Obama supports science over ID

It was very refreshing (and reassuring) to read this reply that Barack Obama made in an interview with the York Daily Record:

Q: York County was recently in the news for a lawsuit involving the teaching of intelligent design. What’s your attitude regarding the teaching of evolution in public schools?

A: “I’m a Christian, and I believe in parents being able to provide children with religious instruction without interference from the state.

But I also believe our schools are there to teach worldly knowledge and science. I believe in evolution, and I believe there’s a difference between science and faith. That doesn’t make faith any less important than science.

It just means they’re two different things. And I think it’s a mistake to try to cloud the teaching of science with theories that frankly don’t hold up to scientific inquiry.”

There are two important points here that, hopefully, reflect the way that Obama really feels about this issue.  He says that religion and science are two different things; in essence, Gould’s non-overlapping magisteria.  Given the level of religious language he is prone to use (I’m a Christian; while obviously he has to stress it to overcome the accusations that he is Muslim, by using that word proudly it separates him from many liberal Christians who find themselves uncomfortable using that term because of what it means to people who are accustomed to hearing it coming from fundamentalists and right-wing evangelicals), it’s reassuring to see him come out as pro-evolution.

The most important bit though was the last line – I think it’s a mistake to try to cloud the teaching of science with theories that frankly don’t hold up to scientific inquiry.  There’s something about that phrasing which says “he’s on our side”.  Whether that’s true or not is beside the point – what’s reassuring is that he (or more likely, someone on his staff) bothered to figure out beforehand what the whole Kitzmiller trial was about, and chose to communicate in the language of one side.  This doesn’t sound like the language of the average politician – this is the language of someone who has heard the pro-science arguments.

H/T John Pieret.

Virtual Law?

While I am fairly familiar with some types of online communities, there has always been a vast world into which I have never delved – the world of MUDs, the best known of which are probably World of Warcraft and Second Life.  I can’t say I’m surprised by the idea of virtual law, but I really hadn’t given the idea much thought.

Anyway, Benjamin Duranske has publisheda book on virtual law; Taran got a pre-publication copy, and gives it a a glowing review:

 Virtual Law: Navigating the Legal Landscape of Virtual Worlds scored a KnowProSE.com 10 out of 10, a score I am loathe to give out to anyone. The book is timely, circumspect, well written and grounded where it is supposed to be while provocative in areas that it needs to be.

Tangled bank

I will be hosting the April 2^nd edition of the Tangled Bank. What’s that, you ask? It’s a blog carnival dedicated to posting on the subject of biology, medicine, or natural history, defined very broadly, and it’s sufficient that you show some passion for the science of the natural world. So pick your best post for the last two weeks and get your submission ino to host@tangledbank.net with the words “Tangled Bank” somewhere in the subject line. Or you can just drop me a link in the comments here.

Stein blames wrong scientists?

Obviously Expelled is a propaganda piece adding pseudohistory to the pseudoscience of intelligent design. But as Orac points out, if Stein actually wanted to slur scientists for inspiring the Holocaust, there’s a far strong case to attack Pasteur and Koch for inspiring Hitler.

In fact, it has been seriously argued that the Holocaust was based on not evolution, but concepts of immunology…

Hitler never explicitly likened himself to Charles Darwin. At least, if he did there is no record of it. Indeed, I challenge Ben Stein to show me an example where Hitler ever likened himself to Darwin. But he did explicitily liken himself to Robert Koch! (That evil atheistic baby-killer! Who knew?) In fact, Hitler even went one step further:

At Hitler’s table talk on 22 February 1942, the following statement was recorded:

It is one of the greatest revolutions there has ever been in the world. The Jew will be identified! The same fight that Pasteur and Koch had to fight must be led by us today. Innumerable sicknesses have their origin in one bacillus: the Jew! Japan would also have got them if it had remained open any longer to the Jew. We will get well when we eliminate the Jew.

If the Expellers actually believed that the science that inspired Hitler was to blame for the Holocaust, they should be attacking Koch and Pasteur. But that wouldn’t work – Pasteur’s name is on your milk. And immunology – well, far fewer people take issue with the germ theory of disease (even though, of course, it directly contradicts the Gospel accounts of Jesus’ ministry). Evolution, which clashes with a couple lines at the start of Genesis, is “the enemy”. I suppose it’s harder to demonise something that’s that obviously important to your everyday life.

