Stuff

First of all, I’ve made a decision to try not to post too often over the next 2 months. Blogging takes time, doing stuff that’s blog-worthy takes time. I have a couple of important exams coming up in January. I should not be spending any of my time on the stuff that I blog about here before those exams are behind me.

Next, a few links.

i. Dying Outside, by Hal Finney. His last update is more than a year old. According to wikipedia, he’s still alive.

ii. What is a gene “for”?

““Scientists discover gene for autism” (or ovarian cancer, or depression, cocaine addiction, obesity, happiness, height, schizophrenia… and whatever you’re having yourself). These are typical newspaper headlines (all from the last year) and all use the popular shorthand of “a gene for” something. In my view, this phrase is both lazy and deeply misleading and has caused widespread confusion about what genes are and do and about their influences on human traits and disease.” [...]

“While geneticists may know what they mean by the shorthand of “genes for” various traits, it is too easily taken in different, unintended ways. In particular, if there are genes “for” something, then many people infer that the something in question is also “for” something. For example, if there are “genes for homosexuality”, the inference is that homosexuality must somehow have been selected for, either currently or under some ancestral conditions. Even sophisticated thinkers like Richard Dawkins fall foul of this confusion – the apparent need to explain why a condition like homosexual orientation persists. Similar arguments are often advanced for depression or schizophrenia or autism – that maybe in ancestral environments, these conditions conferred some kind of selective advantage. That is one supposed explanation for why “genes for schizophrenia or autism” persist in the population.

Natural selection is a powerful force but that does not mean every genetic variation we see in humans was selected for, nor does it mean every condition affecting human psychology confers some selective advantage. In fact, mutations like those in the neuroligin genes are rapidly selected against in the population, due to the much lower average number of offspring of people carrying them. The problem is that new ones keep arising – in those genes and in thousands of other required to build the brain. By analogy, it is not beneficial for my car to break down – this fact does not require some teleological explanation. Breaking down occasionally in various ways is not a design feature – it is just that highly complex systems bring an associated higher risk due to possible failure of so many components.

So, just because the conditions persist at some level does not mean that the individual variants causing them do. Most of the mutations causing disease are probably very recent and will be rapidly selected against – they are not “for” anything.”

I have made a similar point in the past, probably more than once.

iii. Stuff you didn’t know about mine fires.

“Whether started by humans or by natural causes, coal seam fires continue to burn for decades or even centuries until either the fuel source is exhausted; a permanent groundwater table is encountered; the depth of the burn becomes greater than the ground’s capacity to subside and vent; or humans intervene. Because they burn underground, coal seam fires are extremely difficult and costly to extinguish, and are unlikely to be suppressed by rainfall.[1] There are strong similarities between coal fires and peat fires. [...] Many recent mine fires have started from people burning trash in a landfill that was in proximity to abandoned coal mines, including the much publicized Centralia, Pennsylvania, fire, which has been burning since 1962. Of the hundreds of mine fires in the United States burning today, most are found in the state of Pennsylvania. [...] It is estimated that Australia’s Burning Mountain, the oldest known coal fire, has burned for 6,000 years.”

In case you were in doubt, “Extinguishing underground coal fires, which sometimes exceed temperatures of 540°C (1,000°F), is both highly dangerous and very expensive.”

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This is probably as good a place as any to once again remind old readers, and to let new ones in on this fact, that this blog is not one of those blogs that’ll just ‘die’ without an explanation. If I decide to close the blog down, I’ll tell you. If I haven’t told you anything and I also don’t update either the blog or my twitter in weeks, the most likely explanation is that I’m dead or something along those lines.