Author Michael Shermer offers us a pithy definition of natural selection: “Natural selection simply means that those individuals with variations better suited to their environment leave behind more offspring than individuals that are less well adapted.” Michael Shermer, Darwin Misunderstood, Scientific American, Feb. 2009, at 34 (emphasis added).
Related post:
It’s possible that our universe wasn’t specifically designed to support life as we know it, but is merely one of many possible universes, and ours happens to ‘work.’ This, according to some atheists, is supposedly a rebuttal to the claim of scientist-theologians that the fine-tuning of our universe suggests the hand of a Designer.
(The atheists generally brush under the rug the question posed by the Rev. Dr. John Polkinghorne: If in fact there are multiple universes, that’s all well and good, but then where did they come from?)
Hacker News points us to Dark flow: Proof of another universe? by Amanda Gefter, New Scientist, Jan. 22, 2009. Here’s an excerpt:
Kashlinsky, a senior staff scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, …. and colleagues have clocked galaxy clusters racing at up to 1000 kilometres per second – far faster than our best understanding of cosmology allows. Stranger still, every cluster seems to be rushing toward a small patch of sky between the constellations of Centaurus and Vela.
Kashlinsky and his team claim that their observation represents the first clues to what lies beyond the cosmic horizon. Finding out could tell us how the universe looked immediately after the big bang or if our universe is one of many. Others aren’t so sure. One rival interpretation is that it is nothing to do with alien universes but the result of a flaw in one of the cornerstones of cosmology, the idea that the universe should look the same in all directions. That is, if the observations withstand close scrutiny.
(Emphasis added.)
Related posts:
Today's WSJ (Europe) contains a thought-provoking piece by Gunnar Heinsohn about the ongoing 'youth bulge' in Gaza, fed by a six-babies-per-woman average birth rate that is subsidized by the West. We can conjecture that this results in at least a modest selection bias in favor of aggressive males, who — assuming they survive to sire children — seem likely to sire more children on the whole than passive or timid ones. (This is a questionable assumption, of course; some women may have a stronger preference for men who are likely to be around to help raise the kids than for those who are likely to get themselves killed.)
Excerpt:
In such "youth bulge" countries, young men tend to
eliminate each other or get killed in aggressive wars until a balance
is reached between their ambitions and the number of acceptable
positions available in their society.The reason for Gaza's endless youth bulge is that a large majority of its population does not have to provide for its offspring. Most babies are fed, clothed, vaccinated and educated by UNRWA, the United Nations Relief and Works Agency for Palestine Refugees in the Near East. … [@para;]
The Hamas-Fatah truce of June 2007 allowed the Islamists again to direct all their energy on attacking Israel. The West pays for food, schools, medicine and housing, while Muslim nations help out with the military hardware. Unrestrained by such necessities as having to earn a living, the young have plenty of time on their hands for digging tunnels, smuggling, assembling missiles and firing 4,500 of them at Israel since 2006. … [¶]
… By generously supporting UNRWA's budget, the West assists a rate of population increase that is 10 times higher than in their own countries. Much is being said about Iran waging a proxy war against Israel by supporting Hezbollah and Hamas. One may argue that by fueling Gaza's untenable population explosion, the West unintentionally finances a war by proxy against the Jews of Israel.
If we seriously want to avoid another generation of war in Gaza, we must have the courage to tell the Gazans that they will have to start looking after their children themselves, without UNRWA's help. This would force Palestinians to focus on building an economy instead of freeing them up to wage war. Of course, every baby lured into the world by our money up to now would still have our assistance.
(Bold-faced emphasis added.)
Heinsohn's diagnosis seems very plausible, but his prescription is more than a bit lacking. He does not explain how exactly we are suppose to induce Gazans to reduce their birth rate, while simultaneously continuing to provide assistance for "every baby lured into the world by our money up to now[.]" (Tom Evslin has a couple of observations on that score.)
