, the increase in sea ice has been the fastest change, either up or down, since 1979, when satellite record-keeping began. According to the University of Illinois' Arctic Climate Research Center, global sea ice levels now equal those of 1979."

Response: Most of the focus has been on this one. Let's take it in basic chronological order.

Jan 1, 2009: DailyTech website published a story, Sea Ice Ends Year at Same Level as 1979, which reported that a quick recovery in late 2008 resulted in global sea ice levels equivalent to those at the end of 1979. At first glance, this would seem to negate worries about reduced ice.

Jan (?): In response to the story, the Arctic Climate Research Center (ACRC)--which was a source for the DailyTech story--published a clarification (pdf) noting that the article compared global sea ice area. However, Northern Hemisphere ice area has decreased, an observation in line with climate models, and Southern Hemisphere ice area has increased, which is in line with some climate models. Further, although the area may be the same, the new ice is thinner and so ice volume is down.

Feb 15: George Will's column was published, which apparently relied on the DailyTech article for its claim that current global sea ice is the same as 1979.

Feb 15+: In response to Will's column, ACRC put the following statement on their website:

In an opinion piece by George Will published on February 15, 2009 in the Washington Post, George Will states “According to the University of Illinois’ Arctic Climate Research Center, global sea ice levels now equal those of 1979.”

We do not know where George Will is getting his information, but our data shows that on February 15, 1979, global sea ice area was 16.79 million sq. km and on February 15, 2009, global sea ice area was 15.45 million sq. km. Therefore, global sea ice levels are 1.34 million sq. km less in February 2009 than in February 1979. This decrease in sea ice area is roughly equal to the area of Texas, California, and Oklahoma combined.

It is disturbing that the Washington Post would publish such information without first checking the facts.

The Post stands by the column and has refused to print a correction. In support of their position, they cited the first statement from the ACRC, which stated "Observed global sea ice area, defined here as a sum of N. Hemisphere and S. Hemisphere sea ice areas, is near or slightly lower than those observed in late 1979." However, critics point out that they ignored the broader context of the statement, which pointed out the shift observed in the individual hemispheres and lower ice volume.

Defenders of Will point out that at the end/beginning of 2008-2009, he was correct: global sea ice area was equivalent to the end of 1979. So the ACRC's refutation of Will based on February data is irrelevant to his point. I've altered a figure published by the ACRC to show this.



However, the broader context gives a slightly different picture (click to enlarge):


There seems to be a trend in recent years of reduction in global sea ice area. This can be seen both by the trend in the red line, as well as by comparing the upper blue line with the superimposed gray line.

As Carl Zimmer points out, comparing individual days thirty years apart does not give an accurate sense of the overall picture, which is illustrated by looking at the individual hemispheres.





Rather than criticize Will, Carl Zimmer is using this as a lesson on poor fact-checking by a major newspaper. (Part 1, 2, 3, and 4.)

Chris Mooney is using it as a lesson on the generally poor shape of newspapers (The George Will Scandal).

I should also point out that a New York Times story, In Climate Debate, Exaggeration Is a Pitfall, mentions Will's column, as well as the fact that Al Gore has removed a slide that he recently added to his presentation after the source for the slide complained that it was being misused.

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Update: (2/27/2009) George Will has responded in a new editorial. See George Will Responds; Sinks Deeper.

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The Global Cooling Myth

One of the charges that you may hear, which is intended to cast doubt on the reliability of climatologists and global warming, is that in the 1970s scientists were warning about global cooling and an impending ice age. This turns out to be mostly a myth.

Last September the American Meteorological Society (AMS) published an article in their bulletin called, "The Myth of the 1970s Global Cooling Scientific Consensus" (pdf), that explains the basis for this myth. The short version is that there had been some cooling since 1940 (see below). Climate science (which looks at long-term trends, not short-term weather) was a relatively immature science and some scientists were grappling with how aerosols could be responsible for the cooling. At the same time, other scientists were beginning to understand the pattern of long-term ice age fluctuations and predicted that on a geological time scale (i.e. thousands to tens of thousands of years), and ignoring human activities, the Earth should be heading for another ice age.

