All of gcochran's Comments + Replies

Obviously you can limit travel in any way you want: you can let health workers go in and out while blocking regular travelers. Or, for that matter, you could block everyone under 20, everyone over 40, and everyone called Murphy. It does not have to be all or nothing.

If you were trying to make sense, you would let health workers fly in and quarantine them for three weeks on the way back: that's not much of an inconvenience, considering the risk. And you wouldn't let locals fly elsewhere for the duration.

" Liberia" was short hand: I mean the several countries in West Africa where the epidemic exists.

You know, discussions in this forum have a truly unusual flavor.

That assumes that you have good data real time data about the epidemic. If you start strongly punishing countries for revealing data about local epidemics you soon don't have that data anymore. As the article describes the one person who actually did spread the disease to the West was the nurse Teresa Romero Ramos. Health workers are much more likely to come into contact with bodily fluids and get the virus than the average person wealthy enough to buy plane tickets.

Purges in Cambodia might have changed average genotypes because they hit such a high fraction of the population. Generally it's hard to change things much in one generation, though - particularly because of loose correlations between genotypes and dreadful political fates. In the future dictators should be better at this. Now if Stalin had taken all the smartest people in the Soviet Union and forcibly paired them up, artificially inflating assortative mating for intelligence, you would have seen an effect. If you were a billionaire, you could maybe bribe people into something similar.

Paabo seems to think it unlikely that any of these introgressed alleles had a a significant selective advantage in humans, but that's unlikely. I'll bet money on this.

To be fair, I should explain why that is a sucker bet. John Hawks and I discussed about a situation with just a few tens of matings over all time: we were making the point that even in that minimal scenario, alleles with large advantages (on the order of 5%) could jump over to modern humans. The Max Planck estimate of 2% Neanderthal admixture is far more favorable to introgression: with that... (read more)

 There are sub-patterns.   There are facts about natural selection that every plant geneticist knows that few human geneticists will accept without a fight.  I mean, really, Henry, when a prominent human geneticist says " You don't really believe that bit about lactase persistence being selected, do you?" , or when someone even more famous asks "So why would there be more mutations in a bigger population?"  -  their minds ain't right. 
Could you expand on that?

I would say that it is some sense obvious that higher intelligence is possible, because the process that led to whatever intelligence we have was haphazard (path-dependent, stochastic, and all that) and because what optimization did occur was under severe constraints - some of which no longer apply. Clearly, the best possible performance under severe constraints is inferior to the best possible with fewer constraints.

So, if C-sections allow baby heads to get bigger, or if calories are freely available today, changes in brain development that take ad... (read more)

Thanks for the response. (Consider the following question in a Bayesian spirit, i.e. the spirit of giving a probability to any event, even if you don't have an associated frequency for it) If you had to bet on whether the technology for these genetic engineering efforts (NOT the political will) will be ready by e.g. 2030, 2040, 2050, 2075, 2125, what kind of odds/probabilities would you bet at?
I have heard of the theory that the human with the "consensus" genome would be way above average in phenotype. any idea how much?
I think that this comment highlights the fact that SIAI has a major brand management problem: SIAI is not concerned with "acceleration" of "progress", but with the development of smarter-that-human AI -- which could occur at a point in time where technology and economic indicators show growth, stagnation or even decline. But those who push the "acceleration" of "progress" brand, have about 10^3 times our marketing budget. No disrespect to Gregory -- it is simply the case that the marketing and info that's out there has turned the "Singularity" brand sour -- the term has lost any precise meaning.

Too random to have much effect, I should think. And at the same time, not awful enough to reduce the population to the point where drift would become important. Unless we're talking asteroid impacts.

One can imagine exceptions. For example, if alleles that gave resistance to some deadly plague had negative side effects on intelligence, then you'd see an effect. Note that negative side effects are much more likely than positive side effects.

I know of some neat anecdotal exceptions. Von Neumann got out of Germany in 1930, while the getting wa... (read more)

Hawks and I were talking about new genetic studies that showed a surprising number of sweeps, more than you'd expect from the long-term rate of change - and simultaneously noticed that there sure are a lot more people then there used to be - all potential mutants.

As for why someone didn't point this out earlier - say in 1930, when key results were available - I blame bad traditions in biology. Biologists mostly don't believe in theory: even when its predictions come true, they're not impressed.

My advantage, at least in part, comes from have ha... (read more)

Because theory in the field is so often wrong that they treat successes as a stopped clock being right twice a day? Or something more complex?
 Better hunting techniques can significantly raise Malthusian limits. 

First, you have to remember that old-fashioned humans were one predator among many: improved hunting techniques could raise our share of the pot, as well as decreasing other predators' tendency to eat us. Also, modern humans seem to have used carcasses more efficiently than Neanderthals: they had permafrost storage pits and drying racks, so could have preserved meat for long periods. Neanderthals didn't, and I think they must have wasted a lot. Next, moderns used snares, ... (read more)