Saturday, August 25, 2012

E.O. Wilson getting religion wrong

I just finished reading E.O. Wilson's The Social Conquest of Earth.  Written as it was for an educated yet not academically minded audience it is hardly surprising that I didn't learn much new from the book.  Nevertheless, it should serve as a handy reference for teaching in the future and I found it refreshing to see the multi-level selection approach so forcefully promoted even if, in some places, I believe Wilson overstated the case.  Unfortunately, Wilson makes a number of unwarranted and poorly informed attacks against religion.  In the future, I may take each of these in turn.  For the moment, however, I'd like to comment on one in particular since it touches on my own research.

Wilson makes a number of impassioned pleas toward the end of the book about the critical juncture the human species finds itself at.  As might be expected from a biologist, his loudest cries are for the state of the environment:

Sure one moral precept we can agree on is to stop destroying our birthplace, the only home humanity will ever have.

That's certainly a moral precept I can agree on and one that I feel rather strongly about as well.  However, Wilson goes on to say:

It will be useful in taking a second look at science and religion to understand the true nature of the search for objective truth.  Science is not just another enterprise like medicine or engineering or theology.  It is the wellspring of all the knowledge we have of the real world that can be tested and fitted into preexisting knowledge.  It is the arsenal of technologies and inferential mathematics needed to distinguish the true from the false.  It formulates the principles and formulas that tie all this knowledge together.  Science belongs to everybody.  Its constituent parts can be challenged by anybody in the world who has sufficient information to do so.  It is not just "another way of knowing" as often claimed, making it coequal with religious faith.  The conflict between scientific knowledge and the teachings of organized religions is irreconcilable.  The chasm will continue to widen and cause no end of trouble as long as religious leaders go on making unsupportable claims about supernatural causes of reality.

To put this into better perspective, Wilson just a few paragraphs earlier said:

Why, then, is it wise openly to question the myths and gods of organized religion?  Because they are stultifying and divisive.  Because each is just one version of a competing multitude of scenarios that possibly can be true.  Because they encourage ignorance, distract people from recognizing problems of the real world, and often lead them in wrong directions into disastrous actions.

So now we get to the heart of my objection.  As I read it, Wilson is essentially trying to lay the blame for environmental degradation at the feet of religion.  Moreover, he suggests that the only antidote to the destructive nature of religion's superstition is the cold rationality of the scientific enterprise.

This is particularly obnoxious to me because I have been working for the past year and a half on a project with some of Lin Ostrom's students that looks specifically at the relationship between religion and the management of natural resources.  We still have two more cases to code before we begin our analysis.  Nevertheless, it is clear from the 48 cases that we've looked at so far that religion has traditionally had extremely important roles to play in the sustainable use of resources.  For instance, religion often serves to define the physical boundaries of resources and marks those who are allowed to use them.  Religion serves monitoring functions and imposes sanctions for those who break the rules.  It also is an important source of perceived benefits that encourage users to cooperate with others.  Religion provides opportunities for leadership, repositories of local knowledge, calendars to coordinate cooperative efforts and avenues for the establishment and maintenance of social capital.  To say that religion in this context is "stultifying and divisive" is plain and simply wrong.  It is both highly innovative and creative and it leads to greater cooperation for an enterprise that is notoriously difficult.

Now, I can hear the objections already that religion is hardly necessary to provide these services.  This is a fair point.  Indeed, many groups do use secular alternatives to great effect.  Furthermore, many groups that we've studied employ a mixture of religious and secular mechanisms to govern their resources sustainably.  Nevertheless, the fact that religion is providing these vital functions should alone be enough to give us pause about actively working to undermine them.  At least it should give us pause if our primary goal is really better stewardship of the planet.  Religious means of encoding culturally important information may not be rational in the sense that Wilson and others understand that term.  They certainly weren't arrived at through a deliberate process of empirical research checked through peer review.  For that matter they often probably didn't arise as deliberate conservation efforts in the first place.  Many of them, however, have been in use for centuries and, as such, have been subjected to generations of cultural evolution which has produced finely tuned institutions, exquisitely sensitive to local environmental contexts.  Surely if biologists can't place any credence on supernatural entities and superstitious articulations of the way the world works they can at least give some respect for systems refined through natural selection!

Finally, religion is hardly unique in its ability "to distract people from recognizing problems of the real world," nor is it alone in leading "them in wrong directions into disastrous actions."  Time and again we have found cases in our work where the leading cause of the breakdown in sustainable resource management by user groups can be traced to either the privatization of the resource in question or, more often, to the usurpation of local user rights through nationalization.  In this latter case, national governments take over control of resources, eliminating any semblance of local autonomy and denying local users any collective choice rights to determine the rules they are expected to follow.  The results of this kind of policy are almost universally disastrous, leading to rapid environmental degradation.

And where did these policy notions come from?  It was decidedly not from the world's religions.  Rather, it came from western scientists and scholars whose thinking was summarized so concisely and compellingly in Hardin's Tragedy of the Commons.  This represents policy based on rational thought and enjoying strong empirical support from modeling studies and laboratory experiments.  In short, it represents exactly the sort of approach that Wilson touts as being inherently superior to the "unsupportable claims" of religious leaders.  It also happens to be completely and disastrously wrong as Elinor Ostrom's work has shown, work for which she earned a Nobel Prize.  I only hope that the damage caused by such superior, rational thinking can be repaired before it's too late for us all.

Thursday, August 23, 2012

Energy Rate Density, Fitness and Reproduction



As you (Ian and Yasha) know I have been struggling with the idea of differences between absolute and relative fitness. I just typed out something that just occurred to me. Let me know what you think. 

Not all traits/behavior may contribute to reproductive success. If we consider reproduction as a special case, then those traits become relevant that contribute to reproductive success as they can get selected and evolve. 

If reproduction does not occur in a system, then those traits will evolve (by means that do not specifically require reproduction/heredity) that contribute to...well just living and increasing/maintaining the bearers free energy rate density (Chaisson, 2011).

If the above has some meaning then bringing together the two ideas of "reproduction is a special case" and "is there a difference between absolute and relative fitness" leads you to this conclusion, traits that contribute to increasing free energy rate density can be broken down into two types those that rely on reproduction and thus contribute to increasing reproductive fitness and those that do not contribute to in any conceivable way to increasing reproductive fitness. 

In the second scenario those traits that rely on reproduction and contribute to a increase in reproductive fitness are traits that increase relative fitness of an organism in a population over time. 

The first scenario describes contribution of a trait to absolute fitness, where a trait might not have anything to do with reproduction or reproductive success. It just contributes to maximizing free energy rate density..just living. 
       
        References
         
        Chaisson, E. J. (2011). Energy rate density as a complexity metric and evolutionary driver. Complexity, 16(3), 27–40. doi:10.1002/cplx.20323

Wednesday, August 22, 2012

The meaning of the adaptation to tolerate lactose.


The question that is most often asked about lactose tolerance is that if drinking milk is an evolutionary adaptation shouldn't we continue to reap its fitness benefits? Although this question may be frowned upon by individuals who study evolutionary biology it is an important question to answer as it addresses the issues that  are important to understanding of evolution; adaptation and natural selection. 

I will explore this question in two parts first I will explain the adaptation of lactose tolerance and then I will explore how natural selection effects life history evolution. 

Is Lactose tolerance an adaptation? 

