Monthly Archives: November 2013

Biology now has it’s own arXiv

When I have talked to colleagues in math and physics, I was jealous of the arXiv preprint system model. It always seemed a lot closer to the way someone would design institutions for  scientific publication for 21st-century (instead of 17th-century) technology. Now biologists have their own place to play.

Jon Wilkins with the details:

A Fortnight (or so) of Links – 13 Nov 2013

I am pretty far behind my regularish fortnight link posting.  These have really built up!

Our forefathers were fierce & our foremothers were faithful by Razib Khan at Gene Expression. Reports on a study by Maarten Larmuseau and colleagues that collected information about genetic inheritance (the Y-chromosome) with cultural inheritance (family surnames) in Flanders. They used this data estimated that the amount of cuckoldry in the population, and found it to be quite low.

Bigger groups mean complex cultures by Ed Yong. Two recent experimental studies are out this past fortnight (in Proc B and Nature) providing support for previous models showing that larger groups can maintain cultural traits better than smaller groups (ungated summary).

Such deep roots you have: How Little Red Riding Hood’s tale evolved by Alan Boyle at NBC News. I am skeptical of the claims made by the researchers made in the article. They use phylogenetic trees, which are commonly used to describe relationships between biological species, to analyze the origins of the Little Red Riding Hood story. Phylogenetic techniques are hard for culturally transmitted traits because there can be a lot  more information flow between branches than you can have gene flow between (sexually-reproducing) species  (this is called “reticulation,” see here for more). Modeling historical cultural change with modern data is tricky!

The tribesman who Facebook friended me by  Jonnie Hughes. To me, this has a few good anecdotes about how some cultural traits are adopted between societies more readily than others.

How many genetic ancestors do I have? Posted at UC Davis’s Coop Lab blog. One of my (many) nitpicks with the Di Vinci Code movie (though maybe the book was better) was that a person with Jesus as an genealogical ancestor was unlikely to have him as a genetic ancestor. This post explains why we have many more genealogical ancestors than genetic ancestors.

View From the Inside: How Gang Members Use Secret Codes by Eric Jankiewicz. When I was in fifth grade my teacher, Ms. Dye, used to confiscate notes passed between students in class and post them on the wall. In response, some students started writing their notes in code, which could not be read even if posted on the wall. But then I started breaking the codes and giving the decoded messages to the teacher to post on the wall next to the coded ones.  This story of a police officer who breaks prison gang codes reminded me of that. Still, I bet he is more popular in prison than I was in the fifth grade. (Ms. Dye eventually told me to stop breaking the codes, which I thought was weird at the time, but it was sweet of her to try to help me out.)

Remembering Wallace. John Hawks comments on an Andrew Berry post about the relative obscurity of Alfred Russel Wallace. He points out that Wallace is perhaps better known to anthropologists than biologists because of his willingness to discuss natural selection’s implication for humans before Darwin.

The Math Trick Behind MP3s, JPEGs, and Homer Simpson’s Face by Aatish Bhatia. Spoiler alert: the math trick is the Fourier transform. This is just awesome science writing.

Diagrams for hierarchical models: New drawing tool.  This looks really useful for hierarchical modelers.  I will take these over a coefficient table any day.

Why Zimbardo’s Prison Experiment Isn’t in My Textbook by Peter Gray at Psychology Today.

As always, it is a good idea to check out the weekly links at Evolving Economics [41, 40, 39].

Entertaining (in that internet sort-of way):

Winning “The Price Is Right.”  Ben Blatt makes a handy guide for maximizing your chances on all of the subgames on The Price is Right. I used to watch this show with my grandma all the time at the guide made me a little nostalgic (she used to complain when the prices didn’t match those at the local drugstore). My only quibble is that while the article is billed as a “guide to better bidding through game theory,” only a couple of the games (contestant’s row and the big wheel – those with more than one contestant) are properly “game theory.” The rest are more accurately described as “decision theory.” But this is just a quibble that distracts from the larger view that this may be exactly what the internet was invented for.

Why Wine Cries. An awesome science video.

