Monday, 28 May 2007

Pastor Bob blogs on the Creation Museum

I've been looking through The Creation Museum, a carnival organized by PZ Myers at Pharyngula. He has collected reactions to the new Creation Museum from all over the blogsphere, and put them together in a handy index. I have my own humble contribution, on Jurassic Pigeon at the Creation Museum! I was also looking though all the blog reactions...

Here's an interesting one: Oh My, it's time for the Creation Museum to Open, from the personal blog of Bob Cornwall: "Ponderings on a Faith Journey".

Bob is a Christian. He's the pastor of First Christian Church (Disciples of Christ) of Lompoc. He's also a journalist; which is to say he has a regular newspaper column in the Lompoc Record plus a substantial body of other articles. He is an active supporter of The Clergy Letter Project, which is all about clergy speaking up in support of teaching evolution. As of May 25, there are 10,640 signatories.

Here's an extract from the letter:
We the undersigned, Christian clergy from many different traditions, believe that the timeless truths of the Bible and the discoveries of modern science may comfortably coexist. We believe that the theory of evolution is a foundational scientific truth, one that has stood up to rigorous scrutiny and upon which much of human knowledge and achievement rests. To reject this truth or to treat it as "one theory among others" is to deliberately embrace scientific ignorance and transmit such ignorance to our children. ...

Bob wears his heart on his sleeve. If you want to check out what he thinks, you can follow the links and read his columns, sermons, blogs, and various other papers. I was particularly struck by a remark in an article he wrote about homosexuality. It was not the issue of sexuality that struck me most, but the practicalities of how science and faith interact for him:

... Overwhelming scientific evidence has shown that homosexuals are born, not made. Now I had to face the question: if the science is right, how should I as a Christian respond to my gay and lesbian brothers and sisters? I must confess I’ve not figured everything out yet, but I know that I can no longer believe as I once did.

This echos a comment made by the Dalai Lama (with my emphasis).
At one point I became particularly intrigued by an old telescope, with which I would study the heavens. One night while looking at the moon I realized that there were shadows on its surface. I corralled my two main tutors to show them, because this was contrary to the ancient version of cosmology I had been taught, which held that the moon was a heavenly body that emitted its own light.

But through my telescope the moon was clearly just a barren rock, pocked with craters. If the author of that fourth-century treatise were writing today, I'm sure he would write the chapter on cosmology differently.

If science proves some belief of Buddhism wrong, then Buddhism will have to change. In my view, science and Buddhism share a search for the truth and for understanding reality. By learning from science about aspects of reality where its understanding may be more advanced, I believe that Buddhism enriches its own worldview.

One of the topics I have tackled here at Duas Quartuncias that has provoked a bit of lively response has been my approach to moderate religion. Rather than try and explain myself again, I'll try using Bob as an example.

My reaction here is "Good on you!". The more people like Bob who speak up from within the church, the better. Bob and I continue to differ considerably on our basic worldview. I'm a materialistic atheist. He's a Christian. In discussion forums, I'd be happy to debate or discuss with him on the relative merits of these two incompatible positions. I do engage in such debates at present. But I must admit that I have less urgency about such discussions. I'd rather keep up the pressure on his more extreme co-religionists.

Read the full post...

Sunday, 27 May 2007

Fix your Duae Quartunciae feeds

I have provided a new feed for Duae Quartunicae using feedburner. If you have subscribed to my feed... thanks very much! Please update to the new feed URI.

Duae Quartunciae also thanks an anonymous commenter for a lesson on Latin grammar. Admire the spanking new title, conforming with best practice in Latin as established over 2000 years ago. I think. Further Latin education is welcome if I have stuffed it up again.

Update added 11:22pm. If you don't know what a "feed" is, you should find out. It is basically a way of keeping track of a source of information that is continually being updated, like a blog, or a news outlet, or a comic. Such sources provide a feed, that you can aggregate with lots of other feeds, and then read as it updated. Larry Moran gives a good explanation at the Sandwalk blog... see What Is an Aggregator?, complete with instructional video.

Another update: June 9. I have fixed the Latin again, and updated this post to use the new title. I have switched from accusative to nominative case, which I am told is a better case to use in Latin for most of the contexts in which the blog name will appear.
Read the full post...

Saturday, 26 May 2007

Non Sequitur on Birds and Dinosaurs

Non Sequitur by Wiley Miller is one of my favourite comic strips. This one is May 17, 2007; but read the whole sequence from May 14 through to May 19, as Jeffery goes back in time to get a DNA sample from T-Rex, taking a chicken along as his interpreter.

(PS. Wiley is pretty clued up. I am sure he is well aware that T-Rex was not actually a direct ancestor of birds. It was a Theropod; a distinct member of the group from which birds are descended.)

Read the full post...

Jurassic Pigeon at the Creation Museum!

Inaccurate Archaeopteryx model at Creation Museum

For your amusement and entertainment I present: the Jurassic Pigeon! This model is intended to be Archaeopteryx. It was produced by Buddy Davis, for the Answers in Genesis Creation Museum, which has its Grand Opening on Monday, May 28. The image is available full size at Ken Ham's blog: "A steady diet" of AiG materials and souls saved.

For all you real biologists and paeontologists out there, please add comments for this article! I'm going to describe some funny features of the model, but I know I am missing more details. If you have any expertise, or if you want to try out your amateur knowledge, please help. I think also that this model was featured in someone else's blog or article, and I have not been able to find it. Please give the link so I can credit you as well.

More information about Archaeopteryx in a nicely accessible form is available from talkorigins at All About Archaeopteryx. This is now a bit dated, but good for specifically refuting creationist confusions.

I have a relevant previous blog article on The Evolution of Wings.

There are many other pages on this famous fossil. See pages at Enchanted Learning, or at Berkeley Museum of Paleontology, or at Wikipedia.
Davis' model looks a lot like a large pigeon, with two exceptions. Davis has added the claws on the wings, and given it a tail – both valid features of Archaeopteryx.

But the head! What a mess! Archaeopteryx did not have a beak. Its head was that of a small dromaeosaur, with a dinosaur snout well supplied with teeth. The neck in Archaeopteryx, as in dinosaurs, attaches to the skull from the rear. Davis has mounted the head with the neck attaching from below, as in modern birds. Archaeopteryx has nasal openings at the end of the snout, like a dinosaur. Davis has a beak. Here is a side by side comparison with the model at the Oxford University Museum of Natural History.

The head is the funniest part of the model, but the legs are also pretty bad. Archaeopteryx had quite long legs, and well equipped with feathers. Indeed, there is a possibility that the flight of Archaeopteryx used its legs in flight as well as forearms; unlike birds that use only the arms. (cf Science News online, Sep 23, 2006.) Davis seems to have put spindly little bird legs onto the model, that vanish up into the thick nest of feathers around the body. The reality is that Archie had prominent and muscular legs, with their own feathers.

And of course the body of Davis' model is a nice plump pigeon. Archie was a predator, lean, mean, and fast.

For comparison, here are some more credible reconstructions of Archaeopteryx. Each one is linked back to the source.

Wikipedia on Archaeopteryx

There has recently been some interest in the feet of Archaeopteryx. It has been traditional that reconstructions have given Archie a fully reversed hind toe. Birds use this structure for perching, and though it is hard to see on Davis' model, he seems to have this bird like foot.

In fact, Archie's feet were much more like those of a theropod dinosaur, with a hyperextended toe complete with killing sickle claw. There's a discussion at Earliest Bird Had Feet Like Dinosaur, Fossil Shows (National Geographic News, Dec 2005) which in turn refers to "A Well-Preserved Archaeopteryx Specimen with Theropod Features", by G. Mayr, B. Pohl, D. S. Peters, in Science Dec 2, 2005, Vol. 310, Iss. 5753; pp. 1483-6.

