Tag Archives: Simulation

Is it better to form beliefs based on evidence or based on consensus?

Stuart Schneiderman linked to this Wall Street Journal by Matt Ridley.

Take a look at this:

Last week a friend chided me for not agreeing with the scientific consensus that climate change is likely to be dangerous. I responded that, according to polls, the “consensus” about climate change only extends to the propositions that it has been happening and is partly man-made, both of which I readily agree with. Forecasts show huge uncertainty.

Besides, science does not respect consensus. There was once widespread agreement about phlogiston (a nonexistent element said to be a crucial part of combustion), eugenics, the impossibility of continental drift, the idea that genes were made of protein (not DNA) and stomach ulcers were caused by stress, and so forth—all of which proved false. Science, Richard Feyman once said, is “the belief in the ignorance of experts.”

My friend objected that I seemed to follow the herd on matters like the reality of evolution and the safety of genetically modified crops, so why not on climate change? Ah, said I, but I don’t. I agree with the majority view on evolution, not because it is a majority view but because I have looked at evidence. It’s the data that convince me, not the existence of a consensus.

My friend said that I could not possibly have had time to check all the evidence for and against evolution, so I must be taking others’ words for it. No, I said, I take on trust others’ word that their facts are correct, but I judge their interpretations myself, with no thought as to how popular they are. (Much as I admire Charles Darwin, I get fidgety when his fans start implying he is infallible. If I want infallibility, I will join the Catholic Church.)

And that is where the problem lies with climate change. A decade ago, I was persuaded by two pieces of data to drop my skepticism and accept that dangerous climate change was likely. The first, based on the Vostok ice core, was a graph showing carbon dioxide and temperature varying in lock step over the last half million years. The second, the famous “hockey stick” graph, showed recent temperatures shooting up faster and higher than at any time in the past millennium.

Within a few years, however, I discovered that the first of these graphs told the opposite story from what I had inferred. In the ice cores, it is now clear that temperature drives changes in the level of carbon dioxide, not vice versa.

As for the “hockey stick” graph, it was effectively critiqued by Steven McIntyre, a Canadian businessman with a mathematical interest in climatology. He showed that the graph depended heavily on unreliable data, especially samples of tree rings from bristlecone pine trees, the growth patterns of which were often not responding to temperature at all. It also depended on a type of statistical filter that overweighted any samples showing sharp rises in the 20th century.

I followed the story after that and was not persuaded by those defending the various hockey-stick graphs. They brought in a lake-sediment sample from Finland, which had to be turned upside down to show a temperature spike in the 20th century; they added a sample of larch trees from Siberia that turned out to be affected by one tree that had grown faster in recent decades, perhaps because its neighbor had died. Just last week, the Siberian larch data were finally corrected by the University of East Anglia to remove all signs of hockey-stick upticks, quietly conceding that Mr. McIntyre was right about that, too.

So, yes, it is the evidence that persuades me whether a theory is right or wrong, and no, I could not care less what the “consensus” says.

I think that one of the most troubling things about college students today is that they are so much under the influence of their professors that they regularly just parrot whatever their professors say in order to pass their classes. They can’t afford to ask questions and disagree – they’ve already paid their money, and their job is to agree with the professors in order to pass. This is especially true with secular leftist professors who are often woefully incapable of respecting views other than their own. The ivory tower is not the best place for having one’s views tested by reality, as Thomas Sowell has argued. This is especially true outside of the fields of engineering, math, science and technology. So, young people tend to come out of university parroting the view of their professors, who often don’t know how the real world works at all. The right thing to do to fix this problem is for universities to promote a diversity of views. But that’s not likely to happen in universities that are dominated by progressives. Non-progressive views are not just wrong, but evil. Rather than be viewed as evil by professors and peers for the crime of thinking critically, most students prefer to stick with the consensus views, whether they are defensible or not.

New paper casts doubt on Stuart Kauffman’s self-organization theory

One of the naturalistic theories for the origin of biological information in the origin of life is Stuart Kauffman’s “self-organization” theory. The theory attempts to account for the functional sequences of information in living systems by arguing that the information emerges automatically from a sufficiently diverse pre-biotic soup.

In his book, “At Home in the Universe”, Kauffman writes:

I hope to persuade you that life is a natural property of complex chemical systems, that when the number of different kinds of molecules in a chemical soup passes a certain threshold, a self-sustaining network of reactions—an autocatalytic metabolism—will suddenly appear. Life emerged, I suggest, not simple, but complex and whole, and has remained complex and whole ever since… The secret of life, the wellspring of reproduction, is not to be found in the beauty of Watson-Crick pairing, but in the achievement of catalytic closure.

Doug Axe explains the theory a bit more: (H/T Evolution News)

When chemicals react, they produce different chemicals. So the idea here—call it Kauffman’s conjecture—was that mixtures with a sufficient number of different chemicals are bound to give rise to local compositions that continually replenish themselves through a self-catalyzed network of chemical reactions.  Those special compositions would typically differ from the original mixture, but since they make more of themselves, they should be able to ‘grow’ by establishing themselves repeatedly in local pockets.  The ability to propagate in this way, if proven, would be something like reproduction, only at the low level of chemical composition rather than at the high level of organismal form.

It was clear enough to me why Kauffman and others liked this idea.  If some kind of reproduction and inheritance could conceivably be achieved in systems that are much, much simpler than anything we think of as living, then maybe scientists were making the problem of explaining life much, much harder than it really needed to be.

But now a new peer-reviewed research paper has cast doubt on this naturalistic theory.

Axe explains:

The paper’s title is a diplomatic statement of its main conclusion: Lack of evolvability in self-sustaining autocatalytic networks constrains metabolism-first scenarios for the origin of life.  It becomes clear on reading the paper that the word constrains is here being used euphemistically. After testing the effect of fitness on the evolution of their model compositional assemblies, they report that “some slight relative increases and decreases in their replication-mutation equilibrium frequencies are detected, but the effects are so minor that it is hard to think of any evolutionary relevance.”  The problem is that the behavior of the whole system is almost completely determined by the inherent chemistry, leaving no room for selection to do anything interesting.

The citation is “Lack of evolvability in self-sustaining autocatalytic networks constraints metabolism-first scenarios for the origin of life”, Proceedings of the National Academy of Sciences USA, vol. 107, no. 4, pp. 1470-1475.