Lactose tolerance occurs due to a genetic mutation(s) that confers an ability to digest lactose from milk. Lactose tolerance appeared as a fortuitous mutation, yet it got selected as a result of the fitness benefits it conferred; it had beneficial effects on the adaptedness (absolute fitness) of individual humans within an environmental context. Natural selection then occurred as a result of differences in adaptedness of individuals within a specific population; i.e. some individuals could drink milk into adulthood whereas others couldn’t. Over time, those individuals that could drink milk into adulthood survived and reproduced at relatively higher rate than those who could not. Over many generations, through the process of adaptation the trait for digesting lactose became adaptive within a spatio-temporal context.

Even though the trait arose as a fortuitous mutation it became adaptive as it created differences in absolute fitness and set stage for natural selection to occur. Lactose tolerance gene was definitely an adaptation to milk drinking in the spatio-temporal context it evolved in; must this mean that this trait is as adaptive today as it was in our past? Does a trait’s noble legacy justify its credentials in the present? This may not always be true and the answer depends on the differences between past and present and the nature of life history evolution.

It is important at this point to understand that all adaptations have three aspects.

a) Historical; an adaptive trait is present today in an organism because it provided fitness benefits to its bearers and there was a selection for the adaptive trait.

b) Spatial: An adaptive trait is a specific solution to a problem posed by a feature of a given environment.

c) Eventual: Adaptive traits have the ability to confer (present and future) fitness benefits to its bearers.

Whether or not an adaptive trait persists through time depends on a number of factors; the environment being the most critical of them. If there are minimal changes in the environment (over evolutionary time) such that the plasticity allows the trait to persist, then the trait remains a legible solution to the problems posed by the environment. On the contrary, if the environment has changed substantially enough so that the plasticity of the trait does not buffer the changes, then the trait finds itself in uncharted waters. Sober pointed out in “The Nature of Selection” that “the benefits that account for a traits fixation need not persist into the present. “The benefits that account for a traits fixation” are governed by the environment (Sober, 1993).

If one considers just the historical aspect of an adaptive trait then “a trait can be an adaptation for performing some task, even though performing that task in the present environment confers no benefit” (Sober, 1993).
This statement can be misunderstood as the reader might comprehend that a traits noble legacy justifies it present credentials. An adaptive trait remains an adaptation no matter what happens. I would like to clarify what I think Sober meant for the reader to read between the lines; an adaptive trait remains an adaptive trait, retrospectively. A trait is an adaptation just because it was an adaptation in the spatial context it evolved. The trait conferred fitness benefits to its eventual bearers. The trait will still be called adaptive; the process which shaped the trait will still be called adaptation, but retrospectively. Whether an adaptive trait is adaptive today depends on the environmental context of the trait. If the environment is substantially different from the environment in which the trait evolved and became adaptive then the trait may not confer any fitness benefits (Remember that the trait is still adaptive but…you guessed it…retrospectively). If the environment changes, the trait remains adaptive looking at the past; whether the trait still persists as an adaptation in the future is another issue altogether.

There are three scenarios a trait may experience if the environment changes; a) the trait may not confer any fitness benefits, i.e. remain neutral and adaptive retrospectively; b) the trait may happen to confer fitness benefits, persist being adaptive; and c) the trait confers negative fitness benefits and become maladaptive.
Going back to the adaptive trait of Lactose tolerance, we can either say that Lactose tolerance was an adaptation in the spatio-temporal context that favored its prevalence or lactose tolerance is an adaptation retrospectively. Both statements are correct as long as you understand the definition of an adaptation. The question therefore is not whether lactose tolerance is an adaptation. It most definitely is! The question is whether lactose tolerance is an adaptation in today’s environmental context? 

In the arid climates of Middle and Near east dairy has been suggested to be the major source of clean uncontaminated water (Cook & Al-Torki, 1975). The individuals that could drink milk into adulthood happened to have higher relative fitness than those who could not. In northern Europe dairy was the source of calcium, this must have been crucial in place where there is very little sunlight (Flatz & Rotthauwe, 1973).
Thus the trait was selected and as the populations of individuals travelled across the world the trait travelled with them. In certain places the trait might have been still adaptive; yet, in other places the adaptive trait might have lost its relevant environmental context. Rehydration through consumption of dairy is not a necessity when you live next to a river, for example.

Thus we can say that in certain populations in the past (and today) the adaptive trait of lactose tolerance lost its relevance, as it could not confer fitness benefits. It is lingering in our gene pool as a consequence of fitness benefits it conferred to its bearers in their environmental context. Those fitness benefits are not relevant in those populations whose environmental context has changed. Thus lactose tolerance does not remain an adaptation in those populations; however, that does not take away the adaptive legacy of the trait. The trait has become a not-so-benign ghost of Christmas past.

Lactose Tolerance is a mal-adaptation

Now that I have established that a trait can lose its adaptive significance in a changed environmental context I will try to make the case that this trait is not just a neutral adaptation but has the potential to be transformed into a mal-adaptation in todays environmental context. Lactose tolerance and the resultant consumption of milk have been linked to many chronic diseases of the western civilization. Chronic consumption of milk has been associated primarily with auto-immune diseases (Type 1 Diabetes, Rheumatoid Arthritis, and Multiple Sclerosis) (Elliott, Harris, Hill, Bibby, & Wasmuth, 1999; Malosse, Perron, Sasco, & Seigneurin, 1992), consumption of dairy has also been correlated to prostate cancer and insulin resistance (Pereira et al., 2002; Qin et al., 2004). The ghost-adaptation of lactose tolerance is making us realize the necessity of changing our ways (I couldn’t help myself there ). Lactose tolerance today is a mal-adaptation as the trait was previously selected for by natural selection, lost its relevance, and now is becoming a crucial factor in the development of chronic diseases.

Natural Selection and Life History Evolution

There is another important aspect to the “adaptation” of consuming dairy into adulthood. It is centered on the workings of natural selection.

Natural selection operates most quickly on traits and behaviors that are expressed during the reproductive years of the life cycle. A trait that hampers reproductive ability in the young will be quickly eliminated from the population. A trait that is expressed in the in the older individuals will be removed much more slowly. As lactose tolerance was beneficial for individuals within a certain environmental context it got selected irrespective of the long-term effect it caused.

The following table may help to explain which traits get naturally selected. Traits and adaptations may have in all four aspects: a) short term benefit, b) short term cost, c) long term benefit, and d) long term cost



Traits that have short (during reproductive years) and long term benefits (longevity) will get naturally selected so will traits that have short term benefit and a long term cost. Traits with short term cost will get weeded out if they negatively affect an organisms’ fit with the environment. Lactose tolerance, in todays changed environmental contexts falls into the category of traits that have short term benefit and long term cost.

Summary

Thus, the question, “if lactose tolerance is an adaptation shouldn’t we continue to drink milk?” has two sub-questions. First, is lactose tolerance an adaptation in todays environmental context? And second aspect deals with nature of life history evolution and natural selection. The answer to the first question tell us that lactose tolerance is does not remain an adaptation in a changed environmental context, moreover it has become a mal-adaptation due to enabling of chronic consumption of milk. Dairy consumption has been correlated locally as well as globally with many diseases of civilization. The answer to the second question addresses the issue that a trait that confers fitness benefits in reproductive life will tend to get selected even though it has long term costs.

Summary Statement: Lactose tolerance is a retrospective adaptation that has the potential to become mal-adaptive in a changed environmental context. 