This paper describes a number of features of Archaeopteryx apparent in the tenth known fossil. The basic conclusion, apparent in the title, is that Archaeopteryx has a lot of features linking it to theropod dinosaurs. The paper includes a detailed consensus tree of relationships, consistent with the widely accepted notion that Archaeopteryx was a sister group to modern birds. The tree identifies a group "Paraves", which divides into two groups. One includes Archaeopteryx and Rahonavis; the other is marked Deinonychosauria, which then splits into Troodontidae and Dromaeosauridae. The latter includes animals like Velociraptor, made famous by the Jurrasic Park movie. And that is the group most closely related to modern birds. *

Creationists can't handle this consistently. There are basically two responses. One set of creationists treat Archaeopteryx as a bird, with some minor differences like claws on the wings and teeth in the beak. The other approach focuses on the fact that Archaeopteryx is not directly ancestral to modern birds, and spins that into a denial of any association at all. Both arguments are symptomatic of a stolid cement headed stupidity.

The former approach manages to plumb slightly deeper depths of idiocy. Predictably, this is the approach chosen by Answers in Genesis, for their absurd museum.

Update. This article is part of a blog carnival on The Creation Museum. Go check it out; 75 differents links with brief extracts, all about this fantastically absurd museum. Thanks to PZ Myers for the hard work of putting it all together, and for the imeptus to write my own article on the subject. I have also fixed a broken link to the talkorigins archive.

* Update, May 29. The phylogeny proposed by Mayr et al., which I cited above, is contentious. A recently published phylogeny is available at A new look at the Phylogeny of Coelurosauria (Dinosauria: Theropoda) by Phil Senter, in Journal of Systematic Palaeontology, doi:10.1017/S1477201907002143, published online May 14 2007. This supports the more usual view that Aves, including Archaeopteryx, is a monophyletic group that does not include Troodontidae or Dromaeosauridae. The combined group is called Paraves, a taxon named in 1997. Locating a few well known dinosaurs within Senter's phylogeny gives the following relationships.

I'd appreciate any further details or corrections or concerns with the material I have presented.

Read the full post...

Friday, 25 May 2007

What kind of atheist am I?

What the heck; I'll play. I'll say some more useful things about my unbelief on my own behalf sometime; for the time being here is my quiz result. Compare with my friend and nemesis superlatively scientific PZ Myers (hat tip) or my friend and hero the profoundly philosophical John Wilkins (hat tip).

You scored as Scientific Atheist, These guys rule. I'm not one of them myself, although I play one online. They know the rules of debate, the Laws of Thermodynamics, and can explain evolution in fifty words or less. More concerned with how things ARE than how they should be, these are the people who will bring us into the future.

Scientific Atheist


Militant Atheist




Spiritual Atheist




Apathetic Atheist


Angry Atheist


What kind of atheist are you?
created with

I'm apparently much less scientific than PZ or John. Hm...
Read the full post...

Wednesday, 23 May 2007

Should we promote tolerant religion?

There's an interesting essay at Positive Liberty: While Europe Slept, by Jonathan Rowe. It made me stop and think. I'm an advocate for peaceful co-existence with religion; and have debated this up and down the blogs in recent times along with lots of other opinionated folks with diverse notions of how we relate to religion and to religious believers. The author of the above essay also advocates the gentle conciliatory approach, but with a bit of a twist.

You may want to read Jonathan's essay first, and then come back here to see what wisdom I can add. Because -- despite being a milk and mildness atheist myself -- I can see scope for my more hardline "new" atheist colleagues to use the same evidence Jonathan submits to argue for a negative effect of mild tolerance.

Jonathan adds a wrinkle to the notion of tolerance. He proposes that the founding fathers of the USA had a conciliatory approach to religion in which they deliberately promoted a notion of "authentic" religion that was consistent with their own secular ideals of liberality and tolerance. No matter that the actual divines of the time were still burning heretics and seeking to promote their notion of "right" religion with all the possible force available... the founding fathers deliberately chose to single out and promote forms of religion that were "compatible with liberal democratic, secular, pluralistic norms".

Jonathan proposes that we should be doing the same thing right now, with Islam. That is, in talking about Islam we should at every opportunity emphasize that "authentic" Islam is a religion of peace. As he says in the essay:

Whenever I criticize the more extreme elements of Islam, I always stress that most Muslims say this doesn’t represent the authentic version of their faith. Now, in truth, I have no idea whether I’m right and may well be engaging in a Straussian lie. But, if Islam, as a faith, isn’t going away — and I don’t think it is — Muslims must be convinced that a more liberal, sober and rational understanding of their faith is the authentic one. This is exactly what Madison tried to do with Christians in his Memorial and Remonstrance.
Can we identify a scientifically convenient authentic religion?

As I read this, I immediately thought of the ways in which we atheists approach religion. It's a hot topic in the blogsphere -- is religion the enemy of science? Or is religion (the "right" religion, of course) compatible with science?

The hardline approach is that religion and science are implacably opposed. Individuals may find a personal reconciliation; but only at the cost of their own personal consistency. It's an uneasy truce between opposing forces, and it invariably means that theists descend into unscientific nonsense at some point in this alleged reconciliation.

The conciliatory approach -- mine -- is that religion itself is consistent with science; though of course there are individual believers (creationists, for example) who hold views that are unambiguously falsified by the findings of scientists. But we tend to say that science is a process for finding things out, and that it can't find out everything. We tend not to think of science as requiring a belief in metaphysical naturalism, even though most of us actually do seem to be metaphysical naturalists -- disbelievers in God and in the supernatural. No matter; we admit that some of our scientific colleagues may have radically different metaphysical perspectives; and as long as they don't try to bring in the supernatural as a way of distorting the actual methods of scientific investigation, we don't mind what they believe. If you really can form your beliefs in such a way as to avoid being directly falsified by a line of empirical evidence, then you can be consistent with science.

Now there's something to be said for the notion that we are promoting as "authentic" a form of religion that is highly unusual and quite distinct from traditional religion all down the ages. It's not quite a total humbug, because religion does change over time; and there are plenty of religious leaders trying to promote an expression of their religion that remains fully consistent with all the discoveries of modern science. We tolerant atheists approve and encourage them.

But what if we succeed?

What will be the result? In the short term, I think the tolerant approach is pragmatic, and it may even succeed in making it possible for many in the churches to drag themselves out of the nineteenth century and share in the marvelous insights that are gained into our world when you look at it directly. And it seems that it worked for the founding fathers as well; modern religion (Christianity, at least) now recognizes many of the ideals of the enlightenment; ideals of human freedom and liberty and individual rights. Indeed, most Christians insist that this is "authentic" Christianity, and that the modern secular state only manages to retain such "Christian" ideals because of the beneficient influence of believers.

That's humbug. Religion has matured; and modern secular humanism has had a substantial positive effect. The process is not complete; but it's there, in my opinion.

And yet, and yet. Look at what we have today. The influence of religion on the social and political life in the USA is immense -- far greater than in other first world nations -- and it is to your detriment. Perhaps your founding fathers would have been better to discard any religious rhetoric altogether, and not be shackled with the Sisyphean task of dragging religion along with them as they built a new society.

You see, even if individuals of wisdom and circumspection manage to live peacefully with science, or with unbelievers, in each new generation this needs to be rediscovered. In each new generation, there are bound to be new believers who are intolerant, irrational and unwise. It's right there in the holy book; it is not a natural thing to impose tolerance and scientific literacy in ancient texts going right back to the bronze age.

Perhaps the USA would had avoided the problems she now has with such a substantial influence of religion on political and social life, if there had been less of a deliberate attempt to promote an improved modernized version of religion.

Here I stand, for the time being.

I'm still a tolerant atheist. I still think that religion can be compatible with science, for those believers who deliberately let all the findings of modern science inform the content of their faith.