These factors combined with unusually severe winters in 1972 and 1973 and other fears of food shortages and so forth, and resulted in some hype in the mainstream media and increased public consciousness. In actuality, the effect of anthropogenic CO2 emissions was also being considered by scientists and there were already predictions of a warming trend. In fact a 1965 report by the President's Science Advisory Committee noted recent data on CO2 emissions and expressed concern about the potential for its warming effect on the climate.

The article points out that references to global cooling doom from the 1970s are usually drawn from popular publications such as Newsweek rather than the scientific literature of the time. In fact the authors did a literature search and categorized scientific publications according to whether they supported cooling, warming, or remained neutral. The following figure summarizes their results (click to enlarge):

Fig. 1. The number of papers classified as predicting, implying, or providing supporting evidence for future global cooling, warming, and neutral categories as defined in the text and listed in Table 1. During the period from 1965 through 1979, our literature survey found 7 cooling, 20 neutral, and 44 warming papers.

These data suggest that the notion that climate scientists (as a group) were warning of impending cooling only to reverse course and push warming, is false.

To finish, here is the global mean temperature from 1880 to 2007. The 1940s cooling is evident, as well as the overall warming trend.

Source: NOAA, Climate of 2007 Annual Report

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Revisiting Kinds

Recently the issue of created 'kinds' came up on another blog, and in the comments that followed it became clear that I needed to explain myself in greater length than would work well for a comment. So I promised to do a post here.

As background, one of the longstanding scripture-based charges leveled at evolution has to do with the description of 'kinds' in the creation account (or accounts, for LDS). The argument is usually something like the following: According to the scriptures, God commanded the plants and animals to reproduce after their own kind. This means that they cannot be related by common descent, nor can their posterity become a different kind. Further, the inability of different species to interbreed--and the usual sterility of hybrids--shows that this is the case.

In a previous post, The Kind of Thing Not Found in Scripture, I made several points, three of which I will summarize here:

1. Although the claim is often made that the scriptures say that animals and plants are to reproduce after their own kind, the phrase "their own kind" never occurs in the scriptures. Rather, the earth or waters are commanded to bring forth various animals "after their kind."

2. Just a few chapters following the Creation in Genesis, the story of the Flood also refers to 'kinds' of animals, including "all the cattle after their kind." It is clear in this context that the term 'kind' is used to include similar varieties. In other words, Noah isn't gathering up platonic forms, he is gathering up varieties of cattle, fowls, etc.

3. In my opinion, interpreting the creation accounts to mean that God created platonic forms that were to reproduce but remain forever unchanged (within whatever parameters define a 'kind'), requires the imposition of assumptions on the text, since the text doesn't actually say anything about kinds remaining unchanged. I think a more conservative interpretation--with respect to the text--is simply that God commanded the earth and water to bring forth a variety of beasts, cattle, fowls, fish, etc, with the animals named serving as representative examples. No process or method is specified; God simply commands the desired outcome and it occurs.

Moving on, we should recognize that this issue arises at least partially because of our propensity to categorize things, as well as our heritage from Plato. As Richard Dawkins explained in The Ancestor's Tale (p.308):

Ernst Mayer, distinguished elder statesman of twentieth-century evolution, has blamed the delusion of discontinuity - under the philosophical name of Essentialism - as the main reason why evolutionary understanding came so late in human history. Plato, whose philosophy can be seen as the inspiration for Essentialism, believed that actual things are imperfect versions of an ideal archetype of their kind. Hanging somewhere in ideal space is an essential, perfect rabbit, which bears the same relation to a real rabbit as a mathematician's perfect circle bears to a circle drawn in the dust. To this day many people are imbued with the idea that sheep are sheep and goats are goats, and no species can give rise to another because to do so they'd have to change their 'essence.'

