A mammalian gene pool can acquire at most 1 bit of information per generation.
Eliezer,
That's a very provocative, interestingly empirical, yet troublingly ambiguous statement. :)
I think it's important to note that evolution is very effective (within certain constraints) in figuring out ways to optimize not only genes but also genomes-- it seems probable that a large amount of said "bits" have been on the level of structural or mechanical optimizations.
These structural/mechanical optimizations might in turn involve mechanisms by which to use existing non-coding, "junk" DNA in various ways (which might, in some sense, effectively increase the "bit size" of a single adaption into the megabytes).
It may be telling that we haven't seen, in three billion years and given all the other genetic complexity out there, any organisms evolve a mechanism to clean the junk out of its DNA.
At any rate, I think your argument is interesting, and the topic is simply fascinating, but I take your numbers with a grain of salt. No offense.
Interesting series of articles. I like the theme.
Just a small observation-- you may define the origin of life outside the domain of evolution, but I think you could just as easily bring it under the umbrella of evolution, with discussion of replicator precursors such as chemical epicycles and whatnot. I see your point, but I think distancing evolution from such a question might be seen as 'passing the buck'.
This should not be surprising; genes have to do all their own work of spreading. There's no Evolution Fairy who can watch the gene pool and say, "Hm, that gene seems to be spreading rapidly - I should distribute it to everyone." In a human market economy, someone who is legitimately getting 20% returns on investment - especially if there's an obvious, clear mechanism behind it - can rapidly acquire more capital from other investors; and others will start duplicate enterprises. Genes have to spread without stock markets or banks or imitators - as if Henry Ford had to make one car, sell it, buy the parts for 1.01 more cars (on average), sell those cars, and keep doing this until he was up to a million cars.
Fantastic paragraph in a really interesting piece.
Then other evolutions don't imitate it. If snake evolution develops an amazing new venom, it doesn't help fox evolution or lion evolution.
The only nitpick would be the possible spread of genes through horizontal gene transfer, but in mammals that seems like it would be trivial in most any sense of the word.