I can't manage it myself; but I don't charge that others who find a stable reconcilation are necessarily being inconsistent. I'm not particularly concerned to persuade them to change, unless they want to engage in mutually respectful debate and discussion, in which case I will argue that there's excellent reason to think no God exists. I do aim to be persuasive for that position, though relaxed if others are not persuaded.

I am much more concerned with promoting a good education in science and history, and to that end I am happy to hold up as examples of "reasonable" religion those who do manage the reconciliation. And in this I am actively trying to influence the shape of religion in the future, despite the fact that I am not religious.

My own guess is that this is the most effective approach for addressing the problems with science education posed by creationism and other forms of pseudoscience. My own guess is that shifts in religion of this form will also tend to erode religion. There is an inertia to our beliefs. It's not easy to move them, but once they start to shift they do tend to continue to slide. It's not my objective, but it is my expectation that in encouraging a more "reasonable" religion, in the sense of one that is reconciled with the findings of science, I am also contributing to the gradual erosion of religion.

But I think I do understand the concerns of my more hardline fellow unbelievers. What do you think?

(Thanks to Bob Englehart for the cartoon. See it in his blog.)
Read the full post...

Tuesday, 22 May 2007

Duas Quartunciae on the Blogging Blues

I have more ideas for blog material than I have time to put them together. The blog has been up now for nearly a month, and it's off to a good start. I have a little to-do list of blog posts, that grows faster than the post get completed. I also have thoughts about the design and layout of the blog itself; I want to learn more about the underlying systems and put them to best possible use. And I have a real life, to which I allocate a bit of time occasionally.

Feel free to drop a comment here if you have some suggestions for what works and what does not, or what should change.

Here's an idea others may like to consider. On my sidebar I have a list of some of the posts on other blogs where I have left a comment. I spend time reading what other people are saying and engaging on their blogs. This list gives a gong to those blogs for saying something interesting, whether I agree with it or not. It might be something to consider including on your blogs as well.

More ideas after the fold: I don't like the blogger comment system at A few more html tags would be nice, and especially something for quoting a previous commenter. I'd also prefer the text box to appear on the same page as the other comments, rather than a special pop-up.

Here's a suggestion for colleagues at blogspot... put the little orange feed icon next to your feed links.

I'm thinking of getting a few pages set up at googlepages or some other hosting service, and having them linked from my blog front page, for certain kinds of information -- like a large blogroll or whatever -- that I don't think should load up everytime someone looks at my front page.

I don't know what kinds of functionality is appreciated by visitors. Technorati button, stumbleupon, or anything else. A blog can easily get overloaded with functionality like that; so what gives real added value?

As for posts, I want to have a few more of useful content. I have ideas for posts on a few simple maths topics, on some more religion/unbelief issues, on some cosmology. I'm considering a bit of a childhood autobiography which shows up some influences that continue to impact on how I do things.

I want to redesign the template of the blog, to use tags better, like the heading tags, as recommended by some of the style guides.

And what about my feeds? The standard blogger feeds seem to be missing a description of some kind. At least, they don't show up properly for Pharyngula's blog harvest systems. And should I use a full feed, or a partial feed? I'm not sure.

Suggestions, on anything, will be very welcome!

(Thanks to for the lolcat lion. Follow the link for lots more lolcats.)

Read the full post...

Sunday, 20 May 2007

One hundred books meme

To keep the blog ticking over until I get around to my next topic blog, here is a quick meme contribution. I picked this up from Grrlscientist at Living the Scientific Life. The idea is to take this list of 100 books (how was it originally chosen?) and record it with all the ones you have read in bold, and the ones you want to read in italic. The ones in which you are not interested stay unemphasized. Please check my list and draw my attention to those I SHOULD want to read, but have failed to emphasize!

I've left unchanged any I did not recognize; and this is bound to include some serious omissions. I propose that commenters should please single out any one (or more) that I SHOULD want to read!

It is also amusing to click back through the history of the meme. Grrlscientist links to her source, and you can keep going back.

1. The DaVinci Code (Dan Brown)
2. Pride and Prejudice (Jane Austen)
3. To Kill A Mockingbird (Harper Lee)
4. Gone With The Wind (Margaret Mitchell)
5. The Lord of the Rings: Return of the King (Tolkien)
6. The Lord of the Rings: Fellowship of the Ring (Tolkien)
7. The Lord of the Rings: Two Towers (Tolkien)
8. Anne of Green Gables (L.M. Montgomery)
9. Outlander (Diana Gabaldon)
10. A Fine Balance (Rohinton Mistry)
11. Harry Potter and the Goblet of Fire (Rowling)
12. Angels and Demons (Dan Brown)
13. Harry Potter and the Order of the Phoenix (Rowling)
14. A Prayer for Owen Meany (John Irving)
15. Memoirs of a Geisha (Arthur Golden)
16. Harry Potter and the Philosopher’s Stone (Rowling)
17. Fall on Your Knees (Ann-Marie MacDonald)
18. The Stand (Stephen King)
19. Harry Potter and the Prisoner of Azkaban (Rowling)
20. Jane Eyre (Charlotte Bronte)
21. The Hobbit (Tolkien)
22. The Catcher in the Rye (J.D. Salinger)
23. Little Women (Louisa May Alcott)
24. The Lovely Bones (Alice Sebold)
25. Life of Pi (Yann Martel)
26. The Hitchhiker’s Guide to the Galaxy (Douglas Adams)
27. Wuthering Heights (Emily Bronte)
28. The Lion, the Witch and the Wardrobe (C. S. Lewis)
29. East of Eden (John Steinbeck)
30. Tuesdays with Morrie (Mitch Albom)
31. Dune (Frank Herbert)
32. The Notebook (Nicholas Sparks)
33. Atlas Shrugged (Ayn Rand)
34. 1984 (Orwell)
35. The Mists of Avalon (Marion Zimmer Bradley)
36. The Pillars of the Earth (Ken Follett)
37. The Power of One (Bryce Courtenay)
38. I Know This Much is True (Wally Lamb)
39. The Red Tent (Anita Diamant)
40. The Alchemist (Paulo Coelho)
41. The Clan of the Cave Bear (Jean M. Auel)
42. The Kite Runner (Khaled Hosseini)
43. Confessions of a Shopaholic (Sophie Kinsella)
44. The Five People You Meet In Heaven (Mitch Albom)
45. The Bible
46. Anna Karenina (Tolstoy)
47. The Count of Monte Cristo (Alexandre Dumas)
48. Angela’s Ashes (Frank McCourt)
49. The Grapes of Wrath (John Steinbeck)
50. She’s Come Undone (Wally Lamb)
51. The Poisonwood Bible (Barbara Kingsolver)
52. A Tale of Two Cities (Dickens)
53. Ender’s Game (Orson Scott Card)
54. Great Expectations (Dickens)
55. The Great Gatsby (Fitzgerald)
56. The Stone Angel (Margaret Laurence)
57. Harry Potter and the Chamber of Secrets (Rowling)
58. The Thorn Birds (Colleen McCullough)
59. The Handmaid’s Tale (Margaret Atwood)
60. The Time Traveller’s Wife (Audrew Niffenegger)
61. Crime and Punishment (Fyodor Dostoyevsky)
62. The Fountainhead (Ayn Rand)
63. War and Peace (Tolstoy)
64. Interview With The Vampire (Anne Rice)
65. Fifth Business (Robertson Davis)
66. One Hundred Years Of Solitude (Gabriel Garcia Marquez)
67. The Sisterhood of the Traveling Pants (Ann Brashares)
68. Catch-22 (Joseph Heller)
69. Les Miserables (Hugo) unabridged, thank you very much!
70. The Little Prince (Antoine de Saint-Exupery)
71. Bridget Jones’ Diary (Fielding)
72. Love in the Time of Cholera (Marquez)
73. Shogun (James Clavell)
74. The English Patient (Michael Ondaatje)
75. The Secret Garden (Frances Hodgson Burnett)
76. The Summer Tree (Guy Gavriel Kay)
77. A Tree Grows in Brooklyn (Betty Smith)
78. The World According to Garp (John Irving)
79. The Diviners (Margaret Laurence)
80. Charlotte's Web (E.B. White)
81. Not Wanted On The Voyage (Timothy Findley)
82. Of Mice And Men (Steinbeck)
83. Rebecca (Daphne DuMaurier)
84. Wizard’s First Rule (Terry Goodkind)
85. Emma (Jane Austen)
86. Watership Down (Richard Adams)
87. Brave New World (Aldous Huxley)
88. The Stone Diaries (Carol Shields)
89. Blindness (Jose Saramago)
90. Kane and Abel (Jeffrey Archer)
91. In The Skin Of A Lion (Ondaatje)
92. Lord of the Flies (Golding)
93. The Good Earth (Pearl S. Buck)
94. The Secret Life of Bees (Sue Monk Kidd)
95. The Bourne Identity (Robert Ludlum)
96. The Outsiders (S.E. Hinton)
97. White Oleander (Janet Fitch)
98. A Woman of Substance (Barbara Taylor Bradford)
99. The Celestine Prophecy (James Redfield)
100. Ulysses (James Joyce)

