100 Reasons the Earth is Old (reblogged from Age Of Rocks)

I am posting this page from Jonathan Baker’s Age of Rocks here for several reasons. It is an extremely useful resource, well researched and well-written; the author addresses creationists with humanity and respect, even as he demolishes their position; and the author himself is a committed Christian (why that should matter to me, a free-thinking atheist, is something I explain below).

Siccar Point. Horizontal Devonian sandstone over uptilted Silurian greywacke. Click and re-click to enlarge

The evidence presented ranges from tree rings to topography to sedimentology to physical geography to archaeology and anthropology to geochemistry to the fossil record to radiometric dating to astrophysics. Many of these are topics I have touched on, for example in my discussions of the unconformity at Siccar Point, and the slowly cooled multiple lava flows and palaeosols of the Giants’ Causeway.

In each case, the reasoning is briefly described, with links to more detailed discussions, many framed specifically to refute creationist claims. By relegating those claims to second place, the author avoids the common mistake of teaching the very error that he is warning against. At the same time, he pays a respectful attention to his opponents, for reasons that he explains elsewhere in his blog, even as he dismantles their arguments.

Like the authors of EvoAnth  and Leaving Fundamentalism, the author is at present a graduate student; welcome examples of how the web is democratising discourse, and how young scientists and educators are using the opportunity.

I commend this piece to all those who have to deal with creationism in schools and elsewhere, alongside such classics as 29+ Evidences for Macroevolution and Index to Creationist Claims, and hope that the author will continue to update and add to it as his own career progresses.

Giants’ Causeway: interbasaltic laterite palaeosol between lava flows at The Chimneys. Click and reclick to enlarge

Like Dennis Venema at Biologos and Robert Wiens at Radiometric Dating – A Christian Perspective, the author is a committed Christian, thus helping to give the lie to the claim

Why I do NOT “believe in Darwin’s theory of evolution”

Fact not theory; 150 years on from Darwin’s watershed publication; evidence not belief. Words matter.

A recent Harris poll asked Americans “Do you believe in Darwin’s theory of evolution?” Others more eminent have commented on the answers; I would like to comment on the question.

Darwin, of course, never used the word “evolution,” but let that pass. As for the rest, it would be difficult to cram a larger number of serious errors into so small a space. Errors of presentation, of logic, and of scientific and historical fact, all of which play into the hands of our Creationist opponents.

Start with the obvious, the word “theory.” In common language a theory always involves speculation. In academic discourse, it means a coherent set of ideas that explain the facts. Calling something a theory in this sense tells you nothing at all about how certain it is. A theory can be wrong (phlogiston theory), known to be approximate from the outset (ideal gas theory), very close to the truth but since improved on (Newton’s theory of planetary motions), or as certain as human knowledge ever can be (number theory in mathematics). Of course you can explain all this, but you should not put yourself in such a vulnerable position in the first place. It wastes time in debate, or in the classroom. It puts you on the defensive, and thus, paradoxically, confers legitimacy on the attack. It allows the focus to shift from what we know about the world to the words we use to talk about it. This takes us away from science to the domain of the philosophers, lawyers, and expositors of Scripture who are fighting on behalf of Creationism.

And so it distracts from what you should be talking about, namely the facts. Evolution, whether we mean changes in the genetic make-up of populations over time, or the common descent of living things on earth, is a fact. It is supported by, and explains, innumerable more specific facts concerning the fossil record, molecular phylogeny (the same kind of evidence that is used every day in DNA paternity tests), the frozen-in historical accidents of organs that have lost or changed their function, the distribution of species throughout space and time, and much more besides. Creationism cannot explain these facts, except by appeal to the whims of the Creator.

Next “Darwin’s.” Darwin did indeed have a theory, as independently had Wallace, which was that different species had arisen gradually by natural selection operating on variation. This he supported by meticulous observation, but the range of evidence available to him was far more limited than what we have today. He lamented the poverty of the then known fossil record, laments that Creationists echo to this day as if nothing had changed. He knew nothing about mutations or even about the existence of specific genes, and so he had no idea how new variants could arise and spread. His assumption of gradualism is in contrast to later ideas such as punctuated equilibrium, and we now know that much if not indeed most variation arises through neutral drift. Thus not only do we know far more facts about evolution than Darwin could have dreamt of, but our theories, too, incorporate numerous additional concepts.

Finally, worst of all, “believe in.” Believing always carries with it the feeling that disbelief is an option. Some members of the jury believe the witness, others don’t. Some people believe that Hillary Clinton will be the next President of the United States, but no one would say they “believe” that Barak Obama is the current incumbent, because no sane person doubts it. I don’t “believe in” atoms, or gravity, or quantum mechanics, because I regard them as established beyond dispute, although our notions about them will no doubt continue to change as we learn more. And exactly the same is true of evolution.