There is no such thing as essence.

No evolutionist thinks that modern species change into other modern species. Cats don't turn into dogs or vice versa. Rather, cats and dogs have evolved from a common ancestor, who lived tens of millions of years ago. If only all the intermediates were still alive, attempting to separate cats from dogs would be a doomed enterprise, as it is with the salamanders and the gulls [two examples of ring species--see below]. Far from being a question of ideal essences, separating cats from dogs turns out to be possible only because of the lucky (from the point of view of the essentialist) fact that the intermediates happen to be dead.

I don't know whether the ancient Hebrews held essentialist views or not. It seems like a natural human tendency, but I would not want to underestimate the power of culture. Whatever the case, Western civilization has certainly inherited essentialism.

There are several other issues that the 'own kind' argument might be conveying and I think it is important to deal with them separately.

1. The inability of species to interbreed and hybridize is evidence against evolution because it shows that there are boundaries between kinds.

Fertile hybrids are more common in plants than animals. Nevertheless, the inability of species to interbreed is not a challenge to evolution. Rather, it is the result of evolution. Speciation is most commonly thought to occur through a process of reproductive isolation. As a simplistic example, imagine a population of mice that become separated from the rest of their species. If they remain isolated for long enough, their genetics will diverge from each other until they can no longer interbreed, and they will be considered two species.

The point here is that the barriers between species are not a logical problem nor a mystery for evolution. Further, we can turn the issue around and ask: If successful interbreeding is God's definition of 'kinds' then what are we to make of ring species, where local populations can interbreed with their neighbors, but the ends of the continuum cannot interbreed? And if God is so particular about keeping 'kinds' separated, why should hybrids--fertile or infertile--be possible at all?

2. If all life is related by common descent, then all life is of one kind. However, the scriptures speak of multiple distinct kinds.

This is equivocation because the meaning of 'kind' changes in each sentence. It's like saying that if humans are divided into tribes (e.g. the 12 tribes of Israel), then they cannot all be related because otherwise there would only be one tribe. In order to make sense of this one has to specify what is meant by 'kind' or 'tribe'. For example, bottlenose dolphins are a kind of dolphin, but they are also a kind of toothed whale, which are a kind of cetacean, which (skipping some levels) are a kind of mammal, which are a kind of animal, which are a kind of multi-cellular organism, and so on. That the scriptures speak of 'kinds' in one context does not preclude more inclusive (or exclusive) groupings.

3. Certain Church leaders have interpreted the scriptures as teaching that all life is to reproduce after its own (unchanging) kind, and as supporting evidence they have pointed out that different species do not interbreed and their hybrids are often sterile. Therefore, that is what those scriptures mean.

If the most important factor in accepting this general argument is that it has been promoted by some Church leaders, then the ground has actually shifted to a faith-claim. The evidence and reasoning for or against this interpretation of scripture becomes irrelevant when a person stakes out their position as a faith-claim, which they are free to do.

None of this is to argue that the creation scriptures actually endorse evolution. The expectation that science and the scriptures should match up is called concordism. However, there are reasons to reject concordism, and when it comes to the creation accounts I tend to (which makes the points I have laid out above somewhat superfluous). Rather than explain this, I invite interested readers to peruse posts with the label scriptural concordism. If you read nothing else, please read Genesis in Context, Comparing Creation Accounts, and Rejecting Concordism.

In summary, the plant and animal 'kinds' of the creation accounts are only in conflict with evolution if one holds to rigid essentialism and scriptural concordism, with a dash of scriptural inerrancy.

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Happy 200th Birthday, Lincoln and Darwin!

Today is the 200th birthday of Abraham Lincoln and Charles Darwin. In remembrance of both men, here are a few of Darwin's words on slavery.