Read the full post...

Tuesday, 15 May 2007

Explaining theistic evolution to Martians

PZ Myers has requested an explanation of the difference between theistic evolution and intelligent design. Furthermore, he suggests that we imagine he's a Martian. This is a constructive suggestion, and I shall give it my best shot. I'm not sure what Martians are really like, so I'll presume that they are like PZ.

Background on Martians, for any human readers

Martians have good understanding of the natural world, and good appreciation of the areas where we don't have answers as yet. Technologically and scientifically, Martians are pretty much at the same position as humanity. Martians are social animals; who form stable family groups, and also like to engage constructively with others of their species. They are willing to put significant time and energy into their wider society, and put high importance on the well being of their fellows. They are curious about the world and seek to learn about it, and to share what they have learned, with passion and enthusiasm.

However, Martians have no concept of religion, or of a supernatural, or of Gods. They've heard about such things, since they regularly tap into the broadcasts we humans have been making; but this is one aspect of human society that Martians just don't get. They are inclined to think that humans who believe such things are, well, "a couple of tentacles short of a full cranium".

Welcome and Introduction

Honourable Ambassador, welcome to the third planet. You are aware, of course, that humans have a range of curious notions about the nature of the world. One common belief, in which you have expressed particular curiosity, is the notion of "God", an invisible intangible powerful conscious being. The reasons people believe such a thing are many and varied. None of them are particularly good. Humans are prone, from time to time, to have strange beliefs without any good evidence. A few other examples: We were meant to be together. I can still drive just fine. This shirt brings me luck.

The diversity of human beliefs about "God" is enormous, and many of them are in direct conflict with easily confirmed common knowledge about the world. Other beliefs about God are technically consistent, in the sense that they don't seem to make any empirical difference to anything we can effectively observe or sense.

Many people believe that such a being is responsible for making the world. The term "creator" is used, suggesting that in some way the putative intangible "God" causes other more tangible things to exist in the forms we can observe. This belief in a creator takes an enormous variety of forms.

Although none of these beliefs are well founded, it has still been convenient to classify some common themes. I shall attempt to describe three, and explain the utility for these broad classifications.


This term is used for a belief that "God" used an act of special intervention to create things, in particular the universe, this particular planet, and the first living things. This belief has real substantive content (albeit ludicrous). It represents the creative act as a genuine alternative to the conventional discoveries we have made about how things were actually formed. It is common to hold that the interventions occurred comparatively recently, though there are exceptions. Creationists reject the notion that the form of living organisms, and humans in particular, can have evolved. They reject the discovery of biological evolution, the discovery that contemporary living forms developed from radically different ancestors by the agency of cumulative variation along a lineage modulated by natural selection.

Intelligent design

This is a form of creationism that has been shorn of any actual content. For political reasons they avoid explicit mention of God. In an effort to avoid refutations they avoid making any positive claims about, well, anything at all. They do reject the efficacy of natural processes and biological evolution in particular as the means by which living things take the forms we now observe, and their reasons and arguments are the same as those used by other creationists. They hold that living forms must have been "intelligently designed" instead – though they have no actual account of what that might mean. It's basically conventional creationism cut down to remove anything positive or any explicit mention of God.

Theistic evolution

The creationist position can be pared down even further, so that nothing is left except the statement that God is creator. To this, theistic evolution makes one new addition – explicit recognition of the validity of evolutionary biology. The theistic evolutionist considers that natural processes like evolution are the means by which the creator creates. How this works is unclear, and it is not something that is argued from an empirical basis.

Why distinguish intelligent design and theistic evolution?

Although intelligent design is a form of creationism, the same cannot be said for theistic evolution – at least given the ways of using terms I have described here. Creationism, including intelligent design, sees the action of God as something that is contrasted with the action of natural processes. Creationism is incompatible with evolutionary biology, because it is presented as an alterative to evolutionary biology.

Theistic evolution, on the other hand, recognizes evolution as a valid description of how living things came to have their currently observed physical forms. Theistic evolution sees God as in some sense responsible to the establishment of the evolutionary process itself; either by setting up initial conditions so as to enable evolution, or else by continuously maintaining the existence of a universe in which evolution can occur. There is no evidence for either proposition; but theistic evolution is not claimed to be a scientific model based on evidence; but rather a nebulous faith statement about some unevidenced responsibility of "God" for the ongoing operation of all aspects of the natural world.

The reason this distinction is of any interest to those who do not believe in God arises largely from a concern about science education.

Creationism, including intelligent design creationism, incorporates an explicit rejection of basic science. The cut down version of creationism called intelligent design is specifically tailored to avoid the social protections we have set up for education. Advocates for these notions are active in trying to degrade and distort science education, by inclusion of various trivially fallacious and pseudoscientific notions under the basically dishonest guise of alternative scientific models. They necessarily see the teaching of basic science as teaching a denial of their own beliefs.

Theistic evolution, on the other hand, is an unscientific add-on to conventional science. Most theistic evolutionists recognize that this add-on is not science, and do not seek to include it in the teaching of science. They do not regard the teaching of conventional science as a denial of their own beliefs.

Two design arguments

A convenient way to identify this subtle but significant distinction is to look at the perspective of the two groups on design. The arguments or apologetics given for beliefs about design and a creator come in two diametrically opposite forms.

Intelligent design and creationism claim that the natural processes studied by science are inadequate as an explanation for complex living things, and on that basis they claim that some other better explanation is required, which they label "design".

Theistic evolution considers that the natural processes studied by science are extraordinarily effective as an explanation for complex living things, and on that basis they claim that this fecundity was established by design.

One group sees design in the putative inadequacy of natural processes. The other sees design in the efficacy of natural processes.

Update: May 16 12:45. On reflection, I think the term "theistic evolution" is potentially confusing. What I really mean by that is "theism and evolution". The actual scientific descriptions of evolution remain totally unchanged. It's not a different theory of evolution; but the position of accepting perfectly conventional evolutionary biology while also being a theist. How theism can be consistent with evolutionary biology is a problem for theology, or for general theism/atheism debates. Such debates are fine by me; I engage in them also.

I was prompted to make this remark by reading these comments left at another blog, by Tyler DiPietro. I've also acknowledged below in comment #9.
Read the full post...

Monday, 14 May 2007

Gervais explains Creationism from the source

Lots of people have picked up on this, and rightly so. Very funny. An excellent comic considers creationism. I sometimes think a good belly-laugh achieves more than any of our scholarlary demolitions. Part two below the fold.

Read the full post...

Saturday, 12 May 2007

Landing an F15 with only one wing.

What do you do when a wing is torn off your F15?