Hitler was a YEC?

From J-Dog at Antievolution.org

BUT – There is a passage in your re-print that is worth pointing out that seems to be direct evidence that HITLER  WAS A YEC!!

“… and once again this planet, empty of mankind, will move through the ether as it did thousands of years ago ” – (my emphasis)

His comment is inspired by: Ben Stein re-writes Mein Kampf

Genetic legacies of human invasions

Really interesting stuff: according to the BBC, a paper published in the American Journal of Human Genetics reports that a faint genetic legacy of the Crusades appears in Lebanon, mostly among Lebanese Christians. And while Lebanese Christians and Muslims are overwhelmingly of the same stock genetically, Lebanese Muslim populations showed a genetic signature originating in the Arabian peninsula.

Update: The original paper is even more interesting than the BBC summary suggests. They looked at Y-chromosome diversity in four areas of the country – Mount Lebanon, the Bekaa, north Lebanon and south Lebanon, excluding Beirut because its population reflects recent migration from all over the country and classified people as Muslim (Shiite or Sunni), Christian or Druze.

Even in as small a country as Lebanon, they found that there was significant genetic differences between regions of the country. But there was about three times as much difference between religious groups as there was between regions.

Apparently it’s rare to find genetic differences between religious groups within a country, but for Lebanon the Arab invasion introduced Arab Y-chromosomes to what became the Lebanese Muslim population, but not the Lebanese Christians. Similarly, the Crusades introduced European Y-chromosome lineages to the Lebanese Christian population. They failed to find any genetic signature associated with the Ottoman conquest of Lebanon.

I have wondered in the past if the Crusaders left descendants in the Middle East. Most popular histories of the Crusades end with their cities falling, one by one, and the massacres that followed the fall of each city. But sometimes you come across an account that talks about peaceful surrenders. Still, the much larger crusader armies are likely to have left as large an imprint as the far smaller groups who stayed behind and tried to hold the conquests.

1. Zalloua et al., Y-Chromosomal Diversity in Lebanon Is Structured by Recent Historical Events, The American Journal of Human Genetics (2008), doi:10.1016/j.ajhg.2008.01.020 (If that link isn’t working, try this one).

Noah’s Ark

The story of Noah’s Ark is one of the more disturbing of the well known stories in the Bible.  The idea of a deity that would wipe out all but eight humans in order to knock back (but not eliminate) evil in the world… It’s a disturbing story on so many levels.  James McGrath takes a look at the question “can Noah’s Ark be Savaged?”  He says

The best way to make sense of the story is to show how it, like all the Biblical literature, reflects the development of human thinking about God that has led us to where we are today, rather than as static proclamations of things one ought to believe about God.

People tend to focus on the “good” part of the story – the promise not to do it again, the covenant with Noah.  But that requires you to set aside the depiction of God as an abusive parent, an Andrea Yates, as James suggests.

(You should also read his previous post “God’s Wife“.)

Berry Go Round #3

The third edition of Berry Go Round is up at Greg Laden’s Blog.  Berry Go Round is a new, botanically-oriented blog carnival.  You can submit a blog post for the next issue here.

Disturbance and recovery in tropical dry forests

When people think about the destruction and degradation of tropical forests, they tend to focus on rainforests. Tropical dry forests tend to get overlooked. They aren’t as striking – no cathedral-like understorey, no mind-boggling biodiversity. But more importantly, they often just aren’t there. Over much of their potential range they have simply been erased from the landscape. They may have covered as much as 42% of the land area in the tropics¹, but have been reduced to less than 27% of their former range in Mexico², and as little as 2% in Central America³ and New Caledonia⁴.

Despite the fact this, tropical dry forests are often seen as being quite well-adapted to human disturbance. Being less species-rich than wetter forests, they tend to support fewer rare species, and may be less extinction-prone. In addition, dry forests are dominated by trees that sprout after being cut. This means that if you cut down a patch of dry forest, most of the stumps will re-sprout. This type of recovery is much quicker than you would get if the trees had to germinate from seeds – not only does it take much longer for seedlings to grow large (stump sprouts can draw on resources stored in the roots of the tree), but there’s likely to be a time lag as seeds disperse into the area from surviving trees (tropical forests tend to lack long-lived seedbanks).