"On the 19th of August we finally left the shores of Brazil. I thank God, I shall never again visit a slave-country. To this day, if I hear a distant scream, it recalls with painful vividness my feelings, when passing a house near Pernambuco, I heard the most pitiable moans, and could not but suspect that some poor slave was being tortured, yet knew that I was as powerless as a child even to remonstrate. I suspected that these moans were from a tortured slave, for I was told that this was the case in another instance. Near Rio de Janeiro I lived opposite to an old lady, who kept screws to crush the fingers of her female slaves. I have stayed in a house where a young household mulatto, daily and hourly, was reviled, beaten, and persecuted enough to break the spirit of the lowest animal. I have seen a little boy, six or seven years old, struck thrice with a horse-whip (before I could interfere) on his naked head, for having handed me a glass of water not quite clean;
I saw his father tremble at a mere glance from his master's eye. These latter cruelties were witnessed by me in a Spanish colony, in which it has always been said, that slaves are better treated than by the Portuguese, English, or other European nations. I have seen at Rio de Janeiro a powerful negro afraid to ward off a blow directed, as he thought, at his face. I was present when a kind-hearted man was on the point of separating forever the men, women, and little children of a large number of families who had long lived together. I will not even allude to the many heart-sickening atrocities which I authentically heard of; -- nor would I have mentioned the above revolting details, had I not met with several people, so blinded by the constitutional gaiety of the negro as to speak of slavery as a tolerable evil. Such people have generally visited at the houses of the upper classes, where the domestic slaves are usually well treated, and they have not, like myself, lived amongst the lower classes. Such inquirers will ask slaves about their condition; they forget that the slave must indeed be dull, who does not calculate on the chance of his answer reaching his master's ears.

It is argued that self-interest will prevent excessive cruelty; as if self-interest protected our domestic animals, which are far less likely than degraded slaves, to stir up the rage of their savage masters. It is an argument long since protested against with noble feeling, and strikingly exemplified, by the ever-illustrious Humboldt. It is often attempted to palliate slavery by comparing the state of slaves with our poorer countrymen: if the misery of our poor be caused not by the laws of nature, but by our institutions, great is our sin; but how this bears on slavery, I cannot see; as well might the use of the thumb-screw be defended in one land, by showing that men in another land suffered from some dreadful disease. Those who look tenderly at the slave owner, and with a cold heart at the slave, never seem to put themselves into the position of the latter; what a cheerless prospect, with not even a hope of change! Picture to yourself the chance, ever hanging over you, of your wife and your little children -- those objects which nature urges even the slave to call his own -- being torn from you and sold like beasts to the first bidder! And these deeds are done and palliated by men, who profess to love their neighbours as themselves, who believe in God, and pray that his Will be done on earth! It makes one's blood boil, yet heart tremble, to think that we Englishmen and our American descendants, with their boastful cry of liberty, have been and are so guilty: but it is a consolation to reflect, that we at least have made a greater sacrifice, than ever made by any nation, to expiate our sin."


Source: Charles Darwin, The Voyage of the Beagle, Chapter XXI

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Parley's Mountains

In 1837 Parley P. Pratt published A Voice of Warning wherein he specified the condition of the Earth as originally created. Like Mary Poppins miraculously pulling a multitude of items out of her modest bag, Parley unpacked many details from a few words of scripture.

Second, We hear the Lord God pronounce the earth, as well as every thing else, very good. From this we learn that there were no deserts, barren places; no stagnant swamps, no rough broken rugged hills, no vast mountains covered with eternal snow; and no part of it was located in the frigid zone, so as to render its climate dreary and unproductive, subject to eternal frost or everlasting chains of ice.