If you are Captain Zivi Nedivi, of the Israeli airforce, you break off from your training exercise and return to base. You've only got one wing, but you make up for that by flying twice as fast.

This really happened, on May 1 1983, over the Negev desert. The F15 Eagle collided with an A4 Skyhawk. The Skyhawk was destroyed, though I understand that the pilot ejected automatically and survived. The Eagle had a wing torn off, but the pilot incredibly managed to regain control and return safely home.

There's a great video reenactment of this, and I've added a partial transcript of the pilot's own account. The video was made by the history channel. All the moving pictures are reconstructions of some kind, but there are authentic still photos of the F15 after landing, at the end of the clip.

I've made a rough transcript, with a few "um" and "er" omitted. Portions in italic are spoken by the pilot.

Captain Zivi Nedivi experiences a pilot's worst nightmare when a training exercise goes horribly wrong.

He is flying a simulated airfield defense mission and is tasked with intercepting hostile aircraft, when disaster strikes

I saw what in hindsight was the number three, which is the leader of the second, the rear air, and he was upside down and I was around thirteen, fourteen thousand feet and I shot a missile.

Even though he was upside down, he continued to go up, and I was like this so it was stomach to wing, we couldn't see each other, and, uh, we collided.

Big commotion, big bang. The A4 basically fireballed immediately and I found myself with maybe thirty degrees nose down attitude and the aircraft was spinning.

Right after the crash I told my navigator "Prepare to eject, we're going to eject".

I opened afterburner, which is a totally opposite instinct when you're spinning towards the ground. Then the roll slowly stopped and slowly I was able to bring the nose back up.

I told my wingman to come close and to inspect me. There was a huge spray of fuel that was being drawn out of the wing, and it basically camouflaged what was going on there.

Nedivi survives the midair collision. He is ten miles out from the nearest airfield and hopes to still land safely. The pilot cannot see what has happened behind the spray of leaking fuel. His F15 has been so badly damaged in the collision that he is flying on just one wing.


After a devastating midair collision, Captain Zivi Nedivi finds himself flying a seriously damaged F15. Somehow he is able to regain control over his aircraft, and attempt a landing.

I approached the airfield. I crossed the threshold. Where usually in an F15 you cross at 130 knots, I crossed at anywhere between 250 to 260 knots.

He was landing at approximately twice the normal landing speed.

I put the tailhook down. There was a cable at about a third of the runway, and we went into that cable. But because of the speed, the hook is not built for those speeds and the hook basically tore off the aircraft.

We stopped maybe twenty feet short of the barrier.

As I was running the last fifty knots, bleeding off, my wingman said: "You're not going to believe what you flew on."

And I opened the canopy and I reached back to shake the hand of the navigator. And as I was reaching back, that was the first time that I looked and I saw that I didn't have a wing on the right hand side.

It's highly likely that if I would have seen it clearly I would have ejected, 'cause it was obvious you couldn't really fly an aeroplane like that. I don't think any other aircraft could have taken that amount of damage or that portion of its flight surfaces removed and continue to bring us home safely.

The best testament was a good friend of mine who was an F16 pilot, and he crossed and he saw that there was no wing, and his first words was "Can I transfer to F15s?"

It should be aerodynamically impossible for an aircraft to fly with one wing missing. McDonnell Douglas sends a team to investigate the incident.

Their first inclination was it was a taxiing accident. It couldn't happen in air in the aeroplane, and only when they later went to analyse it and said: "OK. The F15 has a very wide body, and you fly fast enough and you're like a rocket. You don't need wings."

The story has been told in various other locations. Here is another widely cited article: Mission Impossible. Apparently, the aircraft was repaired, with a few new parts (like a wing, for example) and restored to active duty in two months.

I found this just mind blowing. Hope you enjoy it as well!

Read the full post...

Friday, 11 May 2007

Teach the controversy

Evolutionary biology is a vibrant field of science, and full of active dispute and uncertainty and new discovery. Science education ideally gives students the basic background so that can find their way around popular descriptions of what is going on at the bleeding edge of research.

Here are some of the controversies that could easily be part of a lesson even in high schools.

1. The Cambrian Explosion. About 530 million years ago, and over a period of some 10 million years or so, there was a dramatic diversification of animal life, the like of which has never been seen before or since. There are a host of unanswered questions and hypotheses about what is involved. When it occurred, how long it lasted, what are the antecedents, what changes took place, what mechanisms were involved. It is seen as an artefact of sampling, giving limited insight to a much more spread out period of change, or as a comparatively abrupt phase shift in the biosphere. It's seen as driven by evolution of exoskeletons, or of vision, or of predation, or of HOX genes. It is seen as driven by oxygenation, or warmer temperature, or changes in the sea floor. On going investigations continue to shed light on this fascinating period, but it's still wide open for new research and ideas.

2. Horizontal transfer verses variation through descent. For the most part, we carry within our bodies the genetic heritage of our ancestors; but there are also possibilities for genetic information to become incorporated into the genome from other organisms or a virus. This is particularly common in bacteria, but it can also occur for more complex organisms. The extent and importance of this is an open research question.

3. Particulars of lineage and relationships. There are many cases in which scientists are uncertain as to the relationships of different organisms. A classic example is the whole dinosaurs to birds issues, though this one is now all but resolved. There are plenty more that remain wide open. One example would be relationships between insectivores (insect eaters -- shrews, hedgehogs, moles, tenrecs, etc). There are many other examples.

4. Drift verses positive selection. It's a common misconception to think of evolution as a kind of continuous progress in improved fitness. Recent decades have given strong support for a notion of neutral drift, and the development of characteristics that are not adaptive, but simply a consequence of accumulated neutral change. What features of an organism actually are adaptive, or a result of positive selection? There are ways to measure this when we have access to a DNA sequence. With fossils and paleospecies it gets more difficult.

5. Target of selection. People often think they understand selection; but what is selected? Is it genes? Individuals? Populations? Species? All of these have been proposed as targets for selection, and the debate continues as to their relative importance.

6. Evolution and behaviour. We are more than our physical forms; we also have tendencies and predilections for different kinds of behaviour. To what extent is behaviour subject to evolution? This is a very difficult and contentious dispute!

7. Physical details of microevolution. There's still a lot we don't know about how development works, and how variation accumulates from generation to generation. What kinds of change can arise in the genome? Genes are far more than a coded protein sequence. They come with promoter regions and splicing points, and ways of encoding multiple proteins depending on how exons are combined. Evolution can duplicate whole genes, or combine them, or alter the regulatory promoters. Some parts of the genome are much more subject to variation than others. What kinds of variation are possible? What is their relativity frequency and importance? What proportion of variation is deleterious? How important is the piggyback effect where selection for one variation carries along other consequences? I'm only touching on the huge range of active research questions here.

I'm not a biologist. If you can educate me further in any of these or add some more, please leave me a comment!

(Disclaimer: this post is a repeat with minor revisions of something I wrote sometime ago in a discussion forum.)

Update: I omitted to say why I wrote this. It was originally given in the context of creationist notions about teaching the controversy. I intended to contrast what genuine scientific controversy looks like, as opposed to the screwy notions of creationists.
Read the full post...

Tuesday, 8 May 2007

Does Darwinian evolution support conservative values?

In a recent article, conservative USA blogger and writer Dinesh D'Souza suggests conservatives should recognize that Darwinian evolution "has a lot of evidence going for it [with] the added merit of being politically congenial" (Why Darwin Scares Conservatives, When He Shouldn't.)

In my previous blog article, I suggested that D'Souza's article is a positive step, in so far as it recognizes the validity of conventional evolutionary biology. In this followup, I propose that recognizing the validity of Darwinian evolution does not give the easy support to conservative values that D'Souza proposes.