Related post:
Yesterday's news prominently featured an Israeli air strike in Gaza that killed leading Hamas militant Nizar Rayan, all four of his wives, and 9 or 10 of his 12 children. I wonder if the Muslim approval of polygyny, allowing men to have up to four wives if necessary for humanitarian reasons, may help explain why Islamic militants seem to be some of the most aggressive on the planet. I would think that, other things being equal:
• The men most prone to seek multiple wives would tend to be the assertive and even aggressive ones. (This premise intuitively makes sense, but that's all the more reason to give it careful scrutiny before making any significant bets on my reasoning here.)
• Every time a polygynist takes an additional wife, his action has a double-whammy effect on the makeup of the next generation's population: It reduces the number of women available to bear the children of more-passive men, and it increases the number of women who will bear the children of assertive ones.
• Thus, in a society that allowed multiple wives, over time we would expect more descendants of assertive men, and fewer descendants of passive ones, than we would expect in a monogamous culture.
Assuming intuitively that assertiveness is at least partially determined by heredity (another assumption requiring critical scrutiny), this gives us a clue about how a society might eventually look after X generations of polygyny.
The above analysis is pretty simplistic, of course. It doesn't take
into account other factors that doubtless contribute to the hyper-aggressiveness of Islamic militants, such as overcrowding in Palestinian 'refugee camps' and the inability of
many Islamic societies to generate the kind of widespread economic progress that is comparatively common
in the West. (The latter may itself be due in part to a population prone to aggressiveness.) Nor does it take into account the increased likelihood that aggressive males might die violently before fathering as many children as they might have in a normal lifespan.
But I do suspect it there may be something to it.
From Why Israel Feels Threatened, by Benny Morris, NY Times, Dec. 29, 2008:
… The birth rates for Israeli Arabs are among the highest in the world, with 4 or 5 children per family (as opposed to the 2 or 3 children per family among Israeli Jews).
If present trends persist, Arabs could constitute the majority of Israel’s citizens by 2040 or 2050. …
Friction between Israeli Arabs and Jews is already a cogent political factor. In 2000, at the start of the second intifada, thousands of Arab youngsters, in sympathy with their brethren in the territories, rioted along Israel’s major highways and in Israel’s ethnically mixed cities.
… Down the road, Israel’s Jews fear more violence and terrorism by Israeli Arabs. Most Jews see the Arab minority as a potential fifth column.
In honor of the upcoming bicentennial of the birth of Charles Darwin, the January issue of Scientific American has evolution as its theme. One of my favorites is Testing Natural Selection, by H. Allen Orr, which has a nice explanation of how evolution works:
… the idea of natural selection is simplicity itself. Some kinds of organisms survive better in certain conditions than others do; such organisms leave more progeny and so become more common with time. The environment thus “selects” those organisms best adapted to present conditions. If environmental conditions change, organisms that happen to possess the most adaptive characteristics for those new conditions will come to predominate. Darwinism was revolutionary not because it made arcane claims about biology but because it suggested that nature’s underlying logic might be surprisingly simple.
There’s also a useful diagram at the top of pages 46-47.
I’m going to take my own stab at explaining the basics of evolution with an overly-simplified analogy, inspired in part by the diagram in the Orr piece.
Imagine you have a giant, slowly-spinning barrel labeled “Life.” The barrel contains two types of ‘organism’: Cubes and balls. Each cube and each ball contains a miniature factory for making more of its kind. (That’s ‘reproduction.’)
The Life barrel contains a bunch of square- and circular holes of different sizes. As the barrel spins, some of the cubes fall through some of the square holes and out of the Life barrel; some of the balls fall through some of the circular holes. (These holes represent death, a crucial player in evolution.)
Think about how differences in ‘birth rate’ and ‘death rate’ will change the proportions of cubes and balls over time:
Suppose that, on average, the cubes balls are able to ‘give birth’ to a few more of their own kind per day than are the balls cubes. Other things being equal, the barrel will contain increasingly-more balls than it does cubes as time goes on, because of this difference in ‘birth rates.’