Where no sweet flowers, the dreary landscape cheer;
Nor plenteous harvests crown the passing year:

But the whole earth was one vast plain, or interspersed with gently rising hills, and sloping vales, well calculated for cultivation; while its climate was delightfully varied, with the moderate changes of heat and cold, of wet and dry, which only tended to crown the varied year, with the greater variety of productions: all for the good of man, animal, fowl, or creeping thing; while from the flowery plain, or spicy grove, sweet odours were wafted on every breeze: all the vast creation of animated being, breathed naught; but health and peace, and joy.

On the subject of mountains, he continued:

But how far the flood may have contributed to produce the various changes, as to the division of the earth into broken fragments, islands, and continents, mountains and valleys, we have not been informed; the change must have been considerable.

John Taylor approvingly quoted this passage in Government of God. However, perhaps this passage's biggest fan was Joseph Fielding Smith, who quoted it in at least three books, and alluded to it in at least one other publication. Bruce R. McConkie re-iterated Pratt concerning mountains in Mormon Doctrine under "Restoration of All Things":

When the earth was first created all the land was in one place and there were no mountains and valleys of the kind that now exist.

Although he may not have realized it (though perhaps he did), by denying the existence of mountains before the Fall, Parley was entering into a discussion that had been carrying on in Western civilization for over two hundred years. It turns out that mountains have historically been viewed rather negatively. Up until the 17th and 18th centuries, mountains were generally (though not exclusively) viewed as warts or scars on the face of the earth because they were dangerous and forbidding, but also because they lacked classical properties of symmetry, regularity, and proportion. It was hard to believe that God would create such things, so they were often regarded as products of either God's curse following the Fall, or the Flood, and were generally ignored by artists.


In the 17th century, mechanistic theories of the earth's origin began to take root. A landmark publication was Thomas Burnet's Sacred Theory of the Earth, published in 1681. Burnet was a clergyman, but he realized that the Flood could not possibly have covered the mountains. Drawing on Descartes, he proposed that the Earth originated as a dead star, which had water at the core and a perfectly smooth surface above. As described by historian Peter Bowler [1],

"This surface was the paradise on which Adam and Eve and their children had lived. When they turned away from God, they were punished by the great flood--but the theory provided a natural explanation for this event in the form of a collapse of the crust into the waters beneath. Only irregular fragments of the original surface were left standing out of the water, forming the mountainous terrain of the present landmasses. Our punishment thus became permanent, because Noah's descendants were forced to live among the ugly and dangerous mountains (few as yet anticipated the romantic view that mountains are beautiful). In Burnet's view, we live on a ruined planet that matches our sinful state."

At the same time, Burnet found that mountains gave him a sense of awe and turned his thoughts to God. Over the next century mountains would come to be viewed as sublime, and even beautiful, and artists reflected this change of attitude in their works. With this change came a resistance to the idea that the earth was ruined, and nature became the evidence of God's power. By the time Parley wrote, the change was more-or-less complete; however, for whatever reason Parley viewed mountains as less than "very good."

To Mormons, mountains represent a place of refuge and safety, as well as a sacred place of God's presence, either because temples have been built among them, or because in scripture they have served the function of temples on occasion. I don't know how President Smith and Elder McConkie reconciled their view of the non-creation of mountains with that depicted in the endowment, where God specifically commands the formation of mountains as an element of beauty. Parley P. Pratt wrote before the endowment existed, and I speculate that the explicit mention of mountains was added after the saints made their home among them. Whatever the case, all of this serves to remind me that although we are a restoration movement, we are still tied to our culture, which includes the culture and traditions of mainline Christianity, and that can affect how we interpret scripture.

References and Notes:

1. Bowler, Peter. Evolution: The History of an Idea, p. 32.

For more on the changing perception of mountains, see Marjorie Hope Nicolson's Mountain Gloom and Mountain Glory, which I can only claim to have browsed on Google Books.

For one brief treatment of Thomas Burnet (of many on the internet), see here.