References

Cook, G. C., & Al-Torki, M. T. (1975). High intestinal lactase concentrations in adult Arbs in Saudi Arabia. British Medical Journal, 3(5976), 135–136.

Elliott, R. B., Harris, D. P., Hill, J. P., Bibby, N. J., & Wasmuth, H. E. (1999). Type I (insulin-dependent) diabetes mellitus and cow milk: casein variant consumption. Diabetologia, 42(3), 292–296.

Flatz, G., & Rotthauwe, H. W. (1973). Lactose nutrition and natural selection. The Lancet, 302(7820), 76–77.

Malosse, D., Perron, H., Sasco, A., & Seigneurin, J. M. (1992). Correlation between milk and dairy product consumption and multiple sclerosis prevalence: a worldwide study. Neuroepidemiology, 11(4-6), 304–312.

Pereira, M. A., Jacobs Jr, D. R., Van Horn, L., Slattery, M. L., Kartashov, A. I., & Ludwig, D. S. (2002). 

Dairy consumption, obesity, and the insulin resistance syndrome in young adults. JAMA: the journal of the American Medical Association, 287(16), 2081–2089.

Qin, L.-Q., Xu, J.-Y., Wang, P.-Y., Kaneko, T., Hoshi, K., & Sato, A. (2004). Milk Consumption Is a Risk Factor for Prostate Cancer: Meta-Analysis of Case-Control Studies. Nutrition and Cancer, 48(1), 22–27. doi:10.1207/s15327914nc4801_4

Sober, E. (1993). The nature of selection: evolutionary theory in philosophical focus. University of Chicago Press. Retrieved from http://books.google.com/books?hl=en&lr=&id=6bLZQzDd0f4C&oi=fnd&pg=PR9&dq=nature+of+selection&ots=NqnNZ0V_xs&sig=yt2t6n05ZurIb8JigyFXDenPRVE

Saturday, July 14, 2012

Why we still wear pants


Peter Turchin recently published a series of blogs (part 1 and part 2) addressing the question of why westerners wear pants.  It's a story I'd heard before years ago in a comparative Indo-European studies course, but not from an expressly evolutionary perspective and not with Peter's flare.  It's a good story, particularly for introducing cultural evolution, and I don't want to spoil it for those who haven't heard it before.  Nevertheless, not much about this post will make sense if I don't at least mention that wearing pants came about whenever riding horses became an important part of warfare.

As much as I like the story, I made what I thought was a somewhat innocuous comment saying that I would like to see a follow up series of blogs that explored why we still wear pants.  After all, very few people ride horses and, aside from some special exceptions, horse cavalry became obsolete in World War 1.  However, not only has the wearing of pants continued, it has spread, both to societies we've come into contact with and to women within our own society.  This spread has happened without any obvious adaptive advantage.  Moreover, this persistence and spread has occurred despite available alternatives and social movements, such as the androgynous movement of the 1980s, that attempted, and failed, to change these established practices.

Peter's response to this question, while not exactly surprising, was surprisingly dismissive.  His position is that there is no need to explain when cultural traits fail to change.  For him, the lack of change is the null hypothesis.  In his own words:

The null model is dp/dt = 0, where p is the frequency of the trait, and dp/dt it’s (sic) rate of change. If there is change, then dp/dt = c, or dp/dt = cp, depending on the details of how the trait changes. In any case, the greater the rate parameter, c, the faster the trait will change. So if c is high enough you will have yearly changes of fashion, if c is small enough, then it will take decades or even centuries.

The failure of something to change, in Peter's view as I understand it, can simply be dismissed as normal inheritance.  In the absence of variation and/or in the absence of selection pressure to change, we simply go on as we've always done.

I object to this position on a number of fronts.  To begin, it appears to be an assumption, not an empirically established fact.  Moreover, all these equations really establish is that some traits change faster than others, hardly a startling revelation.  What they fail utterly to do is account for why some traits change faster than others.  The salient question, for me, is why dp/dt should ever be zero, or even near zero. 

It is, of course, entirely plausible that Peter is right, that the failure of this particular trait to change might be due to simple inertial processes.  However, this is far from the only possibility.  We need only look to biological systems to see why this is so.  Robustness, the propensity of a system to continue functioning in the face of perturbation, is a general property of complex, evolved systems.  The structure of DNA and the genetic code are robust to mutations.  Proteins similarly tend to perform their functions even with amino acid substitutions.  This robustness is evident all the way up the hierarchy of biological complexity.  Even developmental systems are robust to changes in metabolic pathways. 

I see no logical reason to assume this general property of biological systems, a property that is an adaptation in its own right, should somehow no longer hold true once the level of complexity moves outside the skin of the individual organism.  Moreover, if evolutionary approaches to understanding human culture are to meet their full potential, they must grapple with practical problems in the current world, many of which represent historical patterns from which groups seem almost incapable of escaping.  For instance, Nisbett andCohen have traced modern rates of male violence in the southern United States to Celtic herding cultures, an ancestral pattern that has persisted long after herding faded out as a way of life.  Similarly, Robert Putnam has traced failures of democratic institutions in southern Italy to patterns of social capital building that go back 500 years.

Treating the persistence of these problems as nothing more than null hypotheses drastically reduces the chances of finding real solutions.  Aside from blinding ourselves to the root causes of recalcitrance, robustness paradoxically makes evolvability possible.  A handful of textbook examples notwithstanding, it is rare for a single mutation in biological systems to be adaptive.  Most often, adaptations arise from a series of mutations.  Fragile systems, however, are relatively incapable of building pools of useful variation since any slight change is likely to lead to suboptimal performance.  Robust systems, by contrast, tend to build up pools of variation, some combination of which may prove adaptive when new niches present themselves or existing environmental conditions change.

As for the question that ultimately motivated this post, I have no idea why we are still wearing pants.  If I were to hazard a guess, I would say that once pants became associated with warrior castes they acquired protection by virtue of prestige bias.  This in itself, though, might not have been enough to ensure the practice persisted.  More likely, the wearing of pants started to get tied to concepts in addition to warrior attire.  For instance, pants became associated with markers of gender identity, group heritage, etc.  In other words, it became connected to many other cultural constructs in intricate webs not unlike the way genes often have pleiotropic effects in gene networks.  If so, then wearing pants could become difficult to change even if there were compelling reasons to do so.

Sure, this is all purely conjecture at this point.  However, it hopefully goes some ways toward demonstrating that lack of change is a worthy subject for evolutionary study.

Saturday, June 16, 2012

Those who help themselves

There was another strand to the conversation I had with Michael Dowd and Connie Barlow the other day that bears consideration.  Namely, the subject of what services churches offered came up.  Connie mentioned that many liberal churches she's visited or been a part of over the years focused extensively on "doing good in the world" and this was translated into multitudes of community services such as soup kitchens or after school programs for troubled  youth.

While this is admirable work and many of these churches really do make a positive difference in people's lives, it does have some rather unfortunate consequences that, while not inevitable, are nevertheless common.  In particular, members are asked to volunteer considerable time and resources to supporting these causes, something regarded by many as a serious strain on their already busy lives.  More importantly, though, they are being asked to expend these resources largely helping people who are not part of their religious community.

