File this post under "random quotations". The subject of this quote is the philosophical inquiry into cause and effect. I may have cited the book that the italicized bit below appears in, before in this blog, but I doubt I have referenced this particular passage. The more specific question under discussion is whether "natural selection" is an explanation of evolutionary change: that is, whether it names a cause of which the origin of a new species may be an effect. Suppose that to be a student in a certain classroom R, students must pass a test indicating that they read at the third-grade level. Some students A and B are admitted on the basis of this test, and others C and D are excluded. The use of this test amounts to a selection process, and the existence of this process explains, in one perfectly good respect, why it is true that "All of the students in room R read at the third-grade level." Nonetheless ... the existence of this selection process doe...
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Do we have direct introspective access into our own minds, or (if you believe in distinguishing, say, between ego and id) into some portion of our own minds? In The Opacity of Mind (2011), Peter Carruthers offered a "no," answer, along with an explanation of why we think we do. Carruthers argues that natural selection has bred into us an ability to read each other's minds. My ability to infer that an acquaintance is angry at me, and perhaps scheming up an ambush to kill me, is of obvious survival significance, and the gene lines that led to such an ability were naturally the ones that account for our dedicated mental subsystem for understanding one another. This system involves observations of behavior, facial expressions, tones of voice, etc. The SAME system, which of course relies upon behavior, facial expressions, etc., is also responsible for our understanding of our selves, Carruthers submits. There is no "inner sense" to it, though the subsyste...
As I said in yesterday's entry, Wade argues that the human race has continued to evolve subsequent to its spread across the eastern hemisphere. When it had spread, it was in effect divided into three habitats: Africa, east Asia, and 'the rest,' that is, all Eurasia west of the Himalayas. The geographical barriers were great enough to make further evolutionary (genetic) change a matter of divergence. From this situation arose distinctions among races/subspecies that are not "social constructs," but genetic facts. As the result of a period of climate change and melting ice caps, rising sea levels cut Australia off from East Asia, though allowing for a lot of "stepping stones" between. This allowed for the divergent development of the Aborigine people of Australia. Later, around 15,000 years ago, the northernmost east Asians, Siberians, crossed into the Americas. Some genetic divergence has arisen subsequent to that crossing, too. Thus, by the time...
My recent reading has included A Troublesome Inheritance (2014) by Nicholas Wade. Wade is an experienced science journalist -- he is a graduate of King's College, Cambridge, was deputy editor of Nature , and before going freelance he was both a reporter and an editor at The New York Times, where he wrote frequently about scientific and environmental matters. His book has the subtitle "Genes, Race, and Human History," which suffices to reveal how fraught is the subject matter. The point he wants to make is that biological evolution continues to change the human genome, and does so at time scales which are relevant to an understanding of history, not just dim pre-history. Evolution by natural selection isn't just about the fossil "Lucy" and her peers. It's about the fellow or gal in the mirror this morning. Evolutionary psychologists, he says, commonly "teach that the human mind is adapted to the conditions that prevailed at the end of the...
I'd like to congratulate the Wall Street Journal for running a recent opinion/analysis piece on the mysteries of yawning. In particular, the big one: "why is yawning contagious." People say, "the power of suggestion" but that sounds like a merely verbal answer, a bit like the claim that sleeping pills work because of their dormitive efficacy. A better approach, says the WSJ, is to think about survival effects. Yawning may have evolved as a way in which an organism maintains its alertness. It doesn't merely mean you're tired, it means that you are tired and recognize that you should be awake (in some non-moralistic sense of the word "should" of course.) This in turn suggests that the urge to yawn could well be triggered by the yawn of someone nearby. After all, alertness is a trait that small groups in close proximity often need to maintain together. They have common predators, or common prey, about.
Continuing... How has Taleb made his name? Look at the above graph. The blue line represents a normal or Gaussian distribution, also known as the "bell curve." Events on the far right or ar left side of that line, where the blue is approaching zero along the X axis, are sometimes call hundred-year storms. If we think of this in a finance/business context, the blue line may represent what a certain business thinks are its profits for the coming year. The tip of the bell represents the most likely result (a modest profit in line with that of most of its competitors, perhaps.) Toward the right end of the curve you get to ever higher but more unlikely profits, to the left you get losses, and then ever larger losses, though here too the fall-off in the line toward the zerobase of the X axis implies that certain disastrous results are very unlikely. But what if probabilities in finance don't have a normal outcome distribution? If you draw a flattened curve with "fa...