Millions of Lines of Code. It reportedly takes 5 million lines of code to repair  How many is that?

How long do hard drives actually live?

Exploring The Invisible Universe That Lives On Us — And In Us. A video by Rob Stein at NPR about the microbiome.

Up all Night to Get Data.” A music-video parody by the UCSD Neuroscience program.

Would You Live in a Hexagonal House? Answer: yes.



“Death from a Distance” and Social Control

On Andrew Gelman’s blog he often reprints emails he receives and his responses when he thinks they may be interesting to his readers. This post will be my first attempt at that.  However, I once surprised a friend when congratulating him on his email being answered on Gelman’s blog. So, unlike Gelman, I plan to always ask permission first.

Ed LeGrand writes:

At the 2010 Human Evolution & Behavior Society meeting I met Paul Bingham, who discussed his ideas in his book, Death from a Distance. Intrigued, I bought and read it and have since wondered why I'm not hearing discussion of it in, since it sounds so reasonable.
Bingham's premise is that the evolution of weaponry goes hand-in-hand with the evolution of social size and the size of political systems (of course, there are hundreds of correlates!). As you mentioned, chimps need about a 4:1 advantage before attacking with a reasonable degree of safety. Bingham would point out that because of spatial limitations, not many more than 3-4 individuals can be involved in hand-to-hand combat against an opponent at a time. Because the victim may be large or skilled, there's a rather high risk that one of the attackers will get injured. Bingham views this attack from the standpoint of group members disciplining/punishing a transgressor. Once a method of killing from a distance (throwing rocks) developed, the odds changed dramatically. It now becomes much safer to punish transgressors. Rather than 3-5 group members trying to punish one person and suffering the real risk of physical injury (a 4:1 advantage for the attackers), they can administer punishment at a distance. Not only is it physical safer, but now there are 4 people throwing rocks at one person, who can throw one rock at 4 people (a 4^2:1 advantage). The farther away one can be from the transgressor, the more physical space there can be for discipliners. With the development of new weaponry, a group of 100 people can easily simultaneously send 100 arrows at a transgressor (or victim) while only 1 arrow gets sent back at the 100 people (a 100^2:1 safety factor for the attackers).  Bingham's book follows the development of weapons (spears, arrows, firearms, etc.) and notes that the advantage is greatly magnified. Bingham suggests that the size of the group/hierarchy is causally associated with the ability to control transgressors (or the ability of a dictator to control his subjects). In warfare, this ability to deliver death from a distance greatly increases the advantage of having the new technology. As a defense, the opponents without the most advanced weaponry have no choice but to join a larger group, and so on (I'm condensing a couple of hundred pages of argument and examples). The epitome of this is the advent of nuclear weapons where punishment of a whole country can be administered by the push of a button at great distance. Bingham pointed out that this has pushed the world into a huge single society. Drones aren't mentioned, but that's like the technology of a whole society being directed at specific transgressors from the safety of being on the other side of the globe.
Anyway, you may have heard of the conceptual model. If not, it's one to at least be aware of. I'd think the advantage of weaponry for easier and safer ability to effect punishment or to extend one's will would lend itself to interesting mathematical modeling.

My reply:

I had not heard of this specific thesis, but it reminds me of some of the ideas in Boehm’s Hierarchy in the Forest. Boehm’s story is actually somewhat opposite. He posits that human groups was once fairly similar to chimpanzee groups – physically dominant males were at the top of a social hierarchy and maintained their social status by, basically, brute strength against all challengers. Weaponry allowed less dominant individuals to effectively gang up on any would-be dominant male and invert the hierarchy – creating fairly egalitarian groups. In his story, death from a distance creates the conditions for less social control.

It seems like what should be important, in addition to total killing power, is how killing power is distributed. With Boehm’s chimpanzees and with the nuclear weapons in your example, power is concentrated in the elites (or there are elites because power is concentrated).  In Boehm’s egalitarian groups and in the bow-and-arrow example from your email, power is fairly widely distributed. I hadn’t really thought about it in terms of weaponry, but I think this is probably important for understanding the size of hierarchies.  I’ll check out Bingham’s book.