Now, this is where things get really interesting.  Before I started studying religious groups I had a very cynical view of the charity work done by churches.  I felt that it was all done primarily as a means of recruiting new believers.  I thought that food, shelter and clothing was being denied to people unless they were willing to subject themselves at the very least to prayer and a sermon.  What I've come to appreciate in my field work, though, is that most churches don't seem to operate this way.  They usually open their doors to everyone and many assiduously avoid even the appearance that their community support is contingent upon acceptance of their world view.

This acknowledgment has softened my cynicism considerably, but it has also given it a new focus.  Namely, interviews with informants over the years have made it clear that while many in these liberal churches are happy to throw bread to the huddled masses outside their doors, they're rather uncomfortable inviting these people into the sanctuary for worship.  What appears on the surface to be an admirable statement of altruism is in effect a line drawn in the sand and those who try to transgress this boundary create a troubling sense of cognitive dissonance for members of the community.  They know all too well that the sign in front of the church says that all are welcome.  But in reality they aren't well prepared for the all that might come through their doors and they don't really want to be face to face with that all on a pleasant Sunday morning when they would rather catch up with friends and family over coffee and donuts.

But now we're back to the central problem, and it's really a problem of sustainability.  If we were to look at this through the lens of Elinor Ostrom's design principles, then these congregations are doing a good job of clearly delineating their boundaries, which, however hypocritical it may seem to be is nevertheless necessary to sustainably manage resources.  Yet they are using these resources not to help themselves but to help others.  The in group is bleeding itself for the sake of the out group.  It doesn't take evolutionary thinking or exposure to Lin Ostrom's scholarship to realize that this state of affairs is not sustainable in the long term except perhaps for those few congregations blessed with an excess of members who are existentially secure with lots of time to spare.

Contrast all of this with more conservative churches, particularly those of the Pentecostal persuasion.  Many of these churches also support soup kitchens and after school programs and the like.  However, they are far less squeamish about using these events to proselytize.  As such, they aren't drawing as distinct a boundary between "them" and "us" since their hope is that the "they" will become part of the "we."  Perhaps even more importantly, though, these churches typically offer a huge number of services to help their members as well as non members in the broader community.  On the one hand, it seems as though a Pentecostal congregation places extra burdens on its members with an expectation that they come to church three or four times a week.  However, congregants are typically getting valuable services for their trouble.  Rather than having to find a baby sitter to watch the kids while they go to teach remedial reading skills in an after school program, parents at an Assemblies of God will more likely drop their kids off at the church daycare while they attend seminars on financial planning, good parenting, or marriage counseling.  Is it any wonder, then, that they are often able to muster more resources and engage higher levels of commitment than many mainstream Protestant churches?  By seeing to the down to earth, practical needs of their members in ways that can help to relieve some of the stresses of modern life they concomitantly increase the ability of those same members to reach out and help those in the wider community, efforts that are unabashedly couched in terms of church growth.

It strikes me that this would be a relatively easy process to study and one we should add to our never diminishing project lists since it leads to a rather simple prediction.  Namely, the higher the proportion of in group vs. out group services a church offers, the better it should do in terms of growth and retention of members as well as its ability to engage volunteerism.  Conversely, the higher the proportion of out group vs. in group services a church offers, the worse it should do in all those same dimensions.


Friday, June 15, 2012

Architecture as a means of cultural canalization?

Part of being a student of David Sloan Wilson means meeting some very interesting characters.  Among some of the more interesting I've come across are Connie Barlow and Michael Dowd.  Connie is a science writer and an atheist who has been heavily involved with the Unitarian Universalist movement over the years.  Michael is a former Evangelical minister and author of Thank God for Evolution.  Together they serve as modern day itinerant preachers for an evolutionary, yet nevertheless highly spiritual, world view.  Or perhaps to put it in George Levine's terms, they advocate for a strongly enchanted evolutionary world view.  I met them once a few years ago when they gave a presentation at a local church, but didn't get the chance to talk with them in any depth.   Luckily, I had the opportunity yesterday when Connie and Michael stopped by the office for a visit to remedy that missed opportunity.

As part of the conversation yesterday, David and I explained our working conception of tight vs. loose groups and how these categories related to tolerance for within group variation.  This came on the heels of a discussion about David's desire to create an historical database of Binghamton area churches.  Connie put these two streams of conversation together to make a very interesting observation.  Namely, she said that congregations associated with old, beautiful church buildings tend to have members running the gamut from religious conservatives to agnostics.  As such, we might be inclined to think of them as generally "loose" congregations.  However, it is often the case that this variation remains largely buried beneath the surface, protected by a series of often unspoken taboos surrounding subjects that members tend to avoid talking about.

I find this observation fascinating on a number of different levels.  At the most basic, it represents a looseness in beliefs accompanied by a tightness in behaviors that we haven't accounted for or even thought about in any of our models.  More importantly, though, it brings together many different strands of my recent thinking that I feared were in danger of unraveling.  I have been so caught up in recent months with practical issues surrounding empirical work that I have had a growing anxiety that I have been losing sight of my broader theoretical questions about cultural robustness and evolvability.  It is important to have moments where you can step back, if even for a moment of clarity, to see how those endeavors are supporting one another.

I'm still mulling all of this over, but a starting point for synthesis comes from Roy Rappaport's Ritual and Religion in the Making of Humanity:

The simple fact of the continued existence of the 1,000-year-old cathedral, for instance, does more than speak of the endurance of a liturgical order and its relationship to a place and a group.  It demonstrates it.  Even a new cathedral build to a traditional plan demonstrates the endurance of the plan, and thus the order specifying it, and so does the manipulation of sacra which are either themselves ancient or which conform to ancient patterns. (location 2251)

Rappaport here is not discussing cultural robustness directly.  Rather, he is discussing the roles of material objects in ritual.  Nevertheless, I think he is hitting on something important to my own interests, something that accounts in part for Connie's observation.

Traditionally, churches have been built along certain plans that evoke the sense of endurance and timelessness that Rappaport illuminates here.  This becomes an important part of the church liturgy, a concrete (and very expensive) statement that the social order represented by the church is unchanging, that its correctness and morality are something outside of time.  This is fine as far as it goes.  However, the fact is that society does change over time and the "facts" deeply embedded within the architectural bones of the church at some point begin to become counterfactuals in the minds of those who have attached themselves in one form or another to that structure.

Yet, as Rappaport so convincingly argues, rituals, and the physical structures that support them, are so powerful in part because they remove ambiguity.  Either someone participates in a ritual or does not.  Either they become a man or woman by virtue of completing a rite of passage or they do not.  Either they have agreed to support a family in their war efforts through dancing around the fire or they have not.  But Connie's observation points to a flaw in Rappaport's argument.  Yes, an ostentatious cathedral enforces the idea that a church's rituals and, hence, ideals are eternal.  However, it does not necessarily communicate exactly what those ideals are.  If these are not made explicit in other ways then individuals are likely to define these idiosyncratically and a high degree of variation in beliefs is likely to accumulate.  That these differences in belief do not necessarily lead to changes in liturgical practices suggests that beautiful, old churches can act as components of cultural canalization.  They become physical means by which underlying variation is, if not suppressed, then at least subsumed in a way that allows the outward appearance of the church, its phenotype if you will, to remain unchanged.

