Why some like it hot: awesomeness

Mr. Jason Goldman has a post up, On Capsaicin: Why Do We Love to Eat Hot Peppers?. We don’t need no stinkin’ science for this. Do some ethnography with an N = 1: me. Those of us who love spicy food are just awesome! Recently I went to a Thai restaurant for the first time in 4 years which I used to frequent weekly in 2006-2007. Every Saturday I’d go and get a beef salad, which the chef would specially prepare for me by rubbing in a habanero paste into the meat ahead of time. That was the “four star” spicy level. When I reappeared after all this time the host exclaimed, “It’s Mr. four star!” Despite the years much of the staff which had been around back then remembered me. Back in the day sometimes they’d even watch me eat the dish to observe if I’d live to tell the tale. I can tell you similar stories from other restaurants. My very high spice tolerance threshold has reached such a level of virtuosity that people are often taken aback, and strangers will often comment upon it.

My point is that consumption of spicy food isn’t just a experience of the palette, it is deeply social. It is a signal of awesomeness, like having big antlers.

Here are some of Jason’s ideas:

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Modern humans in Arabia >100,000 years ago

The genetic model of the “Out of Africa” scenario is getting more complex. There may be two waves, as well as the likelihood of admixture between the Neo-Africans and “archaic” hominins, such the Neandertals and Denisovans. From what I can gather the genetic evidence is now converging upon the sequence of events where African populations diverge >100,000 years ago (e.g., a deep separation between the ancestors of the Bushmen and the ancestors of West Africans), and a radiation of non-Africans at most ~75,000 years ago, and more likely ~50,000 years ago. There are still many holes to be plugged in. While we’re waiting on genetics, here’s an interesting paper using archaeological methods in PLoS ONE, The Nubian Complex of Dhofar, Oman: An African Middle Stone Age Industry in Southern Arabia:

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On structure, variation, and race

I noticed yesterday that Andrew Sullivan, Ta-Nehisi Coates, and a cast of others were having a roiling debate on race and I.Q. My name came up in several comment threads on various issues. I’m aware of this because I have Google Alerts set for my name. I don’t have the time or energy to get immersed in this particular debate at this moment, but I did review some older material in the course of following links placed elsewhere. In particular, I encourage all of my newer readers to check out my friend Armand M. Leroi’s article in The New York Times from 2005, A Family Tree in Every Gene. Though dated in a few particulars (e.g., we know the locus responsible for most variation in blue eyes now, and it seems likely that Andaman Islanders and Malaysian Negritos are not the original settlers of their domains) I think the general outline has held up rather well. Compare it to the numerous vociferous responses over at SSRN. One wonders at the motivation for what seems like massive retaliation! Here are a few critical paragraphs from Armand’s piece:

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Genetic Creationism

Carl Zimmer points me to a piece in a publication called GeneWatch, The Crumbling Pillars of Behavior Genetics. I won’t quote from it because it’s kind of a tired rehash of the confusions and misrepresentations found in The Great DNA Data Deficit: Are Genes for Disease a Mirage?, thoroughly refuted by Luke Jostins and Dan MacArthur (and others at Genomes Unzipped). As I have stated before this sort of attack on genetics is basically similar to Creationism. It’s overloaded with technical and scientific terminology bound to impress the public, but which is just used in a confusing manner, to the point where there’s a big overhead in trying to unpack the logic (as opposed to rhetoric) of the argument. I am broadly convinced that we should be very cautious about results which point to specific genes implicated in a complex trait. But, this is not the “bread & butter” of behavior genetics, which has always been about smoking out the relationship between genetic and phenotypic correlations, and therefore heritabilities. Additionally, as I’ve pointed out there are areas of genomics which are going to be a very important helpmate to quantitative genetic analyses. As noted in the piece behavior geneticists did turn out to be too optimistic about genomics as being relevant to their field. But, the main objections aren’t that novel, and the argument is a repetition of very old conflicts.

