Faith vs Trust

August 24, 2011

Creationists – the loud ones, like Ken Ham, Kirk Cameron, and Kent Hovind – often repeat that evolution, like religion, is a matter of faith, and therefore evolution and religion-based beliefs on creation stand on equal ground. But this is a rhetorical ruse. In order to uncover the man behind this curtain, we need to look at “faith” vs “Faith”.

Faith with a capital F refers to religious faith – complete, unwavering acceptance of the tenets of a religion. But faith with a small f means something different. We can say we have faith in a pilot, and in the aircraft he is flying. What this means is not a complete, unwavering acceptance of the miracle of flight, but that we trust the pilot’s training, and the engineers’ skill. But that trust is not unwavering – evidence to the contrary (missteps by the pilot, or mechanical issues with the aircraft) will shake that trust. In the case of religious Faith, many are taught and believe that evidence contradictory to their religious beliefs is there to test their Faith, and so they entrench themselves further rather than changing their worldview.

In a sense, science is a matter of faith – but it is most definitely not a matter of Faith. I would rather say that science is a matter of trust. We trust that the laws of nature will not suddenly change. We trust that the tools we have at our disposal will give us reliable information. We trust that a preponderance of converging data is on the right track to representing how a phenomenon actually works.

But wait, there’s more…

Creationists will say that you have to have faith in Science just as you have to have Faith in religion – but you don’t. The reason Science is so reliable is that it works whether you believe in it or not! You can disbelieve in gravity, rocket propulsion (aka Newton’s 3rd Law), fluid dynamics, and evolution all you like. But that doesn’t make them not happen. So while most people do put some faith (trust) in Science, it is not required that they do so. And, in fact, a critical eye and healthy dose of skepticism (by which I mean real skepticism, not denialism) are necessary for Science to move forward – so scientists who trust the preponderance of existing knowledge do not automatically trust new discoveries.

So the next time you hear the argument that Science is just like religion, because it relies on faith, call that argument what it is: Bullshit.


Economic argument against the woo

October 20, 2010

XKCD for the WIN:


Quality, not quantity, leads to speciation

October 7, 2010

In 1859, Charles Darwin published a book that changed how biologists understand the living world. Although his book was titled “On the Origin of Species by Means of Natural Selection”, it never actually explained the process of speciation. Although an elegant and thorough explanation of the mechanisms underlying evolution, he extrapolates this to say “species have changed, and are still slowly changing by the preservation and accumulation of successive slight favorable variations”. In other words, natural selection produces change, and the accumulation of enough changes produces a new species. A century and a half later, this is still accepted wisdom.

For most Biologists (and scientists in general), accepted wisdom is not enough. Ernst Mayr put forth the notion of allopatric speciation – that physical isolation can allow genetic change to occur separately in two populations, eventually leading to reproductive isolation and thus to speciation. Steven Gould and Niles Eldridge produced the idea of punctuated equilibrium – that the history of life consists of long periods of stasis (ie species remain relatively unchanged) punctuated by rapid bursts of species diversification.

Although many viewed speciation and macroevolution as the rapid accumulation of many individual variations, effectively speeding up the process, others (Goldschmidt, Gould) proposed that these events occurred through single (or a small number of) events that produced significant morphological or physiological change. The technical term for this is saltation (meaning a jump), though Goldschmidt’s term “hopeful monster” is also used – not always kindly.

In the early 80’s, Homeobox genes were discovered. These are genes that regulate body pattern, and it was discovered that the duplication, relocation, and modification of these genes is responsible for significant changes in body plan. Suddenly there were genes that could produce “hopeful monsters” without significant genetic change. And yet, the gradualistic model of speciation through accumulation of many small changes has persisted, primarily because there has been no evidence that a single or small number of changes can produce enough change to create a new species.

Recently, Dr. Mark Pagel at the University of Reading decided to put to the test. He reasoned that if speciation is dependent on the accumulation of a number of genetic changes, that would show up statistically as a normal distribution in a survey of the number of genetic differences between species in the family trees of different groups.

What he found was that the distribution did not follow a normal curve, but an exponential (poisson) distribution instead. This is the distribution one finds with truly random distributions, such as the frequency of lightning strikes. The differences between these two random distributions are subtle but significant. The most important difference is that a normal distribution has a mode – a peak value around which the values are distributed. A poisson (exponential) distribution does not – any value is equally likely.

The implication for evolution is that there is no typical, usual, or expected number of mutations required for a population to become a separate species from its parent population. In other words, We can’t say that a new species arises after about 20 (or 60 or 2000) mutations. It may take any number of mutations to form a new species – 50, 100, 1000. Or just one.