Wednesday, June 6, 2012

Substrate Neutral Inheritance Systems

My preoccupation with cultural robustness and evolvability has naturally caused me to think frequently about the problem of cultural inheritance.  If we take a broad definition of culture to be non-genetic, non-epigenetic information that is socially transmitted, then culture becomes a Darwin machine like any other. For those unfamiliar with the term, a Darwin machine is any iterative process in which heritable variation is generated and subsequently undergoes some sort of selection.  The components necessary for creating a Darwin machine, then, are variation, selection and inheritance.

Note that this formulation is substrate neutral.  In other words, it does not depend on what the media of variation, selection and inheritance are.  Although the specific details will change, the same general logic applies whether we are talking about genetic systems, certain kinds of evolutionarily inspired computer algorithms or, presumably, culture.  This makes the notion of a Darwin machine potentially quite powerful in its ability to describe and understand many different kinds of systems from within a common framework.  Unfortunately, though, there remains much work to do in order to realize this potential.  In particular, to become more broadly applicable the individual components that make up Darwin machines must also be framed in substrate neutral terms.

To take but one of the necessary ingredients into consideration, how could inheritance systems be framed in substrate neutral terms?  To begin to imagine this I think it makes sense to start by considering the necessary components that make up the system we understand best, the genetic inheritance system.  So thoroughly studied has this system been that a central dogma has arisen around it that describes the flow of information within cells.  This flow begins with information storage in the form of DNA.  Almost every cell within a body contains a complete copy of all the genes necessary to build and maintain the organism.     However, not every gene is expressed at every moment.  Indeed, timing is critical for many cellular processes and so cells have evolved mechanisms to determine which genes should be turned on and off at specific times in response to environmental signals.  Once a gene is turned on, it is transcribed into an RNA intermediate which is, most often, translated into a protein product that performs some important function for the cell, be it structural, regulatory or metabolic.

At some level, carving this system up into essential components is a bit arbitrary.  Nevertheless, I think some general themes do emerge.  For instance, it seems an important component is some kind of information storage system.  Obviously, for inheritance to occur there must be some way of transmitting this information to new entities.  At the same time, there needs to be an information retrieval system and a crucial part of this information retrieval system would seem to be way of "reading" the environment to "know" what information is required and when it is needed.

Are these the minimal necessary components?  Would they be sufficient to establish an inheritance system?  Are all of them needed?  Are there other components missing from this list?  I would very much like to see more discussion along these lines and I welcome any insights others might have.

I recently had someone tell me that there was no need for new, substrate neutral terms.  He felt that genetic inheritance provided a sufficiently broad framework and that it could easily be expanded to accommodate other kinds of systems.  I think this is a mistake for at least two reasons.  First, I worry that using genetic terminology predisposes researchers to only look for the familiar.  While there are undoubtedly similarities in cultural and genetic inheritance systems, there are just as assuredly significant differences as well.  Foregrounding future work with genetically laden conceptual frameworks makes it likely that at least some of these differences could be completely overlooked.

Second, I believe that taking a step back to look at inheritance from a substrate neutral perspective produces new questions and opens space in which to explore them.  For instance, if it is true that an inheritance system needs some form of information storage then an obvious difference between genetic and cultural evolution is that the former contains information in a relatively concentrated from while the latter uses a distributed system.  This observation leads naturally to the question of how concentrated vs. distributed systems might respond differently to natural selection.  It similarly leads to questions about how information retrieval is achieved in a distributed system in a way that allows entities to respond adaptively to their environment.  I don't feel these same kinds of questions emerge as naturally when using analogical reasoning to expand a genetic framework.

Monday, May 28, 2012

Ultimate Sacred Postulates

I was finishing up Malley's How the Bible Works last night and came across this interesting idea, one that is congruent with some thoughts I had a few years back but never really followed up on:

In Rappaport's model, the most fundamental premises of a society are its "ultimate sacred postulates" (USPs).  USPs are distinguished from the other understandings present in a society in that USPs are nonempirical, beyond the reach of logical refutation, and regarded as unquestionable.  Examples of USPs given by Rappaport are the Shema of Judaism and the Shahada of Islam.  Such postulates have an important social function in that they define a community and thus serve as a kind of core around which the community can transform and adapt to circumstances while preserving its essential identity.  It is important for this function that they be neither empirically nor logically falsifiable, because this shelters them from every having to change.  Their nonempirical, often nearly tautologous nature makes them ideal foundations for community identity.  (pp. 137-138)

This passage brings together a number of strands of scholarship without referring to any of them.  For instance, it is resonant with my own interests in cultural robustness and evolvability.  Note in particular how an instance of robustness, the unchanging nature of USPs, is said here to form a core around which a community can adapt.  In other words, the presence of USPs allow a degree of evolvability by virtue of the fact that they can remain constant markers of group identity.  Presumably, if group identity were not so robust, then the social boundaries of that community might have to be renegotiated with every adaptive change, thus risking group cohesion at every twist and turn of a community's evolutionary trajectory.  The proximate mechanisms by which this robust trait is brought about is by placing USPs outside the realm of refutation, a very clever trick when you stop to think about it.

And, of course, this passage evokes, though likely unintentionally, Lin Ostrom's work.  Clear social boundaries are part of the very first design principle.  This naturally leads me to wonder if USPs might also accompany other design principles as well.  My work on religion and natural resource management doesn't currently touch on this question, but it wouldn't take much effort to launch a study of USPs and design principles from this project.  That isn't to say it wouldn't take a lot more work.  We'd basically have to code each instance we've found of religion playing a role in a design principle for whether a USP is evoked or not.  This might require more research into the specific beliefs involved than what we currently have in the database.  However, it might not if we could get by ignoring the requirement that USPs be "regarded as unquestionable" and instead focus exclusively on whether they are "beyond the reach of logical refutation."  For instance, I would be inclined to code the belief that ancestors are watching over a sacred grove as something beyond the reach of logical refutation.  This point could be argued, but it wouldn't be a bad first approximation, and one we could use our existing coding of case studies to address.

Needless to say, Rappaport has moved to the top of my reading list...

I was going to start a new blog entry for this last quotation from Malley, but it seems closely related to these ideas so I'll just continue here.  Malley makes the point that an important aspect of Evangelical Biblicism is the fact that the canonical texts are closed and well defined, making them clearly demarcated from other kinds of texts.  He then goes on to say:

This conventional boundary affords a different kind of flexibility.  By demarcating the boundary of scriptures very clearly, the content of the texts can be left unspecified.  So long as evangelicals can know what counts as a biblical text, they do not need to have a very elaborate knowledge of what is in those texts.  Their practice turns on establishing links between their ideas and some biblical text or other, and this can be done in ad hoc ways so long as one has some way of knowing what counts as a biblical text.  The closure of the canon affords openness in interpretation.  (pp. 150-151)

So once again we see an example in which robustness, in this case the rigidness of canonical boundaries, can lead to greater evolvability in the form of openness of interpretation.  Good stuff!

Wednesday, May 23, 2012

Caught Between Scylla and Charybdis

It's been many years since I've seen the names Scylla and Charybdis.  In fact, the last time I read those names was probably in middle school when I had something of an obsession for Greek mythology.  With so many years elapsed, I had to refer to Wikipedia just to be sure I remembered them correctly and, though the details had largely vanished from my mind, I did still retain the basic idea.  Scylla and Charybdis were two sea monsters situated on opposite sides of a narrow straight.  Sailors making a wide berth to avoid Scylla, a six headed beast, ran the risk of coming too close to Charybdis, a formerly beautiful daughter of Poseidon who became a hideous bladder that sucked in and spit out water in the ocean to form whirlpools.  Being caught between Scylla and Charybdis, then, is to be caught between a rock and a hard place, but with ghoulish monsters to make things more interesting.