Dinesh notes that Christian conservatives in the USA sometimes come across as yahoos, because of their rejection of Darwinian evolution. They do indeed! It's a startling comment on the failure of science education that so many people can't tell the difference between straightforward well established discoveries of science, and breathtakingly inane pseudoscience.

The major impediment to education is religious. Far too many people accept on faith certain religious beliefs that have long since been decisively refuted. For such folks, progress in basic science education requires them to revise those beliefs.

Does this require them to drop their religion altogether? Actually, no. That is one way forward, and many have taken it. There are also others who have reconciled their religious beliefs with the findings of conventional science. In the latter case, there will continue to be debate and dispute between believers and unbelievers; addressing the consistency and parsimony of their views; but it's no longer a dispute on the underlying empirical facts about how evolution proceeds.

I'm fine with that. I do debate religion, and will be posting here some positive arguments for unbelief. But I don't think this has the same urgency as basic science education. Many people find it much easier to revise their beliefs rather than to abandon their religion altogether and so Christians who accept science (like Ken Miller, for a prominent example) have an especially important role in the fight for science education.

Just quietly, I also think this is a slippery slope. It seems to me that Christians who switch away from a position of crude fundamentalism and historical inerrancy and into a more "liberal" faith are particularly prone to keep going and in time lose their faith altogether. It's not a universal rule; but once your beliefs start to move even a little bit, there seems to be some momentum involved. But I digress. I truly don't mind when Christians find a stable reconciliation, and am much more concerned to help people break free from pseudoscience than to persuade them away from religion altogether.

Dinesh proposes an interesting point of leverage. It's not merely religion that breeds rejection of science. This is especially true of politically conservative religion. But Dinesh suggests that political conservatives could, if they recognized the validity of evolutionary biology, employ that as a new basis for argument in support of conservative ideals.

If this worked, it would be a powerful tactic. Being "scientific" is impressive. A "yahoo" is less persuasive. So in this article, I'll look briefly at Dinesh's three chosen examples.

Tough Foreign policy

D'Souza considers that Darwinian evolution provides a justification for "tough foreign policy".

First, Darwin gives a dark and selfish view of human nature, which is why we need a tough foreign policy to deal with bad guys who cannot be talked out of their badness--even if U.N. cocktails are served.
This is, of course, a classic example of a superficial misunderstanding of evolutionary biology. This could be cited as a refutation of my previous blog entry, to say that D'Souza really is "redefining" evolution. I think it is better seen as a common limited understanding of evolution.

In fact, evolution can perfectly well select for altruistic and social behaviours, as well as for selfish ones. Humans are "naturally" social beings, and there's good reason to see that as a characteristic that has evolved under natural selection.

We co-operate, but we also act to "punish" those who don't co-operate with us. There has been quite a deal of research on this, and some fascinating papers. Humans are willing to make significant personal sacrifices for the sake of inflicting "punishment" on someone else who breaks norms of social co-operation; and we are also inclined to altruistic behaviours – up to a point. Both of these convey no immediate benefit to the individual; but they can indirectly contribute to the fitness of an individual within the social context of human society.

There are lots of papers on this. One example of many is "Costly punishment across human societies", by Henrich et. al., in Science 2006;312(5781):1767–70. Here's the abstract:


Recent behavioral experiments aimed at understanding the evolutionary foundations of human cooperation have suggested that a willingness to engage in costly punishment, even in one-shot situations, may be part of human psychology and a key element in understanding our sociality. However, because most experiments have been confined to students in industrialized societies, generalizations of these insights to the species have necessarily been tentative. Here, experimental results from 15 diverse populations show that (i) all populations demonstrate some willingness to administer costly punishment as unequal behavior increases, (ii) the magnitude of this punishment varies substantially across populations, and (iii) costly punishment positively covaries with altruistic behavior across populations. These findings are consistent with models of the gene-culture coevolution of human altruism and further sharpen what any theory of human cooperation needs to explain.
The appropriate way to use any theory of human behaviour as a guide to policy is certainly not to decide what is natural and then do that. We need to estimate the probable response of others to our various policy possibilities, and use that to estimate whether or not the policy is likely to have the effects we want.

That is, any model of human behaviour is a description, not a prescription. We have the capacity to reflect and decide actions, on whatever basis we choose. The role of a behaviour model is an aid to estimating the probable effects of actions, so that we can use that to help make a wise choice.

D'Souza suggests that people are bad, and cannot be talked out of bad behaviours; and so force is a better option. But in fact, evolution does not mean simply that people are bad.

I suggest that a genuine scientific investigation of human behaviour reveals a bad downside to "tough" foreign policy. If we take actions that others perceive as "unfair", then they are likely to make considerable personal sacrifices in order to punish us. But if our actions are perceived as fair, then we have a better hope of tapping into the natural human capacity for social co-operation. It's not a simple question; because there are also costs associated with actions that others might perceive as fair, and that needs to be weighed in the balance. But it's just not a valid inference of evolutionary theory to infer that "tough" policy is likely to be the most effective.


D'Souza says:
… the selfishness in human nature warrants a system called capitalism which channels this self-orientation toward the material betterment of society.
This is a massive begged question. It may be that Darwinism gives an explanation for human selfishness; but as noted above it is also consistent with altruistic behaviours. The fact is, evolution does not give a simple prediction for either selfishness or for altruism. It rather predicts that behaviour will tend to increase reproductive fitness; but what behaviour has that effect depends on the environment and interactions of the organism.

More seriously, what really needs to be argued here is that capitalism does actually channel self-orientation toward the material betterment of society, as claimed. That's what is really required for a support of the conservative position. Sorting out the causes of behaviour is not all that important; since we have the behaviours in any case, regardless of causes. Evolution does nothing to support the notion that capitalism is actually effective at channeling self-interest into material betterment of society. It's pretty clear that unrestrained unregulated capitalism has some major negative effects on society as individuals accumulate sufficient power to manipulate circumstance to their personal benefit.

Family values

D'Souza says:
Darwinian theory supplies the reason [that children are safest with their natural parents]: the real parent shares the same genes as the child and this forms a bond that dispels sexual attraction and discourages abuse. "Family values" are supported by modern evolutionary biology.
I agree that children tend to be safest in the care of their own parents; but that is a general tendency rather than a universal rule. Evolutionary theory means that there is variation in behaviour; and we see that in any case. Good parents have better evolutionary fitness; but some children nevertheless end up with the rare examples of abusive natural parents.

But more seriously, this has little to do with the wide ranging set of policies that come under the umbrella of "family values" for political conservatives.

For example, supporters "family values" typically oppose homosexual marriage. That has nothing to do with children. They oppose adoption of children by homosexuals. But the argument as given is actually against adoption altogether – except that adoption is invariably in a case where natural parents are simply not an available option. The advocate adoption as an alternative to abortion. If anything, the argument presented should suggest that adoption is NOT a good alternative; except of course that someone who insists on a right to life for the unborn will see adoption as better than death. But D'Souza's argument sheds no light there.

One feature of evolutionary theory is that there is always potential for far more children to be born than can possibly survive. So in "saving" one unborn child from abortion, one is in fact contributing to population pressure that will contribute to subsequent potential lives never being realized. This applies also on the small scale. A girl or young single woman who opts for abortion in response to an unwanted pregnancy is often likely to mature and form a stable relationship in the future where children are safer and wanted. That potential may be lost if the first pregnancy proceeds to birth. Of course, this is unpersuasive to those who only recognize potential in the context of an actual physical conception; but the Darwinian argument does not work for that position.

In brief; I'm glad to see a religious conservative speak up on the validity of conventional Darwinian evolution. I don't agree that this gives the easy support to conservative values as D'Souza understands them. But at least one level of irrationality has been (hopefully!) removed from consideration as we engage such issues.
Read the full post...

Sunday, 6 May 2007

Is D'Souza really redefining evolution?

