Aug 25

Lo que separa la civilización de la anarquía son solo siete comidas.
– Spanish Proverb

Quoted in “The Coming Famine” by Julian Cribb

With eloquent symbolism, this Petronian banquet made clear that the well-off part of humanity has largely forgotten what it is to go hungry and is awakening to an unpleasant shock: starvation and the wars, refugee crises, and collapse of nation-states that often accompany hunger have not been permanently banished after all. Indeed, they are once more at our doorstep. Food insecurity and its deadly consequences are again a pressing concern for every nation and each individual.

FYI, the proverb translated is: Civilization and anarchy are only seven meals apart

Feb 17

“The research, published by the journal Molecular Systems Biology, shows that when an ageing cell detects serious damage to its DNA – caused by the wear and tear of life – it sends out specific internal signals. These distress signals trigger the cell’s mitochondria, its tiny energy-producing power packs, to make oxidising ‘free radical’ molecules, which in turn tell the cell either to destroy itself or to stop dividing. The aim is to avoid the damaged DNA that causes cancer.”

Jan 13

I was lucky to have followed the link in my Freakanomics RSS feed to listen to a talk by Dr. Craig Feied.

The key point made by Dr. Feied is that the amalgamation and analysis of wide ranging data – including from the emergent fields of genomics, proteomics, metabolomics, etc. – within computer models could foster a much better, and possibly, as forecasted by the current trendlines, a complete understanding of human ailments.

Dr. Feied’s talk begins at 37:50:

Sep 04

“Big Brian” is not as easy to digest as Matt Ridley’s well-written, lucid “The Red Queen”, but promises an intriguing analysis in the “origins and future of human intelligence”. This book continues in the theme of my personal exploration in the areas of Genetics, Evolutionary Biology and Evolutionary Psychology.

Big Brain - Book Cover

Big Brain - Book Cover

Here’s a snippet from Chapter 3, which summarizes the reason for the remainder of the book:

We may think of brains as good things; big brains make smarter animals, so surely evolution wants to increase brain size. But brains are expensive.

So the argument goes: if these highly expensive parts are being expanded, the results must be valuable indeed.

As a result, it is often hypothesized that each brain size increase during primate evolution must have been strongly selected for, i.e., there must have been some strong behavioral improvement that made the brain increase advantageous in the fight for survival.

We posit quite a different hypothesis: that brains increase for biological reasons – which may be largely accidental – and that behaviors follow this increase … a big brain got randomly tossed onto the table and once there, it found utility.

modest and understandable gene variations stumbled onto these useful but relatively humble modifications.”

UPDATE: Finished the book. While the subject matter is good, the book could be better. I felt the organization of the book and the images were poor. But the “big picture” presented by the authors is interesting: that animal brains appear to have changed little, except for size and the associated plumbing. But the authors claim that this extra size allows the brain to elastically assume higher level functions. Key in their discussion is that there have been three large dislocations in brain size growth within our family: 2-4M years ago with Australopithecines, 500K-2M years ago with home habilis/erectus and then finally, most recently, to homo sapiens – amazingly, these changes in size fall linearly in place on a log graph of frontal area (mm3) vs. brain weight (mg x 1000).

Aug 08
It’s not exactly light summer reading, but I’m very glad that I selected “The Red Queen” by Matt Ridley. It goes well with the online genetics course that I’ve been working through. Here’s a great excerpt from Chapter 6 [UPDATE – 090830: which, incidentally, servies as a great summary of the book]:
… Evolution is more about reproduction of the fittest than survival of the fittest; every creature on earth is the product of a series of historical battles between parasites and hosts, between genes and other genes, between members of the same species, between members of one gender in competition for members of the other gender. Those battles include pyschological ones, to manipulate and exploit other members of the species; they are never won, for success in one generation only ensures that the foes of the next generation are fitter to fight harder. Life is a Sisyphean race, run ever faster towards a finish line that is merely the start of the next race.
Here’s an interview with Matt Ridley that gives a sneak peak into “The Red Queen” and few of his other books:

UPDATE – 090830: Finished the book today. To Ridley, the human brain as an ornament, much like the peacock’s plummage. He theorizes, with support from others, including Geoffrey Miller, that the human brains ‘frenzied’ growth of the neocortex is the result of sexual selection, favoring the use of the brain as an instrument of attracting, manipulating, suspecting, etc. – not just as an instrument for walking, talking, tool making or hunting.

Aug 03

Excellent post by the On Gravity and Levity blog discussing the actuarially inspired “Gompertz Law of human mortality”, which predicts the probability of dying during a given year doubles every 8 years.

Below are some statistics for mortality rates in the United States in 2005, as reported by the US Census Bureau (and displayed by Wolfram Alpha):

usa-death_rates

This data fits the Gompertz law almost perfectly, with death rates doubling every 8 years.  The graph on the right also agrees with the Gompertz law, and you can see the precipitous fall in survival rates starting at age 80 or so.  That decline is no joke; the sharp fall in survival rates can be expressed mathematically as an exponential within an exponential:

P(t) \approx e^{-0.003 e^{(t-25)/10}}

Exponential decay is sharp, but an exponential within an exponential is so sharp that I can say with 99.999999% certainty that no human will ever live to the age of 130.  (Ignoring, of course, the upward shift in the lifetime distribution that will result from future medical advances)

Especially intriguing is the ending of the article – in which the author discusses a “cops and criminal” model and leads to a discussion on telomere shortening. It would be interesting to see if the telomere error rate is anywhere close to the Gompertz Law.

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