At first this seems to fly in the face of the “accepted wisdom” that there is some sort of threshold for speciation. But given that mutation is random, any number of mutations could occur that produce little or no effect, or that do produce an effect but in genes that are unimportant. For speciation to occur, a change must arise that leads to a reproductive barrier. What this study tells us is that a sufficiently significant change is as likely to occur from a single mutation as from 10, 30, or 100.

So while the accepted wisdom – or at least the default assumption – is that speciation arises as the result of an accumulation of minor changes, it now looks more like a single significant change is responsible for a speciation event. The implication being that the quality of mutation, not quantity, is the deciding factor for speciation.

Although in retrospect this makes perfect sense, it does provide additional context for models of evolutionary change – such as punctuated equilibrium and Goldschmidt’s “hopeful monsters” – that were ridiculed when first proposed. Which just goes to show that Hamlet was right: There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.

http://www.nature.com/nature/journal/v463/n7279/full/nature08630.html

http://www.newscientist.com/article/mg20527511.400-accidental-origins-where-species-come-from.html?full=true


Gliese 581g – Define “Habitable”

October 1, 2010

Much has been made of the announcement about the recently announced discovery of a potentially habitable planet around a nearby sun. The planet, dubbed Gliese 581g is estimated to be around 3 times the Earth’s mass, and about 1.5 x it’s diameter (depending on composition).

The excitment over this particular exoplanet – the 492nd discovered – is that it lies in the “goldilocks zone” where th etemperature is not too hot, not too cold. That is, its distance from the star is such that the surface temperature is likely to be such that liquid water could exist on the surface, something that is key to life as we know it.

However, the announcements touting “Scientists discover habitable planet” and “Earthlike planet discovered around nearby star” are grossly misleading.

It is true that Gliese 581g lies in the goldilocks zone. However, we know nothing of its composition, its amosphere, or its rotation. This latter is important, as the planet lies only 0.15 AU’s from its parent star. In contrast, Mercury 0.39 AU’s from our sun. 581g’s proximity to the star means the planet is likely tidally locked – in other words, one side always faces the star, the other away. One side would be a permanent, hot day, the other a permanent, frozen night. Even with an atmosphere to carry heat back and forth between the two sides, much of the water and other atmospheric gases could freeze out on the night side, leaving a thinner atmosphere, and permanent desert on the day side. The temperature along the terminator (the “twilight zone”) should be intermediate, allowing for liquid water, but not if all the water is frozen on the night side.

On the other hand, the star Gliese 581 is a red dwarf star (which is why the goldilocks zone i sso close), which is very stable and long lived, so if there were conditions suitable to life, it would have a good ling time to evolve.

Until we have the tools available to analyze the spectrum of the atmosphere, we really can’t know any more, as much as we want to speculate.

This doesn’t mean we shouldn’t get excited – far from it. The discovery of Gliese 581g tells us something very important. It tells us that there are two earth(ish) size planets orbiting in the goldilocks zone in a tiny volume of space (relatively speaking) – Gliese 581g and our own. the statistical implication is that goldilocks planets are likely common in the galaxy. And that means that even if 581g is a lifeless, half-frozen wasteland, there are more earthlike planets out there.


The Triceratops that Never Wasn’t

August 11, 2010

 

I recently returned from a holiday abroad to find headlines proclaiming that Triceratops Never Existed! My first thought was of course, WTF? And my second thought was, just how stupid are they? And then the little pessimistic third thought was that the way this story is being waved about, it will be used as “ammunition” by antievolutionists, one more little item with which to further wrap themselves in ignorance.

So here is the story.

Ceratopsian dinosaurs were (mostly) large, quadrupedal herbivoves with a frill behind the skull, and many bore horns from the nose and/or the top of the skull over the eyes. There is substantial diversity in the group in the shape and size of the frill and horns, leading to the definition of many different genera and species. But there is also variation within each species, blurring the boundaries between the different classifications. Because of this, the group as a whole has undergone taxonomic revision several times. The recent work by John Scanella and Jack Horner continues this trend by further clarifying the taxonomy of this intriguing group.

Scanella and Horner surveyed known specimens of the ceratopsian classified as Torosaurus, and concluded that the developmental and morphological evidence suggests they are not members of a separate genus, but in fact “fully grown” members of Triceratops. This is bolstered by the fact that there are no known juvenile Torosaurus remains – though the discovery of such remains would, of course, reverse this change in classification. Since the name Triceratops was coined first, it remains while Torosaurus becomes obsolete (pending further study and corroboration by other researchers). This sort of thing happens all the time, partly because defining “species” for organisms that have been dead for 70 million years with only a limited dataset is tricky business, and partly because we learn more. Science progresses.

So, in fact, the story headlines should have read “Torosaurus reclassified as adult Triceratops“. But a) that requires understanding what is being written, and b) wouldn’t sell papers. It really ticks me off just how wrong the statement “Triceratops never existed” really is. Animals classified as Triceratops and Torosaurus did exist, which is why we have their fossils. The classification of one of these groups may be in error, but it would be Torosaurus that ceases to be as a genus.