So what brought these images back to my mind?  They were used as a metaphor in Brian Malley's How the Bible Works to describe the tension Evangelicals face when transmitting their interpretive tradition:

The interpretive tradition is perennially caught between the Scylla of interpretive freedom and the Charybdis of irrelevance:  to much hermeneutic freedom and the tradition disintegrates, loosing its epistemological appeal; too little interpretive freedom and the Bible becomes merely an irrelevant historical artifact, rather than the ever living word of God. (p. 124)

This is relevant not only to our collective work on tight vs. loose congregations but also to my own work on cultural robustness and evolvability.  On the latter point, I find Malley's observations particularly illuminating and worthy of further research at some point down the road.  According to him, the interpretive tradition received by lay people is relatively devoid of interpretive freedom.  People aren't really reading the Bible to search for new meaning.  Rather, they read the Bible in the search for relevance.  They do become skilled in finding Biblical passages that confirm beliefs they hold, but in terms of their personal reading of the Bible, they mostly seek to find ways in which what they are reading can speak to their lives at the moment.  When they find this kind of relevance, they perceive it to be God speaking to them through the intervening text.  Note that this is a very different relationship with a sacred text than what is common in, say, Jewish tradition in which each generation is encouraged to wrestle with the Torah and Talmud in order to create new meaning that speaks to an evolving world.

So where, then, is the source for new interpretations in Evangelical traditions?  How do they avoid the Charybdis of irrelevance?  Malley locates at least a partial answer to this question in Evangelical seminaries.  Ministers often undergo extensive training at institutions of higher education in which a true hermeneutic tradition is taught.  New generations of pastors, then, have the opportunity to read the sacred text anew and engage in a Biblical scholarship that can open up new possibilities.  Obviously, this is a relatively conservative process, constrained as it is by notions of what the previous generation of scholars, who are the current professors, deem acceptable deviance from the norms.  Nevertheless, it is a fertile ground for at least some innovation and this, then, after undergoing its own kinds of selection processes, can leak its way into the more general population of believers, who will generally accept it without much critical thought.  This dynamic strikes me as an excellent example of robustness and evolvability at work.

Wednesday, May 9, 2012

Mind = blown

I don't remember what specifically prompted me to order Brian Malley's How the Bible Works:  An Anthropological Study of Evangelical Biblicism, but it arrived late last week and I've spent most of today devouring it. However the book captured my attention, it has so far been well worth the read and I have no doubt but that I'll be quoting it in our Bible as Cultural Genotype manuscript.

Of all the insights it's given me though, the one that stands out most strongly in my mind after a solid day of reading came in the introduction. I'm still trying to wrap my mind around it and its implications so for now I'll simply quote a thought provoking paragraph (p. 8):

The presumption of textual meaning, it seems to me, is a specific case of the general principle proposed by Dan Sperber and Deirdre Wilson (1995), that although humans generally transmit only partial and ambiguous representations of the messages they intend to communicate, listeners' presumption of an intended message's relevance enables them to select, from among the possible interpretations, the one intended by the speaker.  On Sperber and Wilson's view, all communicative signals are partial and ambiguous representations of their intended messages.  The recipients of signals are therefore confronted with the task of sorting out which of the possible interpretations is intended by the speaker.  They are aided in this task by the speaker's implicit promise that the signal is as appropriate as possible for the intended message (Grice 1989).  Sperber and Wilson give a cognitive explication of this promise:  the speaker, in attracting the listener's attention and offering an utterance, implicitly guarantees that the informational value of the intended message is greater than the energetic cost of cognitively processing it.  The listener recognizes this implicit guarantee, and selects the first interpretation that meets this standard of relevance.  It may be that further interpretations could be explored with more cognitive effort, but once the promise of relevance is satisfied, interpretation stops.  (Of course, the guarantee of relevance may not be given in good faith, or a speaker may misjudge the conditions of relevance for the listener, or a number of other things might go wrong but in general, the principle of relevance guides the listener to the speaker's intended meaning.)  In ordinary conversations, then, interpretation is both initiated and guided by the expectation of relevant meaning.

In other words, "In a sense, the meaning arises only because it is presumed."  (p. 8)

Food for thought, presuming of course that all this really means something.

Monday, April 23, 2012

Two can play this game... :)

So here's a little radar diagram that I've done up to represent some of the things we discussed this afternoon. Specifically, it relates to the idea I had about mapping congregations in terms of their expressed levels of diversity on the horizontal axis and tolerance of diversity on the y-axis. If we further break diversity and corresponding tolerance down into beliefs, behaviours and demographics categories, we could arrange measures for specific faith communities as such:


If we could swap perceived for actual the above schematic, then I think we’d have an interesting handle on what it means to be a tighter faith community (i.e. a relatively small surface area - Church B in this example). The problem with this of course is that doing so would require a list of all the beliefs individuals are supposed to subscribe to and getting a sense of existing drift for each community. Not intractable, but certaintly not feasible for the moment. So we may be stuck with perceived. Actually, now that I think about it, having all three would be ideal - actual, perceived, tolerance. As it stands, “behavioural diversity” is a little up in the air… do we mean life behaviours or worship/religious behaviours? 

Thoughts? Specifically, is surface area a decent measure of tightness? For example, what if group C is really high on diversity, but low on corresponding tolerance measures, and group D is low on diversity measures but really high on corresponding tolerance measures. Both would have the same area but be manifestly different groups. Clearly some distinguishing power is lost. Are both congregations effectively equally Tight but for different reasons? I don't think so, as one would be open to increasing diversity while the other is not. Does this mean the polygon created by the Tolerance axes is the Tightness measure and the other half really constitutes a Disparity measure between "ideal" and "actual" or "perceived"?



Sunday, April 22, 2012

Rules as Genotype: Random Reflections

As much as I enjoyed the workshop last week on the topic of "rules as genotype," I've been increasingly disappointed that nothing was really accomplished by the participants there.  We had some amazing conversations, but we could never really get beyond various restatements of the metaphor.  In the end, I believe the only conclusions were either that the metaphor was still viable or that it had run its course.  No one, however, clearly articulated why they fell into one camp or the other and about the most useful comment was also the most obvious.  Namely, when you argue from metaphor, trying to map concepts from one domain to another, you're bound to be wrong in the details.

Aside from having too many different disciplines at the table to make much progress in two days, I think the workshop went off course primarily because no one wanted to get his or her hands dirty hammering out the messy details of vocabulary.  For instance, I don't recall anyone asking what a genotype was or what rules were or what aspects of a genotype rules were supposed to emulate.  Yet these are fundamental problems that have to be overcome if there's to be any hope of progress on this idea.