Does it matter? Yes, it matters enormously. Creationists often maintain that evolution and Creation are both beliefs, whose respective advocates differ, not about observable facts, but about how those facts are to be interpreted. They obsess about Darwin, referring to evolution as “Darwinism,” and to those who accept this reality as “Darwinists.” The aim here is to bypass 150 years of experimental and intellectual discoveries, to bog us down in the day disputes of the late 19th century, or even (“Darwin’s doubt,” see here and here) to enlist Darwin himself as an unwitting ally.  And they contrast evolution, as “only” a theory, with facts or even with scientific laws, in order to claim that it is far from certain and that different views deserve a hearing.

Most people have not thought long and hard about evolution. And in the US at least, much of what they have heard about it will have come from its theologically motivated opponents. These opponents, whether through “statements of faith” that make obscurantism a virtue, or through “academic freedom bills” that disguise telling lies to children as open intellectual debate, use carefully crafted words to stake spurious claims to the moral high ground.

We should not, ourselves, be using words that help them do this.

Bears, whales, God, Darwin, and Peter Hitchens (Part I)

Can bears turn into whales? Peter Hitchens (PH) asks this question in two successive instalments of an anti-evolution tirade of the kind that gives ignorance a bad name. Normally I would not have bothered with such nonsense, especially since Jerry Coyne at WEIT has already dismembered what with PH passes for reasoning in greater detail than it deserves. However, PH does raise an interesting question or two, and makes one assertion is so breathtaking in its combination of arrogance and ignorance that I cannot forbear from discussing it. Let me deal with these matters in turn.

The first question is, can bears turn into whales? The suggestion is based on a remark by Darwin, in the first edition of On the Origin of Species, which he dropped it in later editions as being too speculative. However, PH still chooses, over 150 years later, to cite it as evidence that Darwin’s whole research programme, and by implication the entire structure of the life sciences as they have developed since that time, is really very silly. As to why we all indulge in such silliness, PH’s answer, which I will analyse later, is as ridiculous as it is insulting.

The answer to the question, by the way, is no. Of course, no presently existing species is capable of evolving into another presently existing species, any more than PH is capable of evolving into his late lamented brother, nor would Darwin ever have suggested such a thing. If we rephrase the question a little more precisely, do bears and whales share a relatively recent common ancestor, the answer is still no. Bears do in fact share a relatively recent ancestor with seals and walruses, but their last common ancestor with whales was back in the Cretaceous.

The obvious question then arising is this: if whales are not related to bears then what are they related to? Forty years ago, we didn’t have a precise answer to that question. Now we do, and PH could have found it easy enough, just by looking up whale evolution in Wikipedia. And while PH is understandably concerned about erroneous assignments, since the only fossil he seems to know about is the Piltdown forgery, Wikipedia will also provide him with a list of 43 separate extinct families of precursors of modern whales. But perhaps PH is a Wikipedia snob, or perhaps these articles, replete as they are with terms like “artiodactyl” and “cladogram”, are above his technical reading level. In the latter case, I would refer him to an excellent National Geographic article; in the former to either of two recent but more technical reviews, here and here. I will be writing about whale evolution at much greater length elsewhere, showing as it does a beautiful coming together of three separate lines of evidence; from the fossil record sequence, from anatomical homologies, and from molecular phylogeny.

My point here is a rather obvious one. PH admits that he is ignorant about evolution. Nothing to be ashamed of there. After all, he is a busy man, and has his own priorities, and if he can’t find the time to learn what kind of place the natural world is, and how we fit into it, then that’s his own business. But what he should be most deeply ashamed of, is his decision to write, not once but twice, about such a subject without first bothering to inform himself.

Despite his self-proclaimed ignorance, PH claims to have penetrated the motivation of the scientific community in its acceptance of what he describes, in rather simplistic and old-fashioned language, as “the theory of evolution by natural selection.” What he tells us of this theory is that the motivation is fundamentally theological, or rather, anti-theological. To quote, “I will re-state it, yet again. It is that I am quite prepared to accept that it may be true, though I should personally be sorry if it turned out to be so, as its implication is plainly atheistical, and if its truth could be proved, then the truth of atheism could be proved. I believe that is its purpose, and that it is silly to pretend otherwise.” [My emphasis]