On the Verge

March 30, 2010

We are now only hours away from the first attempted collisions in the LHC at an energy level of 7 TeV. This is the single largest scientific experiment in human history. The status can be followed online in real time:

http://op-webtools.web.cern.ch/op-webtools/vistar/vistars.php?usr=LHC1


UFOs and the Argument from Ignorance

March 29, 2010

This is a great video clip of Neil DeGrasse Tyson explaining the principle of argument from ignorance in the context of UFO sightings.


The Butterfly Effect

March 15, 2010

The “Butterfly Effect” is a term well known in popular culture, and I came across it again today. The problem is, what most people understand about it is completely wrong. Most people who know the term would describe it thusly:

A butterfly flapping its wings in China can cause a tornado in North America

Or some variation thereof. 

No.

The butterfly effect was introduced by Edward Lorenz, and popularized by James Gleick in his 1987 book Chaos: Making a New Science. Lorenz was a mathematician and meteorologist, and while modelling mathematical predictions of weather, he noticed that slight changes in initial conditions can lead to significant differences over the long term. The behaviour of the atmosphere is dependent on the state of adjascent atmosphere, which is in turn dependent on the state of its adjascent air masses, and so on. As each air mass changes, it alters its influence on all surrounding air masses. Slight changes thus can have slight influences which propagate throughout the atmosphere.

For long term weather prediction, the state of all variables must be known, as well as the exact influence of each variable on every other.  Given that the exact temperature, pressure, humidity, and velocity of each litre of atmosphere cannot possibly be known, real weather patterns will, over time, deviate from the prediction.  And even if we could know the exact state of every litre of atmosphere, there are other influences, including the motion of living things (butterflies, birds, people), and uneven surfaces which introduce turbulence. The more time passes, the more deviation will accumulate, leading to ever more rapid deviation.

So a butterfly will not cause a tornado, in the sense that the wing beat becomes amplified over distance. But to predict the existance and exact path of a tornado, weaks or months in advance, we would need to know every possible variable – and the simple beat of a butterfly’s wing would change the initial state, and thus change the outcome.  

Chaos theory is a fascinating field, and a very powerful tool. It lets us recognize that even if we understand exactly how a process works, we cannot predict the exact outcome of a process consisting of multiple, mutually influential variables. But conversely, not being able to predict exact outcomes doesn’t mean we don’t understand the process.


On East Anglia CRU’s hacked files

November 24, 2009

One scientific issue that may polarize people even more than evolution is anthropogenic global warming – the idea that CO2 from human activity is throwing off the natural balance, leading to significant, possibly irreversible,  greenhouse warming.

The proponents argue that there is significant evidence that CO2 levels have risen faster since industrialization than any time in the geologic record, and that the temperature and climate profile are consistent with rising temperatures induced by GHG’s. Increased energy in the atmosphere could not only lead to rising temperatures, but increased storm activity, melting ice caps, increasing sea levels, and ultimately economic disaster and the displacement of a significant portion of humanity.

The naysayers claim that the evidence is inconclusive (at best) or nonexistant (at worst). Further, they argue that Global Warming Propagandists (or “Warmers”) are threatening global economic stability for personal agenda, or even personal gain.

Significant fuel for this dispute was tossed into the flames this week with the “hacking” of emails and data files from the University of East Anglia Climate Reasearch Unit (CRU). Selected exerpts mention using “tricks” in the data, and “hiding” a decline in temperatures. Sites sharing this information – purporting to blow the whistle – go over the top with rhetoric about how ALL of climate research from “warmers” and alarmists can immediately be dismissed because of clear evidence of fraud and conspiracy.

Folks, chill.

This leak of private information in no way informs the debate. None. This is private communication, out of context, taken illegally. Third party interpretation and trumpeting is not even remotely reliable. Why? because those spreading the files have as much of an agenda as they purport the “warmists” to have. Innuendo and quote mining is not the way to win an argument upon which the future of humanity may rest. Sorry, but it’s not.

There are legitimate scientific questions still outstanding about climate change, because we don’t have a control earth to compare with. But the venue to resolve those problems is in the scientific literature, not FOX news. But, you cry, how can we trust the Warmist conspirators to allow unbiased peer review? Well, the criminal responsible for stealing and publishing the CRU files has seen to that. Climate research will now undergo an extra-thorough level of review, simply because everyone is watching. Carefully. Of course, that goes for all climate research, including that indicating minimal anthropogenic effect. So perhaps the theft will have a beneficial effect in that scrutiny will be even more thorough (not that it wasn’t before), but perhaps it will also delay important research.

In the end, I suspect nothing useful will come from the stolen files, but the potential for setbacks to important research is significant.


Science. It works.

November 23, 2009

Love it.