Thankfully, there a number of thinkers who are taking the idea of universal Darwinism seriously and who have done at least some of the basic groundwork.  I need to become far more familiar with this camp, but I believe Hodgson and Knudsen may have already answered this question in Darwin's Conjecture.  I don't want to try to summarize their entire argument here, or at least not now.  However, key to their argument is something they call a generative replicator.  For them, replicators require four conditions:


  1. Causal implication:  The source must be causally involved in the production of the copy, at least in the sense that, without the source, the particular copy would not be created.
  2. Similarity:  the replicated entity must be or contain a replicator.  The conditional generative mechanisms in the copy must be similar to those in the source.  Errors or mutations in these mechanisms must also be copied with some degree of fidelity.
  3. Information transfer:  During its creation, the copy must obtain the conditional generative mechanisms that make the copy similar to its source from that same source.
  4. Conditional generative mechanisms:  Generative replicators are material structures that embody construction mechanisms (or programs) that can be energized by input signals that contain information about a particular environment.  These mechanisms produce further instructions from a generative replicator to their related interactor that guide its development.  (pp. 122-123)
So, are rules a kind of generative replicator?  Before answering that, it's worth asking of genotypes are generative replicators.  According to Hodgson and Knudsen the answer is yes.  DNA cannot be replicated without the template, fulfilling the causal implication.  the replicated entity, the nascent strand of DNA, most certainly fulfills the similarity and information transfer requirements.  Moreover, the resulting daughter strands of DNA are capable of responding, through a variety of epigenetic mechanisms, to environmental inputs in order to guide development.  

If we can accept Hodgson and Knudsen's definitions, then it seems the question we should have been asking at the workshop was, really, are rules generative replicators?  Scanning the bibliography of Darwin's Conjecture, it looks as though Hodgson at least has already written a lot in this area that I should become more familiar with.  Unfortunately, the closest they come to discussing rules in the institutional sense is their exploration of judicial law as a major transition (Section 8.5 and assorted other places within the book).  For a variety of reasons I was unhappy with this particular discussion.  Perhaps the most glaring disagreement I had with them was their insistence that judicial law requires writing.  This simply flies in the face of historical fact, perhaps best exemplified in Icelandic law.  None of that, however, is particularly relevant to the concerns here.  

The authors argue that judicial law does constitute a generative replicator.  The causal implication requirement is a bit vague, but it seems to be met at some level either when laws are copied to new states (one form of replication) or when new laws are written which tend to rely on existing legislation.  It seems the argument here would be stronger if they included laws being passed from one generation to another, but I don't believe they consider this process in their formulation.  At any rate, these same processes, along with judicial review, which tends to clarify and refine laws, ensure that the similarity condition is met.  Undoubtedly, laws contain information so the copying of laws involves information transfer.  Conditional generation occurs because laws are typically invoked under specific circumstances and because they guide the development of the state institutions of which they are a part.

The hard work, then, seems to have already been done in answering the question of whether rules can be considered cultural genotypes.  It would be almost trivial to map Hodgson and Knudsen's argument onto Ostrom's formal conception of institutional rules.  For now I'd feel comfortable concluding that rules, like laws, could be considered conditional replicators.  A question that remains unanswered in my mind is what would be the cultural "phenotype" associated with rules.  In other words, what is the interactor that rules respond to?  An even bigger question, though, is so what?  If rules are generative replicators, then what are the implications for research or policy development?  In what ways might this formulation of rules provide new insights or help to organize existing knowledge?  These, too, were questions that didn't get addressed at the workshop and I think they are perhaps the most important questions of all.

Yet another concept map

It seems these are always hopelessly flawed.  Nevertheless, this map seems to capture most of what we've been talking about.  How useful it may be is another question entirely.



So, here I've partitioned the environment into different aspects, those that affect groups and those that affect individuals.  These, however, are not compartmentalized which is my way of attempting to show these are not always separate.  As I've been discussing, then, groups and individuals may have very different experiences within the environment and, as a result, may face different kinds of pressures.  The environment alone, however, is not the only source of influence/pressure/constraints/whatever.  Groups can also exert pressures on individuals and, of course, groups are affected by the traits of the individuals who comprise them.  All of these different influences work to produce outcomes.  Outcomes at the group level might be different from outcomes at the individual level.  Or they might not.  Perhaps I should have placed them in a box together the way I did for environmental influences?

I haven't quite unpacked this yet, but it may be in the outcomes that we find some traction with our conceptions of "alignment" between groups and individuals.

Does this do any useful conceptual work?  Again, I'm not entirely sure.  However, it does allow us to more methodically follow constraints and pressures (are these different?) to see how they might affect tightness or looseness.  For instance, let's imagine a harsh environment that offers little existential security for either groups or individuals.  This would limit the variation between groups operating within that environment and between individuals who are potential members of groups.   These should work together to create very tight groups.

Or what about an environment that is existentially secure for individuals but in which groups face existential insecurity by virtue, say, of fierce competition with other groups.  In this environment, groups should be far looser than in the previous scenario.  Nevertheless, they should be relatively tight in those particular traits that lead to differential success for the group.  For instance, let's suppose that successful groups within a given context are those with the greatest perceived entertainment value.  If groups can only survive by virtue of their entertainment value, then opinions about the relative importance of entertainment among group members should be tight even while opinions about other aspects of the group might be quite loose.  Clearly, I need to think of better examples but hopefully this gives an idea of what we're after.

One thing I do like about this map is that unlike some of my other recent formulations this provides space to consider the bottom up influence of individuals on the group and the top down influence of the group on individuals.  Aside from giving us a place to stick psychological variables like personal need for structure and social dominance orientation, it also gives us a way to consider historical trajectories.  For instance, if a tight group has survived several generations of individuals then it seems likely individuals raised within the group should have a higher need for structure or a higher social dominance orientation by virtue of their indoctrination over generations by the group.  Even if that group moves to a place where existential security at both the individual and group levels would lead us to predict greater looseness, it may take considerable time for the group to move in that direction due to to the bottom up influence of many tight individuals working in concert.

Okay, now I'm just rambling.  Enough!


Saturday, April 21, 2012

Selection

Tonight in an email exchange with Ian, the subject of selection came up.  Or perhaps more accurately, the problem of defining selection pressure came up.  Over the past couple of entries, I've been excited about thinking of group tightness and looseness as responses to differential selection pressures acting at the group and individual levels.  There is something intuitive about the idea that just "seems right."  As is so often the case, though, translating that gut intuition into something meaningful and practical is proving more difficult.

One stumbling block in this is that the entire scheme relies on understanding selection pressures that might act on either the group or the individuals comprising the group.  But what exactly do we mean by this?  How can we operationalize it?  How can we measure it?  My tack so far has been to come up with as many examples as I can of different groups falling into different categories of tightness and looseness and to think about the selection pressures at work.  While this has been seductive, I've started uncovering examples where the whole scheme seems to break down.  These have been instructive, though, inasmuch as they haven't been able to completely refute the scheme; they've left some room for the overarching idea to still wiggle free.  It's in this ambiguous space that I've come to appreciate where more precision is required.

I think one place to begin is to define what we mean by selection.  Without a firm conception of selection, any talk of selection pressure become rather silly.  I'd like to have a more exhaustive inventory of accepted definitions, but it's already past my bedtime so for now I'll just share the definition given by Hodgson and Knudsen in Darwin's Conjecture:

Selection in a complex population system involves an anterior set of entities that is somehow being transformed into a posterior set, where all members of the posterior set are sufficiently similar to some members of the anterior set, and where the resulting frequencies of posterior entities are correlated positively and causally with their fitness in the environmental context.  The transformation from the anterior to the posterior set is caused by the entities' interaction within a particular environment.  (pp. 241-242)

Interestingly, they differentiate between two different kinds of selection:  subset selection and successor selection:

Subset selection is defined as selection through one cycle of environmental interaction and elimination of entities in a population, structured so that the environmental interaction causes elimination to be differential, and where survival outcomes are correlated positively and causally with fitness in that environment.