Conservative USA blogger and writer Dinesh D'Souza isn't afraid of Darwin. According to D'Souza, this is not because Darwin can be easily refuted; but because actually Darwin is perfectly compatible with Christian belief in design. He says:

I know many on the right, especially the Christian right, are scared of Darwin. Even intellectual magazines like Commentary seem to have adopted an anti-Darwin position. This has enabled many on the left, as well as the professional atheists like Richard Dawkins and Sam Harris, to portray conservative Christians as yahoos. Sometimes we do come across that way.

In my forthcoming book "What's So Great About Christianity" I will show why, contrary to the claims of Dawkins and company, Darwinian evolution does not undermine the design argument for God. On the contrary, the latest findings of modern science have greatly strengthened that argument. Paley was right and Dawkins is wrong.
This has been picked up by a number of prominent bloggers. Pharyngula is unimpressed, at The rebranding of Intelligent Design. He says:

The new strategy is to embrace the word "evolution". Ask them if they believe in evolution, and they will happily declare that "Yes, I believe in 'evolution'!" Unfortunately, what they call "evolution" is not evolution as evolutionary biologists understand it. If they're willing to redefine science, what's to stop them from redefining mere evolution to suit them?
Pharyngula's title got it right. D'Souza is trying to rebrand design, but without letting on that this is what he is doing. But is D'Souza actually redefining evolution? Not that I can see.

Paley's notion of design

D'Souza is playing fast and loose with the notion of design. Paley's arguments on natural theology dealt specifically with the forms of living things. His famous book, first published in 1802, is Natural Theology, Or, Evidences of the Existence and Attributes of the Deity. This includes the notorious "watchmaker" argument, which is the argument that has been picked up by the modern intelligent design movement. Put simply, anything that complex needs a designer. This argument was exploded by Darwin's insights on the origin of species.

The modern Intelligent Design movement picked up the shreds of this now useless argument, and by virtue of reeking incompetence at elementary science they tried to prop up the corpse with a lot of claims about new scientific theories. No science was actually involved, of course; just lots of bafflegab, and repackaging of conventional creationist arguments. This charade has been thoroughly exposed for anyone with the wit to see it.

D'Souza thinks Paley got it right. But Paley does much more than propose design. He gives an actual argument for design, and he speaks specifically of design of the forms of living things themselves. And in this, Paley got it wrong.

For instance, on page 468 (12 ed) of his book, Paley considers some difficulties with his view.

The TWO CASES which appear to me to have the most of difficulty in them, as forming the most of the appearance of exception to the representation here given, are those of venomous animals, and of animals preying upon one another. These properties of animals, wherever they are found, must, I think, be referred to design; because there is, in all cases of the first, and in most cases of the second, an express and distinct organization provided for the producing of them. Under the first head, the fangs of vipers, the stings of wasps and scorpions, are as clearly intended for their purpose, as any animal structure is for any purpose the most incontestably beneficial. ...
The remainder of the chapter makes fascinating reading. Paley gives some mitigating considerations, and a look at the whole problem of evil, and also, interestingly, a consideration of a role for chance and contingency along with design.

The critical point to bear in mind is this: Paley is looking at the specific organs and adaptions of living things. In Paley's view, the form of such organs can only be explained by design. Darwin showed that this is wrong; finely adapted organs can also be explained by natural selection.

The modern intelligent design movement is perfectly correct to see evolution and design as being two radically different explanations for the finely adapted forms of living complexity. They can't both be right, and this design argument is most certainly wrong.

Another view of design

At this point, we come to a subtle distinction. Darwin certainly exploded the line of reasoning used by Paley, but he did not explode the conclusion that the natural world is established by the design of a deity. Darwin left in smoking ruins the best positive argument from the natural world to a deity. He did not actually proceed to refute the deity itself.

It seems hard for many atheists to get their head around this point: but there are many Christians actively at work in scientific research into the natural world, and who accept without quibble or distortion all the basic empirical facts of evolutionary biology as conventionally understood by mainstream science. Christians are a minority amongst working scientists, but there are still a substantial number.

Christians invariably have some kind of notion whereby the natural world is God's creation. For Christians active in conventional science, this usually means that evolution itself is an intended consequence of how the designer set up the cosmos. An interesting example of this perspective is the famous evolutionary biologist Theodosius Dobzhansky. Dobzhansky's well known essay,
Nothing in Biology Makes Sense Except in the Light of Evolution is actually about science and religion, and it expresses basically a kind of theistic evolution. He says:

The organic diversity becomes, however, reasonable and understandable if the Creator has created the living world not by caprice but by evolution propelled by natural selection. It is wrong to hold creation and evolution as mutually exclusive alternatives. I am a creationist and an evolutionist. Evolution is God's, or Nature's method of creation. Creation is not an event that happened in 4004 BC; it is a process that began some 10 billion years ago and is still under way.
This is a variant of a common theme amongst Christians who are active in science. They hold that the entire natural world is established by design, and that any study of natural processes is study of that design.

This perspective is, of course, not provable and (usually) not falsifiable. It is not a scientific model. This is invariably recognized by its advocates. It may not be a good fit with popular religion, but Christianity is extremely diverse in any case. Dobzhansky, for example, was a devout Russian Orthodox Christian, but he was by no means conventional in his beliefs.

Whether this perspective is a fit with traditional religion is debatable. My own feeling is that we can see this much, at least... it has been a traditional belief all down the centuries that all natural processes are established by God. This foundational belief has been maintained many many Christians even as our understanding of those processes has developed.

Don't Redefine Evolution

We don't have to agree with Dobzhansky. But it would be rash to say that his view was inconsistent with evolution, or that he redefined evolution! As one of the major developers of the "New Synthesis" of evolutionary biology with genetics in the 1960s, Dobzhansky has an excellent claim to being one of those who established the definitions of evolution that we use today!

D'Souza recognizes that taking an explicit anti-Darwin position makes you look like a yahoo. As far as I can tell he's recognizing Darwinian evolution as it is conventionally defined. I see no flagrant errors in the details of evolutionary biology involved; and no redefinition.

The explicitly anti-Darwin position of the modern Intelligent Design movement so popular with D'Souza's fellow religious conservatives is a position of breathtaking inanity, fostered by culpable ignorance and calculated dishonesty in its public defenders. The real risk from attempts to rebadge intelligent design is the problem of the big tent. The risk is that they'll say one thing to one audience and another for a different audience, and try slide anti-Darwinian design of specific forms into the arena under the cover of a vague belief in a creative design underlying the whole cosmos.

D'Souza is, as far as I can tell, recognizing the validity of evolution, but arguing that it's a part of the whole design. That's a position that can and should be argued. But let's not argue it by redefining evolution ourselves!

This has nothing to do with wanting atheists to keep silence, or with rolling over and accepting the validity of religion, or with avoiding offense to believers who happen to be allies in the fight against creationist pseudoscience.

Evolutionary biology makes no mention of plans, or designs, or Gods. We have no need of that hypothesis. The same is true of meteorology, geology, physics, chemistry or any other science. There is not even an additional clause to say "there's no God who set this up". To argue for or against God's existence can use arguments relating to empirical science, but they have to go further than this and into some metaphysics.

Distorting science to insert our own metaphysics is bad because it distorts science. It is bad when done by believers, and it is bad when done by unbelievers.

Read the full post...

Saturday, 5 May 2007

The Power of PZ

Duo Quartuncia is just a week old, but it got one hell of a kick off. The graph shown here is my hit count on Friday May 4, courtesy of sitemeter.

PZ Myers, of the Pharyngula blog, picked up my story on "Darwin is Dead" is Dead. He wrote just four lines (at "But Darwin is still dead anyway") and linked back to me for the details. Pharyngula must be the most popular science related blog on the net, and as a result of this post, my hit rate suddenly went through the roof. The graph tells the story.