Much of our understanding of succession in tropical dry forests comes from Jack Ewel’s dissertation work. Ewel looked at the effect of cutting and herbicide application on succession in a series of plots across the Neotropics. One of his important findings was the dry forests were quicker to recover their stature that wetter forests. Since most of the recovery comes from stump sprouts, the recovering forest is also close to the original forest in terms of species composition.

While lightly used dry forest sites recover rapidly, recovery is slower in more intensively used sites. Seedling survival rates are very low in dry forests – while seedlings establish in the wet season, most (often all) of them die in the subsequence dry season. So while intensively used sites in Guánica Forest recovered well in terms of structure, biomass and leaf fall in 50 years after abandonment, the recovery of species composition was very slow⁶.

Resilience is the rate of recovery of disturbed sites to their pre-disturbed state. Ewel’s work helped to establish the idea that dry forests are more resilient than wetter forests. But there is no single rate – or pathway – of recovery. Measures of “recovery” depend on the parameter measured – canopy height, biomass, species richness, nutrient cycling… It also depends on the baseline against which recovery is measured: if the same site is measured before and after disturbance, you need to know if the site represented “mature” forest before disturbance. If another site is used, you need to wonder if it is really representative of initial conditions in your experimental plot.

In a forthcoming paper⁷ in the journal Biotropica, Edwin Lebrija-Trejos and coauthors looked at what it really means to say that tropical dry forests are more resilient than wetter forests. They looked at a sequence of 15 sites in Oaxaca, Mexico, which had been cultivated and then abandoned for 0-40 years, and compared them with nearby mature forest. All of the sites had been cultivated for a short period (1-2 years) and then abandoned without being converted to pasture⁸. They considered a variety of different ways to measure resilience – they looked at forest height, plant density, basal area (the area occupied by tree stems), crown cover, species richness, species density (number of species per 100 m²), Shannon evenness and Shannon diversity. Not surprisingly, they found that certain features (canopy height, plant density, crown cover) recovered rapidly (in less than 20 years) while others (including basal area and species richness) had not recovered after 40 years.

When compared their sites with other comparable studies, they found that their sites were among the quickest to recover canopy cover and height. On the other hand, they found that their sites were among the slowest to recover species diversity and average in terms of the recovery of species richness. Overall, in terms of the structural measures that Ewel focussed on, it’s reasonable to conclude that dry forests are more resilient that wetter forests. On the other hand, with regards to things like basal area and species richness, the assertion of resilience for dry forests isn’t well supported.

1. Brown, S., and A. E. Lugo. 1982. The storage and production of organic matter in tropical forests and their role in the global carbon cycle. Biotropica 14:161-187.
2. Trejo, I., and R. Dirzo. 2002. Floristic diversity of Mexican seasonally dry tropical forests. Biodiversity and Conservation 11:2063–2084
3. Janzen, D. H. 1988. Tropical dry forests: The most endangered major ecosystem. In E. O. Wilson (Ed.). Biodiversity, pp. 130–137. National Academy Press, Washington, DC
4. Gillespie, T. W., and T. Jaffré. 2003. Tropical dry forests in New Caledonia. Biodiversity and Conservation 12:1687–1697.
5. Ewel, J. J. 1971. Experiments in arresting succession with cutting and herbicide in five tropical environments. Ph.D. University of North Carolina, Chapel Hill.
6. Molina Colón, S., and A. E. Lugo. 2006. Recovery of a subtropical dry forest after abandonment of different land uses. Biotropica 38:354–364.
   
7. Lebrija-Trejos, E., Bongers, F., Pérez-García, E.A., Meave, J.A. (2008). Successional Change and Resilience of a Very Dry Tropical Deciduous Forest Following Shifting Agriculture. Biotropica DOI: 10.1111/j.1744-7429.2008.00398.x
8. Conversion to pasture tends to slow recovery significantly; not only does the prolonged period eliminate almost all root stocks, it also establishes a grassy layer that makes it more difficult for tree seedlings to establish.

Dawkins and Myers discuss the Expelled fiasco

Apparently they use the Harvard XVIVO film is used with a creationist commentary.  Is it the same Big Gay Al narration that Dembski used?

There’s a version at RichardDawkins.net.  Dawkins calls it “a spectacular own goal” and describes it as shoddy film making.

H/T Scott Hatfield.