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FARMS Reviews "The Case for Divine Design"

The Case for Divine Design: Cells, Complexity, and Creation, by Frank B. Salisbury, is reviewed in the most recent FARMS Review (2008, Volume 20, Issue 1). The review article is "The Clockmaker Returns," by James L. Farmer. Dr. Salisbury is an emeritus professor of plant physiology, and Dr. Farmer is a BYU emeritus biology professor.

I have read The Case for Divine Design completely through once, mostly through a second time, and bits and pieces even more. I think the review is pretty straightforward and even-handed, and I generally agree with it. My one quibble is that toward the end Dr. Farmer seems to see Intelligent Design (ID) as only associated ("guilty by association") with Creationism. However, the fact is that ID grew out of creationism in response to court decisions that prevented the teaching of creationism in public schools.

Now for some of my own comments on The Case for Divine Design:

The main point of the book is to argue that science does not disprove God--not that there is scientific evidence for God (Salisbury rejects ID as legitimate science), but that the history of life is not known in sufficient detail to rule out divine intervention. It is in that sense that he seems to feel affinity toward ID.

He describes his worldview as follows (pg 22):

My belief also includes the idea that an Intelligent Creator, God, played a critical role in this process. I have no conclusion about what that role might have been. Did he engineer the first life on Earth and then let evolution take over, as deists and others believe? Or did he intervene in other ways intelligently creating every species? My attitude is that we simply lack enough information to speculate at this time.

It comes as no surprise that science cannot refute such a position.

Although I am less attracted to ID than Salisbury (and I am repelled by the ID movement), my own view is actually quite similar. Yet in spite of that core agreement, I have a few reservations about the book. First let me say that I appreciate the thought that Dr. Salisbury put into the book. There are a shortage of public LDS-scientist role models and his effort to communicate his years of thinking to another generation is to be commended, and his arguments are worth considering.

In a different FARMS Review article that was written by Dr. Salisbury, he suggested that the authors "are so busy defending evolutionary theory that it never seems to occur to them that there might still be problems with the theory." I think I would turn that around here: Dr. Salisbury is so busy trying to find problems with evolution that he misses some of its strengths. To be clear, he assures us that he is not a "bitter anti-evolutionist," and in an interesting end note, he writes that he "was personally deeply troubled" by Joseph Fielding Smith's book, Man, His Origin and Destiny. (He later met with then-Apostle Spencer W. Kimball, who told Salisbury "that he knew little about the science...and had no personal convictions on the matter," and that President Smith's book was "not to be considered Church doctrine" [quotations from the book, which paraphrased Elder Kimball].) Nevertheless, in my opinion his treatment of evolutionary theory is incomplete, as the following two examples illustrate.

1. Adaptationism and genetic drift. Salisbury repeatedly expresses concern that plausible "just-suppose stories"--especially in regard to the power of natural selection--are accepted too readily as final explanations. You could argue that holding a provisional position (and rejecting others) based on existing knowledge and pending additional information, is not a bad thing--and science is not about achieving metaphysical certainty anyway. But that aside, he seems unaware that scientists such as Stephen J. Gould have made similar criticisms. Probably the most famous example is a paper Gould and Richard Lewontin wrote in 1979 called, "The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme," in which Gould and Lewontin argued for a pluralistic approach to evolution that does not entail explaining every detail in terms of natural selection.

This is relevant because Salisbury seems unaware of a significant alternative to natural selection: genetic drift, which is where the frequency of a particular gene can become the norm (or driven to extinction) due to chance events. Imagine an animal hunted to near-extinction; that species will have restricted genetic diversity going forward. In many cases, the reason certain genes will be most frequent in the recovering population will have nothing to do with natural selection. They will be predominant simply because animals with alternate versions happened to get killed by hunters.