I was up late that night, just to see where all my visitors were coming from. I have had visits from Chile, Uruguay, Brazil, South Africa, Phillipines, Singapore, Malaysia, Thailand, South Korea, Japan, Saipan, India, Iceland, Norway, Sweden, Finland, Denmark, Poland, Netherlands, Belgium, England, Ireland, Scotland, Spain, Portugal, France, Austria, Germany, Switzerland, Italy, Bratislava, Latvia, Turkey, Canada, USA, Dominican Republic, Australia, and New Zealand. Thanks everyone.

This blog is still very new. I am at presenting considering ways to improve the presentation and design. If anyone has suggestion, or just wants to say hello, please do so. I will be very grateful for any suggestions!
Read the full post...

Friday, 4 May 2007

The Evolution of Wings

Image of Archaeopteryx and Microraptor by Jennifer (Jenna) Bolen, UC Santa Cruz.

This is a sequel to my earlier blog entry on an exhibition of Chinese dinosaurs, with a PhD student in attendance giving visitors some free lessons in paleontology and dinosaur evolution.

The thing I found most interesting was his discussion of the probable evolutionary development of wings.

Background: what use is half a wing?

It's a common argument from anti-evolutionists that evolution of specialized structures like a wing is impossible, because the initial stages would serve no useful function and so could not possibly be selected. As creationists sometimes ask: "What use is half a wing?". This is number CB921.2 in the Index to Creationist Claims.

The index provides answers -- there are many things that a "half wing" could be good for.

The question incorporates a misconception. Individual organs don't evolve in isolation. They are part of a complete living organism, and the whole organism evolves together. At any point along a successful lineage, you are bound to have effective fully functional organisms, well adapted to their particular lifestyle. There may be positive selective pressures giving some direction to the changes that accumulate along the lineage, but successful variants are those that incorporate changes with an immediate benefit. Just grafting a wing that is complete for an eagle onto a Velociraptor dinosaur would not work; because the rest of the Velociraptor's body is adapted for a different lifestyle to that of the soaring eagle. If a particular organism has "half a wing", than that is most likely pretty much the right kind of wing for that organism.

Another consideration is functional shift. The ancestral forms of any organ may have been adapted for quite different purposes, and over time their primary function shifts from one role to another. If you could replace "half a wing" with a "full wing", then you may actually make matters worse, since the change removed some other other important function that is vital to the ancestral form.

A common argument from the evolutionist side, in attempting to fill out an entire hypothetical picture of evolution, is that even the tiniest fraction of a wing might give at least SOME benefit, perhaps in breaking a fall, and so this is leverage for evolution. This response runs the risk of contributing to the misunderstanding of thinking that the original form is properly understood as a half-wing.

Natural selection is, for the most part, a conservative force, acting to weed out damaging mutations and to retain existing function. You can have positive selection for a gradual change, but this really only works if there is also a strong selection against losing change in the reverse direction.

Functional shift

The relevance of this to wings is that if an organism has some proto-wing which has only the tiniest contribution as a wing, then this is not likely to be a sufficient explanation for how a wing can evolve. You might think that even 1% of a wing still gives some leverage to evolution. Actually, it quite probably does not.

This point is well argued in the context of insects by Kingsolver and Koehl, Selective Factors in the Evolution of Insect Wings (Annu. Rev. Entomol. 1994.39:425-5). It was found that the tiny contribution of the earliest proto-wings to flight was not able to account for the kinds of selective pressures that could plausibly explain wings. The solution is found in functional shift: wings originally were selected for a different function – thermoregulation. In this case, the initial thermo-regulators could still give a substantial benefit to a well-adapted organism, despite being too small for aerodynamic qualities to be of much importance. This allowed leverage for evolution to drive to greater surface areas for more effective thermoregulation; and co-incidentally this was just the kind of change that gave them also the quality of aerodynamic function.

Furthermore: at small sizes, an increase in size of wings had a significant effect on thermoregulation but little effect on aerodynamics. But as the wing size became larger, further increases in size had little further impact on thermoregulation but a substantial impact on aerodynamics. This is illustrated in the following figure.

"The thermoregulatory (upper curve) and aerodynamic (lower curve) Advantages for increasing wing length in insects. Note that thermodynamic benefits accrue rapidly when the wing is very small (too small for flight), but scarcely increase at all for wings of larger size. Aerodynamic advantages, on the other hand, are insignificant for small size, but increase rapidly at larger wing dimensions, just as the thermodynamic benefits cease."

(Reproduced from Not Necessarily a Wing, by Stephen Jay Gould.)

Back to dinosaurs: Sinornithosaurys millenii

One of the fossils recently found in China is Sinornithosaurus milleni. Sinornithosaurus is a dromaeosaur, part of a family of agile meat eating dinosaurs. Another famous dromaeosaur is the Velociraptor, which had a starring role in Jurassic Park. In fact the models in the movie were based on Deinonychus; and since then we have learned that these animals had feathers. A fossil Deinonychus is illustrated below, and an artist's impression for Sinornithosaurus graced my earlier blog article on the subject.

Sinornithosaurus was not a bird, and it could not fly. Its forearms are not wings; but the fossil shows two crucial "preadaptions" for bird wings. Sinornithosaurus has feathers, or proto-feathers. It seems probable that these structures developed mainly for insulation. The feathers were not adapted for flight, but would have been more like a kind of soft coat of down. Such a coat can help trap a layer of air next to the skin. We can't prove definitively the various stages, but it is plain that selection for a capacity to give insulation will lead to structures that trap air, and this in turn gives an increased capacity to push on air, or develop an aerodynamic effect.

The other significant preadaption are the long forearms, and their range of movement. Many dinosaurs had very small forearms; Tyrannosaurus Rex being a classic example. Such forearms could not possibly give rise to wings, and small changes in a stunted forearm will have no selective advantage for wings.

However, there may be selective advantage for a longer forearm in dinosaurs that use their arm for an attack. Sinornithosaurus had very long arms, and furthermore they had an extended range of movement. This was a matter of special interest to the PhD student at the Chinese Dinosaurs exhibition. The skeleton indicates that this dinosaur was able to move its arms above the head, and would have been able to bring them down for a slashing attack on their prey. This movement needs to be in place before there can be selection for wings; but the selection force for developing this movement is a capacity to attack. They had long legs, and were probably well suited to run down and leap on their victims.

Dinosaur dreaming

Fossils of Buitreraptor (foreground) and Deinonychus (background) at the Field Museum of Natural History in Chicago, Illinois. Photo by C. Horwitz, available at wikipedia.

We don't know all the stages in the ancestry of birds, but the transitional fossils we see indicate how the initial dinosaur form merges into that of birds. Sinornithosaurus, and many other fossils from the Yixian formations in Northern China and elsewhere, give an insight into now extinct forms of life. It's not possible to prove how selection worked on these creatures; but that they were as subject to selection as any other living thing is plain.

The relationships between these dinosaurs and birds have been emerging as we continue to find fossils of bird-like dinosaurs, and dinosaur-like birds; all fully functional living organisms in their own right, but with a mix of characters that make them splendid examples of "transitional" fossils. Precisely how the various processes of evolution worked out, and the full details of lineage, will never be given as a complete finished picture.

The glimpses we have do show the kinds of forms that gave rise to modern birds, and they show ample scope for selection to apply by small changes in form as an arm becomes longer, and with a wider range of movement, and with a coat of feathers, and with a benefit to a sudden spurt of speed to jump and leap out at prey. It may not have been exactly like that; and maybe other processes and effects will be found; and quite possibly there are significant contributory factors that will never be revealed.

Imagination and speculation are important qualities for a scientist. These ancient forms are thrilling and fire the imagination all the more for being based in reality. Children love dinosaurs, and the best scientists (IMO) continue to be driven by a child-like wonder at the ancient world they explore, combining an active imagination with detailed and rigourous study of all evidence available.

Update. This post is part of the Tangled Bank blog carnival #79. Check out all the other posts available.

Read the full post...