But suppose that balls also ‘die’ faster, because there are many more circular holes in the Life barrel than square holes; thus, far more balls fall out of the barrel than do cubes. Suppose that this higher ‘death rate’ for the balls more than offsets their higher ‘birth rate.’ Other things being equal, over time the cubes, not the balls, will come to dominate the barrel’s population.
On balance, when a given cube eventually does die — and they all do — the odds are that it will leave more of its progeny in the barrel than will a given cube. Overall, the cubes are better adapted to life in the barrel than the balls.
But life in the barrel can change. Suppose that a freak lightning bolt burns another square hole into the barrel, and that mud clogs up some of the round holes. This increases the ‘death rate’ of the cubes and decreases that of the balls.
Now, the cubes no longer have quite the same evolutionary advantage over balls as they did before. Over time, we can expect to see the proportion of balls increase relative to the cubes.
The relative proportions of balls and cubes can change in other ways, too. For example, a cube could ‘mistakenly’ manufacture a ‘child’ cube that’s too big to fit through the smaller square-shaped holes. (That’s mutation.) The oversized child cube is likely to survive in the barrel longer than other cubes, meaning that it’s likely to leave more progeny behind than they do.
And if the oversized cube’s progeny are also oversized, what will we expect to see eventually? Over time, the relative proportion of normal-sized cubes will drop, because they ‘die’ at a faster rate than do the oversized ones.
* * *
That, in a nutshell, is evolution.
Yesterday’s Gospel reading was the Parable of the Talents in Matthew 25. Some observations:
• The two successful servants evidently trusted their master; they didn’t seem to share their third colleague’s ‘knowledge’ that the master was supposedly a harsh kleptocrat who reaped where he had not sown. Maybe the third servant had a warped view of things that caused him to fearfully hoard what he had instead of putting it to good use.
• I wonder if the manuscript of Matthew was badly edited: Maybe those who will be given more aren’t those who have, in the abstract, but those who specifically have trust in God, as the two successful servants had trust in their master. Likewise, for those who have nothing by way of trust in God, even what they do have in this world will inexorably be taken from them (as it will be from all of us): by rust and moths (Matt. 6.19) and other agents of chaos, aka the Second Law of Thermodynamics.
• Our senior associate rector, Doug Richnow, preached on how awesome a God must be who created the billions and billions of stars, planets, and us. He drew on Psalm 90 that’s also in the day’s readings, and on the evident fine-tuning of the universe‘s physical constants. (No, he didn’t argue against evolution.) Doug’s sermon got me to thinking: Taken together, Psalm 90 and the Parable of the Talents could be read as urging us to make the best use we can of whatever assets have been entrusted to each of us — not just because it pleases God in some vague and undefined way, but more specifically because that’s how we do our jobs as created co-creators, laboring in the service of the continuing creation. (I’m going to ask our music directors whether it was a coincidence that the closing hymn was Come, Labor On ….)
“Our universe is perfectly tailored for life. That may be the work of God or the result of our universe being one of many.” (Emphasis mine.) So says the slug of a very readable article by Tim Folger published yesterday in the on-line version of Discover magazine: Science’s Alternative to an Intelligent Creator: the Multiverse Theory.
The slug is wrong about one thing: It’s not an either-or proposition. Even if multiple universes have been created, and ours is the one we happen to live in, we’re still left with the question: How did that come to pass? (So says the Rev. Dr. John Polkinghorne, quoted in the Folger article, in one of his books.)
There’s no reason to think a Creator would not create multiple universes instead of just one. That would be roughly parallel with the way we think evolution works in our particular universe: Lots of ‘experiments,’ with the ones that work, continuing on.
Or as Paul says in 1 Thess. 5.20: Don’t scorn people who come up with novel ideas; instead, test everything, and keep that which seems good.
You’ve probably already seen the article from this past Saturday’s NY Times: A Teacher on the Front Line as Faith and Science Clash, by Amy Harmon.
David Campbell, the Florida biology teacher portrayed in the piece, deserves our gratitude for his persistence in defense of facing the facts. Equally laudable are his tact and his obvious concern for his students. The latter two qualities are clearly important in his efforts to wean the students off the creationist wishful thinking that they’ve been infected with by their parents and churches.