So this is a clear statement of what PH considers to be the purpose of the theory; not to make sense of nature, as we scientists pretend, but to prove the truth of atheism. Well, questions of motivation are always interesting, if difficult to settle, but in this particular case we happen to be in a position to decide the truth or otherwise of PH’s claims. The theory of evolution by natural selection was first clearly formulated by two separate individuals, initially working independently, Alfred Russel Wallace and Charles Darwin. We know a great deal, in both cases, about their attitudes to religion, and Darwin in particular has left us a detailed description of how his views changed over time, as a result in large part of the evidence that he collected while developing and testing his theory. Both these great scientists changed their opinions on religious and spiritual matters during their working lives. Neither developed their theories in pursuit of a theological agenda, and if they had done so, that would have amounted to professional malpractice. The reality is very different, much more interesting than anything PH could have imagined, and we will return to this in the next part.

Nonsense from Nagel, and the myth of “common sense”

The appearance of Nagel’s assault on evolutionary science, Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature Is Almost Certainly False, from a position of self-confessed ignorance regarding the underlying science, prompts me to post what I wrote about his methods a few years ago (note BTW the giveaway description of 21^st Century science by a mid-19^th Century label):

Common sense or utter nonsense?

“Sophisticated members of the contemporary culture have been so thoroughly indoctrinated that they easily lose sight of the fact that evolutionary reductionism defies common sense. A theory that defies common sense can be true, but doubts about its truth should be suppressed only in the face of exceptionally strong evidence.” (Thomas Nagel, Philosophy & Public Affairs 36, 187-205, 2008; posted on FaceBook by Glasgow’s very own Centre for Intelligent Design)

It is difficult to see how one could cram a larger number of logical errors into so small a space.

We begin with an extraordinary smear on the writer’s opponents. The well-informed are labelled “sophisticated”, while to be convinced by the evidence is to be “indoctrinated”. And so, by a populist inversion, the near unanimity of informed opinion in support of evolution becomes an ad hominem argument against it. The suggestion that doubts are “suppressed” is another gratuitous smear, based on pretended ignorance of the robust reevaluation to which all scientific theories are continually exposed.

Reductionism is not defined in Nagel’s paper (in fact, the passage quoted is the only place where the concept is used), so I don’t know how he is using this notoriously slippery word, nor why purported explanations in terms of intelligent design (the proffered alternative) escape this fate, if indeed they do. However, it is worth pointing out that evolutionary explanations by their very nature describe the behaviour of systems, or even (if we restrict ourselves to the last billion years or so) of interlocking populations of systems, the very opposite of reductionism. I find it shocking that a philosopher of mind, of all people, should be unaware of this.

Worst of all is the appeal to common sense. Common sense is an amalgam of received and unquestioned wisdom, unexamined and often unconscious philosophical assumptions, and extrapolations from everyday experience. What appears to be in accord with common sense must depend on how much one already knows. Thus separate creation of kinds may appear to be in accord with common sense to someone who is completely ignorant of the richness of the fossil record, its relationship to the classification of modern organisms from Linnaeus onwards, the reappearance of the same Linnaean patterns in family trees based on molecular phylogeny, and the overwhelming evidence of the antiquity of the Earth. To someone familiar with these things, it will be the concept of separate creation that violates common sense.

Nagel does not tell us what he would regard as “exceptionally strong evidence”, just as he does not tell us what counts as “evolutionary reductionism”, but the evidence for evolution is presumably strong enough to persuade him to renew his annual flu jab. Since he is writing in a journal concerned with public affairs, it is also worth pointing out that it is strong enough to have led to changes in public policy on the use of antibiotics and pesticides, so as to avoid encouraging the (reductionist?) evolution of resistant strains.

However, the appeal to common sense is an intrinsically weak argument for other, much deeper, reasons. Common sense is an appeal to common experience. Much like the “intuition” discussed in Bertrand Russell’s essay, Mysticism and Logic, it is within the domain of common experience that it has the greatest credibility. Common sense tells us that we are standing still on solid ground, that animals and vegetables are different kinds, that space is Euclidean, that the heavens are unchanging, that an object will eventually come to rest if no force is acting on it, and that tables are solid. That the earth is moving, and that the continents themselves are moving across its surface, that a man shares half his genetic information with a mushroom, that matter distorts the space around it, that the universe is expanding, that a moving object will continue along its trajectory until something stops it, that matter is made up out of atoms and that almost all the mass of these atoms is crammed into a tiny nucleus less than one billionth of the total volume, all of these are violations of common sense. Nonetheless, they are fundamental facts of which any educated person should be aware, even at the cost of being described by Professor Nagel as “sophisticated” or, worse yet, “thoroughly indoctrinated”.