This failure to consider genetic drift, in turn, leads him to puzzle over what in my opinion are probably non-existent problems. For example, Salisbury seems to wonder how natural selection can account for the gene that causes Huntington's disease, which kills people in mid-life (i.e. post-reproduction). Although I can imagine a genetic scenario that could lead to the Huntington's gene being spread by natural selection, it is also quite possible that natural selection has nothing to do with it. The gene might simply have spread by chance (i.e. genetic drift). Likewise, Salisbury worries about how a selectively neutral mutation in cytochrome c can spread until it becomes fixed (i.e. present in all individuals of a population). Again, this is the domain of genetic drift, which becomes a dominant factor in small populations.

Salisbury might accuse me of spinning just-suppose stories--which I guess I am, since I haven't looked into the scientific literature concerning the evolution of these genes. However, the point is that once we release ourselves from explaining everything in terms of natural selection and turn to other established evolutionary principles, some otherwise perplexing problems evaporate. Moreover, scientists have devised various statistical tests for differentiating between natural selection and genetic drift.

2. Genetic relatedness. Before genes were understood to be coded by DNA, copies of which are inherited by offspring, evolutionary relationships were determined primarily by comparative anatomy. In the second chapter Salisbury uses a literary device to express his internal deliberations and pondering by putting arguments in the mouths of "the Biologist" and "the Skeptic." The Biologist discusses the relationships inferred by anatomy and the fossil record, but the Skeptic argues (at least twice) that anatomical similarities do not prove genetic relatedness. Inexplicably, the Biologist never points out the evidences of genetic relatedness! The closest we get is a brief treatment of an evolutionary tree generated from cytochrome c sequences in the fourth chapter. He writes:

The conclusion is that, because humans and chimpanzees have identical sequences, they must be closely related, while humans and higher plants must be distantly related, since they have the fewest sequences in common. Stories such as this are compelling and are among the most impressive and plausible evidences that an evolutionist can produce, which is not to say that an Intelligent Creator could not have designed things that way.

This is quite unsatisfactory. Genetic sequences contain treasure troves of evidence suggesting common descent and genetic relatedness, and by and large the inferred relationships match those that were previously determined by comparative anatomy. He may be correct (for now) that we cannot demonstrate a genetic relationship between us and other hominans (for lack of surviving genetic material to study), but if the genetic trail goes cold at Homo erectus, it gets rather hot again with chimpanzees and gorillas. A genetic relationship with a cousin implies a genetic relationship with a common grandparent, even if the exact identity of the parents or grandparents remain uncertain.

In summary, I think that The Case for Divine Design makes some interesting points that are worth considering. However, in the examples I have discussed, as well as some I have not, I think the book raises needless doubt as to why evolution is the central organizing principle of biology. Given the wide range of material that the book covers in so short a space, readers should use the book as a springboard rather than an ending point.

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In Praise of FAIR

I've been meaning to do this for a while, but I just want to praise FAIR for their handling of DNA evidence in the dust-up over Rodney Meldrum's alternate geography of the Book of Mormon. Specifically, it warmed my heart to see a forthright defense of molecular clock. (I also appreciated their treatment of haplogroup X).

The idea of a molecular clock is simple enough: If you can determine how often mutations occur on average, then given differing sequences you should be able to estimate how long ago those sequences diverged from one another. Unfortunately it is more tricky than that in practice. About 10 years ago one study using mitochondrial DNA (mtDNA) turned up a problem with dating the most recent common ancestor (MRCA), sometimes called 'mitochondrial Eve,' when it came up with a date of 6,500 years ago.

However, there were a number of problems with this estimate and the method behind it, and using better methods mitochondrial Eve is currently estimated at about 150,000 to 200,000 years ago. But as you might expect, creationists seized upon the finding as evidence supporting the Ussher chronology of the Bible. Never mind the fact that it didn't hold with all groups of people and disagrees with radiometric and other forms of dating, as well as molecular clock dating of the X and Y chromosomes, creationists have accused scientists of rejecting the six thousand-year figure simply out of bias against the Bible--an accusation that Rodney Meldrum apparently agrees with.

So thank you, FAIR, for explaining and defending the science.

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