Make Room! Make Room!

There is a recent article in Phys Rev Letters (“Programed Death is Favored by Natural Selection in Spatial Systems”) arguing that aging is an adaptation – natural selection has favored mechanisms that get rid of useless old farts.  I can think of other people that have  argued for this – some pretty smart cookies (August Weismann, for example, although he later abandoned the idea) and at the other end of the spectrum utter loons like Martin Blaser.

If this were the case, it would be a good thing, because we could then hope to significantly extend the human lifespan just by interfering with key steps in the programmed aging mechanism.

We would be able to easily identify those key steps because of natural experiments – people born with mutations that screwed up their kill switch and therefore lived lots longer than normal – you know, like those inventions that get released by mistake (the gasoline pill, the 100 mpg carburetor, etc.) .  The problem is, I  have never heard of any such slow-aging genetic syndrome. I don’t think any exist in humans. Too bad.  And humans are the species to look at – not just because we hope to apply this to humans, but also because we know an enormous amount about human genetics.  Milo of Crotona couldn’t lift a current paper edition of OMIM .

On the other hand, there may well be cases in which something like this happens in other species, particularly in semelparous organisms – those that reproduce only once, like Pacific salmon. Normally those salmon go back to their original spawning grounds, breed and die. In dying, they create a nutrient-rich environment for their off spring, and for other offspring that are on average closely related.  You can see how programmed death might pay off in this case. A simple change does slow down senescence in those salmon: castration before they flame out triples their life span.

There might could be mutations that significantly extended lifespan but had consequences that were bad for fitness, at least in past environments –  but that isn’t too likely if mutational accumulation and antagonistic pleiotropy are the key drivers of senescence in humans. As I said, we’ve never seen any.

It is possible that old people were once useful (materially contributed to the fitness of near relatives), especially in preliterate days.  Back in the ice age climate could change rapidly (Dansgaard-Oeschger  cycles) – old farts may have remembered previous climates, and that might have been useful.  When Peter Panum studied the 1846 measles epidemic in the Faeroes, he found that quarantine could prevent contagion – but  the old farts that had lived through the 1781 epidemic already knew that. People who listened to them, about a quarter of the population, were shielded from the epidemic.

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Inverse weathervanes

I was thinking about something Razib Khan said – that sociology  is useful, because it has negative predictive value.  He’s probably right, but when you think about it, that’s odd. There are a lot more possible wrong theories than right ones  – which means that identifying the right theories is difficult.  Identifying anti-correct theories, exact negatives of the truth,  should be just as difficult. Perverse, too, of course, but who’s counting?

Considering that sociologists typically deny the very existence of some of the most important causal factors on human behavior (like genetics), you’d think their theories would make about as much sense as Galenic medicine or Freudian psychology – not even wrong.  Their theories should not make antisense – more like random nonsense.

Probably they manage this by denying experience.  Experience can show that a method works centuries before anyone has a correct theory of why it works.   There are things that your grandmother (and her grandmother) knew –  (the apple doesn’t fall  far from the tree, blood is thicker than water) –  and without those grannies,  sociologists wouldn’t know what to disbelieve.

 

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101 Eurasians

There is a new paper out in Nature, mostly about the spread of the Indo-Europeans.  They confirm that the Yamnaya ( from the Ukraine) were the main ancestors of the Corded Ware culture (northern Europe, from Germany far on east).  The Sintashta culture, (base of the Urals down to the Caspian, first with chariots, and ancestors of the Indo-Iranians), looks like a migration of Corded Ware to the east.

The Yamnaya were also the source of the Afansievo culture in the Altai, possible ancestors of the Tocharians.

The European lactose tolerance mutation is not common in the early Bronze Age, but it does exist, particularly in the Yamnaya, where the gene frequency is about 30% (in this study – zero in the Haak study) This suggests that the European mutation originated on the steppe (not Bavaria !) – which would explain why the same mutation is fairly common in northern India and Pakistan.  It’s not clear if it was common enough to have social and demographic significance back then – since it’s dominant, a gene frequency of 30% would mean that 51% of the Yamnaya were lactose tolerant. In other words, I said that I must be wrong about lactose tolerance mattering in the Indo-European expansion, but I am no longer sure about that.  But these samples are small – time to excavate more kurgans. Conceivably the frequency varied significantly by social class.  Anyhow, it had to have been spread by a massive invasion – it couldn’t have spread that fast as a Fisher wave.

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Antibiotic feed/food supplementation

Many domesticated animals show increased growth and improved feed efficiency when given low doses of antibiotics.  In fact, this is by far the biggest use of antibiotics.  Mostly you hear about this in the context of worries about how this may select for resistant bacteria (which may well be true), but one interesting question is why it even works – and what other applications this technique might have.

It strikes me that it might be useful in food emergencies – famines and so forth.  The dosage is low (200 g per ton) and can increase feed efficiency over 10% in some cases.  Assuming that antibiotic supplementation works in humans (which is likely, considering that it works in a wide spectrum of domestic animals), you might be able to save 5 or 10% more people with a given food supply. Now if we ever bothered to learn exactly how this works, we might be able to find an equivalent approach that didn’t use antibiotics, some other way of knocking out certain pathogens (phage therapy?) or altering the gut flora.

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Misreading One Letter

When I thought I saw the headline ” Ten Killer Apes You Can’t Do Without”, I was surprised, because off the top of my head, I could only think of three.

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Pre-K

I doubt if it will have much effect. Judging from twin studies, parenting effects are small or zero.  I doubt if preschool as we know it has stronger effects.

Of course we’ll do it anyhow.  Just for laughs, it would be nice if someone would develop a comprehensive account of similar efforts over the past couple of generations – and their outcomes.

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Mercs in Iraq

The Iraqi army we trained is totally useless – training doesn’t impart motivation. Not our kind of training, anyhow. So how  should the Iraqi government deal with the Islamic State?

The obvious answer is mercenaries, many of which already know Iraq pretty well.  The Iraqi government has sufficient oil revenues to pay the sort of force I’m thinking of; at least they would if they could just moderate the corruption for a while.  You’d want to hire the better sort of merc as far as you could – ex-US and British. Avoid bottom-feeders like Colombians.

Although ISIS is far more effective than the Iraqi  Army, they’re far less competent than any Western army. They have plenty of enthusiasm, but so did the Dervishes at Omdurman. It’s not enough.

Of course the Iraqi government hates Blackwater types (who doesn’t?) , and might well stab them in the back after they take care of the the enemy. Still, I think that they could take care of themselves.

Ten Thousand should be enough for the job.

 

 

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