Pulitzer, perhaps?
At the decennial Lambeth Conference of Anglican bishops, traditionalist English bishop N.T. Wright (known as Tom) gave a lecture yesterday about the authority of Scripture. He reportedly spoke to a packed house. The lecture is worth reading in its entirety; it’s a wonderful blend of erudition and foolishness. (Hat tip: Thinking Anglicans.)
Bishop Wright urges us to read the Bible as though it were a five-act play. Hmm, an interesting concept. He says the play has "Creation and Fall as the first two acts, then Israel, then Jesus himself, and then the act in which we ourselves are still living, whose final scene we know from passages like Romans 8, 1 Corinthians 15 and Revelation 21 and 22."
In other words, according to Wright, the story of the universe revolves around a collection of tribes wandering the land bridge between northeast Africa and southwest Asia. The climactic event — the execution of one Jesus of Nazareth, and its aftermath — has already occurred. Since then, all the universe has been killing time waiting for the grand finale.
We’re familiar with this view of history, of course. For nearly 2,000 years, that’s been the narrative taught by the church.
The church fathers might have been excused for taking such a provincial view. In their day, humanity knew virtually nothing about the universe outside the earth’s atmosphere. We knew nothing at all about the origins of our planet, and of our species. (Correction: What we thought we knew was proved inadequate by later-revealed evidence.) Indeed, it’s not evident that the fathers, so focused on Israel and its putative history, were much aware even of other human cultures to be found in, say, China, India, and the Americas. The Jerusalem church fathers been taught that Israel was the Chosen People, and (all evidence to the contrary notwithstanding) that’s all they needed to know, except of course "Christ and Him crucified."
We of today can’t justify taking such a narrow, self-centered view of history. Unlike the church fathers, we know that on our planet alone, all kinds of diverse peoples each have their own history, and there’s no plausible reason to privilege any particular one of those histories as the essential narrative of the creation.
Let’s also consider that it might not be just our own planet that deserves our attention on this point. Astronomers are busily discovering planets orbiting other stars; it’s estimated that some 10% of sun-like stars may have planets. And we’re fairly confident that what we used to think of as "the Sun" is but one of hundreds of billions of stars in the Milky Way galaxy, and that our galaxy is but one of an estimated 125 billion galaxies. Our observations (for example, this week’s discovery of water on Mars) give us reason to think that the conditions for life may well exist on more than just our planet.
With all this in mind, you don’t have to be a cultural relativist to be unconvinced that the folk
tales of a single small people are truly the central narrative
of the universe. Bishop Wright seems content to assume that it is, however, and that nothing else we have learned about the history of the universe is of any real consequence. His Lambeth lecture reveals what Paul Zahl might call an extraordinarily-high anthropology; others might refer to it less charitably as cultural egotism.
For hundreds of years, humanity has been blessed with the steadily-increasing ability to observe the reality God wrought. We’ve likewise been blessed with inspirations about how those observations can be fitted together into coherent, testable models of the universe. Moreover, it seems eminently reasonable to conjecture that we are expected to put these gifts into the service of the continuing creation.
Yet the church insists on continuing to espouse an overly-simplistic narrative based on an exaggerated view of humanity’s importance in the cosmic scheme of things. At best, this is self-indulgence; at worst, a breach of the First Commandment.
Bishop Wright does come close to making an excellent point: He argues that:
… scripture offers precisely the unfinished narrative of God’s heaven-and-earth project,
God’s great design, as Paul puts it, echoing the Law and the Prophets,
to join everything in heaven and earth into one in Christ. And the
unfinished narrative functions like an unfinished play, in which those
who belong to Jesus Christ are now called to be the actors, taking
forward the drama towards its intended conclusion.
Within that unfinished play, he says, we human actors are supposed
to be improvisers, "which as any musician knows doesn’t mean playing
out of tune or out of time but rather discerning what is appropriate in
terms of the story so far and the story’s intended conclusion."