Successor selection is defined as selection through one cycle of replication, variation, and environmental interaction, which leads to differential replication, novel entities, and a changed distribution of population properties that correlates positively and causally with the fitness of entities in that environment.  (p. 242)

Fitness plays a role in all of these definitions, so it's probably a good idea to pin what they mean by that down, too.  This turns out to be a bit thornier than you might expect:

In biology, fitness is most usefully defined as the propensity of a genotype to produce offspring (DeJong 1994).  Survival of the fittest is no longer a tautology:  it is possibly false.  The fitness of a replicator is the propensity to increase its frequency (relative to other replicators).  In the social domain, this definition of fitness translates into the propensity of a social replicator (such as a habit or a routine) with a particular feature to produce copies and increase the frequency of similar replicators in the population.  The fitness of an interactor is the propensity of its replicators to increase their frequency. (p. 238)


Here I sense some slippage between these concepts.  Much, I'm sure, to Ian's delight Hodgson and Knudssen define selection in terms of elimination of entities due to their interactions with the environment.  However, their notion of fitness seems to be more in line with conceptions of  selection for entities.  Perhaps that's neither here nor there, but it is curious to note all the same.

So what to make of these definitions?  At this point, I'm not entirely sure.  More than anything, I just wanted to get them out there for us to begin playing with.  However, some preliminary thoughts are that if we define selection in a similar way, then selection and existential security are in many ways interchangeable.  Selection pressure, which oddly isn't defined at all by Hodgson and Knudsen, would seem to be a property of the environment which affects how much variation can be present within a given population interacting within a particular environmental context.  If this is so, then it would seem to be even more directly related to notions of tightness and looseness than I first thought.  At the very least, it's not hard to see how I could come to the idea that selection pressures are key to understanding these phenomena.




Tuesday, April 17, 2012

Partitioning selection to understand tight and loose groups

A couple of days have passed since my initial epiphany regarding the tight/loose distinction.  Having come down from that emotional high, and being rather regrettably sober for the moment, I thought it might be a good idea to revisit my initial intuitions and to frame them a bit more formally.  

I begin with the acknowledgment of individuals.  To facilitate discussion, I will talk about these most naturally as single organisms but, in principle, I think it could be any entity with a given set of properties existing in the world.  I further acknowledge that individuals can come together to form groups composed of multiple individuals.  For the time being, I'm not going to fret too much about how that group is defined or how it's bounded, though that's clearly something that needs to be considered.  I should also point out that I'm not concerned with the fact that individuals can be thought of as collectives of individual entities. That simply moves the level of analysis to differing levels of complexity without affecting the broad theoretical framework I hope to develop.

I propose that, once a particular group is constituted, it becomes an entity in the world in its own right.  If this is so, then a group, just like an individual, can become subject to selection pressure.  As an aside and in a nod to Ian's theoretical work, my intuition tells me this will hold true regardless of whether we think of selection for or selection against.  However, I haven't come close to thinking through any of that so I'll leave it for now.

This brings us to a crucial point.  Namely, individuals who are members of groups are themselves still subject to natural selection.  This means that natural selection can act at all levels of organization.  This, I think, is obvious but somehow it's escaped our attention so far as we've tried to think our way through what environmental factors might be favorable to tight or loose groups.  Furthermore, I think this may be absolutely key.  To see why, consider that there is no requirement that the selective pressures at both levels or organization be at all closely aligned.  I expect that groups can evoke emergent properties that make them subject to pressures not necessarily felt by individuals.  Whether the converse is true, whether individuals can be subject to selection pressures not felt by the group they belong to, is a bit thornier so I'll set that aside for now.  At the same time, even though selection pressures at different levels need not be aligned, it's not unreasonable to imagine that they often are.

This is all still a bit sketchier than I'd like it to be, but I think it sets up some interesting predictions.  For instance, individual variation in any particular trait should be inversely proportional to selective pressure working on that trait.  If there is strong selection for a suite of traits, then variation in those traits should be relatively low.  If selection is weak, then variation should be greater.  (And here I suppose the selection for vs. selection against changes the syntax a bit.  Whether it changes things more substantively is an open question.)

If all this holds true, then we can start asking interesting questions.  The simplest is, what happens when selection is weak at both the individual and group level?  The prediction in this case is that such a circumstance would allow high degrees of variation at the individual and group level.  Many different kinds of groups should be able to thrive in such an environment and the variation of individuals within each groups should also be high.  All groups would likely become loose groups, with high levels of variation.  

What if selection pressure at the group level is high, but selection at the individual level is low?  Under these conditions, we'd expect less variation in the kinds of groups that exist in an appropriate level of analysis, or perhaps more precisely, we'd expect groups existing within that context to exhibit less variation in those traits that are adaptive to the pressures being exerted.  On the other hand, the traits exhibited by individuals within each group could show considerable variation as long as the composition of individuals reliably evoked the group level adaptive traits needed for the group to survive.  Given that the group is under strong pressure in this scenario, we might expect there to be some core traits that are in some sense inviolable; without them, the group could not survive.  Again, groups facing this kind of differential selection pressure at the group and individual level should be loose.

Tight groups, then, should emerge any time that selection pressure at the individual and group levels are relatively high.  One thing I need to think more deeply about is what happens when selection pressures at the group level are weak relative to selection pressures at the individual level.  My sense right now is that this would not affect tightness so much as it would the variation in the kinds of groups that might emerge within the environment, but I'm not sure that really follows.  

However that may turn out, it seems to me that this basic framework, sketchy as it is, does at the very least accounts for many of our existing observations.  For instance, fundamentalism, which neatly fits our tight category, is associated with existential insecurity.  In other words, when individuals are living on the edge of existence, when they are experiencing strong selection pressures, they form tight groups. In the most extreme circumstances, the survival of the group and the survival of the individuals within the group are very closely aligned in that the traits that are individually adaptive within that context are likely very similar to group level traits that are similarly adaptive.  An interesting prediction from this that I don't think I've heard before is that because selection pressure at the group level is also high, you would expect to see a reduced variety of groups operating within that environment since relatively few kinds of groups will be adaptive.

In times of existential security, by contrast, selection pressures at the level of the individual are greatly reduced.  This should lead to a greater variety of groups and to a greater tolerance of diversity within those groups.  If these groups end up in competition with one another for some resource, then the variety of groups should diminish in response to the selection pressures, but tolerance within each group for diversity should remain relatively high as long as the diversity does not affect those group level traits that are adaptive.  This could account for why some of the loosest churches we've come across seem to have members who are middle class and uncharacteristically high levels of education.  This lines up neatly with some of the strict/lax literature, though it reaches the same predictions from a very different direction.  It also accounts for why many of those churches are struggling to survive.  Although in many cases they seem oblivious to the fact, they are in fierce competition, not only with other religious groups but, as David is so fond of saying lately, also with secular alternatives.  That they are failing to grow or even hold steady likely reflects that they have not found, despite (or perhaps because of) all their internal variation they have not hit upon the "trick" of surviving in the current social context.

Whew!  I could probably go on, but I doubt anyone has made it this far.  Hell, I don't even have the energy left to go back and proofread what I just wrote.  Nevertheless, I'm glad to have laid all this out and I welcome feedback.  I'm not quite there yet, but I think I'm getting closer and I think we're getting close to being able to make some novel predictions that we can test.