Friday, 21 April 2017

Daniel Dennett: If Brains are Computers, Who Designs the Software?

2017 talk by Daniel. There are plenty of memes in the second half of the video.

The following QA is available here.

Friday, 14 April 2017

Competitive adaptations

Evolution is notoriously a competitive business. Some adaptations have evolved for the specific purpose of doing-in competitors. There are many adaptations for male combat whose main function is doing in other males. The enlarged claws of male fiddler crabs are mainly used in combat with other males, for example. Male stag beetles also have similar competitive adaptations in the form of their claws.

Many plants do similar things. Black walnut trees load their roots and nut hulls with a toxin which seeps into the soil and kills or damages competing trees and plants. Many conifers line the ground around them with a thick blanket of needles which acts to suppress competitors. Some load the blanket with flammable resin, encouraging regular forest fires which only large, mature trees can survive.

Competitive adaptations are also common in cultural evolution. Some examples:

  • "Thou shalt have no gods before me" is a famous example from Christianity.
  • The Bible also features a prohibition on idolatry, with a similar intent:

    You shall not make for yourself an idol, or any likeness of what is in heaven above or on the earth beneath or in the water under the earth. "You shall not worship them or serve them; for I, the LORD your God, am a jealous God, visiting the iniquity of the fathers on the children, on the third and the fourth generations of those who hate Me, but showing loving kindness to thousands, to those who love Me and keep My commandments.
  • One way of exterminating the competition is killing their human hosts. Islam has plenty of examples of this with its holy war on infidels and repeated calls to violent action against unbelievers.

  • American elections heavily feature negative advertising, whose sole purpose is destroying the competition. For a famous example see the daisy girl video.

  • There are so-called Anti-competitive practices whose function is to eliminate competition. These are actually forms of competition in which organizations sabotage their competitors in various ways - often in the hope of eliminating the competition altogether and gaining a monopoly.

Sunday, 9 April 2017

Ubiquitous parasites

Bill Hamilton famously was one of the first evolutionary biologists to take parasites seriously - seeing their influence everywhere. Many have subsequently followed in his footsteps. One interesting paper on the topic which I recently took in is this one:

Gregory Cochran may be known to readers of this blog because he co-authored the book The 10,000 Year Explosion: How Civilization Accelerated Human Evolution. The paper here argues that pathogens have been consistently underestimated, and we ought to be considering them more frequently in cases where fitness is adversely affected.

The paper is all about organic pathogens. However the authors appear to be ignorant of cultural evolution, and don't extend their argument to cultural pathogens. Nor is there any discussion of meme-gene coevolution. Despite this, many of the arguments they give are equally applicable to cultural evolution.

One of the examples the paper gives is human male homosexuality. Although to date, no pathogen has been discovered that causes human male homosexuality, there's circumstantial evidence that suggests that pathogens may be involved. While thinking about cultural evolution it occurred to me that there's an example of cultural pathogens causing homosexual interactions between males: the well-known case of priests and altar boys.

It's long been argued that religious memes can sterilize priests to divert resources from genes to memes and thus promote their own propagation. Dawkins (1976) gives this argument as a hypothetical example. Homosexuality could be being promoted by memes for similar reasons. Though courtship and mating do use some resources, homosexual relationships do mostly manage to skip the cost of producing children - the resources saved could go into meme propagation.

Priests seem to go for young boys (rather than young girls) about 80-90% of the time. Indeed, the church apparently seems to be an attractive institution for homosexual men and many priests are gay. However the frequency of gay priests doesn't explain the frequency with which boys are targeted. Perhaps young girls are better guarded, or maybe they are more clearly prohibited for priests in scripture. Anyway the evidence is not conclusive, but memes do appear to be promoting male homosexual behavior in this case.

Knowledge of cultural evolution is invaluable in understanding the role of pathogens on human health. Consider the obesity epidemic, for example. That's an epidemic of Candida Albicans - and other fatness-promoting gut microbes. However it is also an epidemic of food processing technology and fast-food advertising memes. The food industrial complex develops ever-evolving tasty recipes and then uses memes as targeted vectors to deliver their their fat-promoting messages to consumers. The effects of memes and genes are tangled together in this case. Without an understanding of both you don't get the full picture.

Saturday, 8 April 2017

Symbiont consensus

In a 2016 post titled Shared interests of unrelated symbionts I discussed how unrelated symbionts often had shared interests, resulting in them pulling their hosts in similar directions.

A classic example of this involves promoting interactions between hosts. In the organic realm, rabies makes hosts want to bite each other while toxoplasmosis makes hosts unafraid of each other and attracted to each other's urine. In the cultural realm, missionaries seek out potential converts and teachers seek out pupils. In each case interactions between hosts are promoted by symbionts - because they need such interactions to reproduce.

Another example is reduced fertility. Many parasites compromise host fertility - probably since host reproduction uses resources which might otherwise go into symbiont reproduction. Many parasites go in for complete host castration - they are called "parasitic castrators". Many cultural symbionts also reduce host fertility - as seen in the demographic transition. Places like Japan where there are many memes have sub-replacement fertility.

This post is mainly proposing terminology. I think we should call these shared interests a "consensus". It's the consensus of the symbionts that the hosts should get out more, meet more strangers and not have kids of their own. Of course, "consensus" is not meant literally here: no-one is suggesting that the symbionts communicate via town meetings. The consensus might be different depending on which group of symbionts are under consideration. Gut bacteria might have a consensus that the host should go the the smallest room more frequently and spend more time there - while cultural symbionts might have a quite different consensus. We could call the cultural symbiont consensus the "memetic consensus" for short.