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More than models

Slate recently had a series up on the use of mice as “model organisms.” In particular, it put the spotlight of some limitations of extrapolating from a mouse to a man (or other species). This is in some ways biology’s “WEIRD” problem. There are always going to be obvious reasons why we’d want to use mice instead of elephants as model organisms, but we might be entering into an era when the fixation on a few species might abate at least somewhat. With that, I point you to a piece in The Scientist (in its final issue I believe), Beyond the Model – How next-generation sequencing technologies will drive a new era of research on non-model organisms:

Central goals of biology have always been to understand the basis for diversity within and among species, and to understand how the environment can influence the expression of different traits. These emerging genetic approaches enable studies in a greatly expanded number of organisms and potentially allow genetic approaches to be applied in natural habitats. The use of model organisms is not dead, however. The utilization of previously generated resources and continued development of model systems will support and facilitate research in non-models. But with the ability to address molecular mechanisms in the natural world, we can truly begin to understand how all of these factors interact to generate the biological diversity that motivated the early scientists and continues to inspire us today.

There is a reason for the hype that the 21st century will be to biology what the 20th was to physics.

COMMENTS NOTE: Any comment which misrepresents the material in this post will result in banning without warning. So you should probably stick to direct quotes in lieu of reformulations of what you perceive to be my intent in your own words. For example, if you start a sentence with “so what you’re trying to say….”, you’re probably going to get banned. I said what I tried or wanted to say in the post. Period.

When trees turn into brambles

Genetics is powerful. The origins of the field predate Gregor Mendel, and go further back to plain human common sense. Crude theories of inheritance in the 19th century gave way in the early 20th to Mendelism, which happens to be a very powerful formal system for predicting the patterns of transmission of information from generation to generation. But I suspect that the popular accolades showered upon genetics would be more muted if it were not for the concrete discovery of the biophysical medium of that pattern of inheritance, DNA. By visualizing strands of DNA packaged into chromosomes one can gain a substantive understanding of Mendelian processes previously somewhat abstracted (e.g., recombination). In concert with the centrality of genetics at the heart of evolutionary science has been the ascendance of its methods in the older field of systematics. The phylogenetic tree is not only intuitive, but it has concrete reality in the sequences of base pairs or structural elements within the genome.

Whatever skepticism there might be about the dynamic phenomenon of evolution, the material aspect of modern genetics rooted in molecular biology is one of he primary wedges by which one can introduce an element of doubt into minds of a skeptic. The correlation between phylogeny and sequence identity of organisms which were previously adduced to exhibit some sort of biological relationship on the tree of life can not be dismissed out of hand. But this mode of thinking has limits, albeit due to the quirks of human psychology.

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The New York Times on violence and Pinker

The New York Times has a short piece on Steven Pinker up. Nothing too new to long time followers of the man and his work. I would like to point readers to the fact that Steven Pinker has a F.A.Q. up for The Better Angels of Our Nature: Why Violence Has Declined. He links to my post, Relative angels and absolute demons, as supporting his dismissal of Elizabeth Kolbert’s review in The New Yorker. I have to admit that I find much, though not all, of the coverage of science in The New Yorker to exhibit some of the more annoying stereotypical caricatures of humanists when confronting the specter of natural philosophy.

I should also mention I started reading The Better Angels of Our Nature over Thanksgiving. I’m only ~20% through it, and probably won’t finish until Christmas season gets into high gear, but so far it’s a huge mess. In both a good way, and a bad way. The good way is that it’s incredibly rich in its bibliography, with fascinating facts strewn about the path of the narrative. The bad way is that so far it lacks the tightness of  The Blank Slate or The Language Instinct in terms of argument. This may change. Finally, I think I should mention that Pinker has already addressed some of the criticisms of his methodologies brought up in the comments sections of my posts. Those who have specific critiques probably should read the book, because he seems to try sincerely to address those. Or at least they should address those critiques to people who have bothered to read the book.