So...it's not genetic after all! (but who's listening?)

Is it time to predict the gradual out-cycling of a focus on genetic causation and a return of environmental causation, in our mainstream scientific dialog (and funding-pot)?  Such a recycling is bound to happen--even if, say, genetics' claims were correct.  Why?  Because the new generation has to have something to show they're smarter than their elders, and because the abuse of genetic determinism by society is a nearly inevitable consequence of the fervid love-affair we're now having with genomics and its glittering technology.  But maybe there's another reason:  maybe genetics really has been oversold!  Is it possible?

Bees and societal (in)determination
Honey bee harvesting is a social phenomenon and experiments by various authors have found that only a fraction (in some studies, 20%) of the workers actually do most of the work.  But a recent controlled study reported in the journal Animal Behavior by Tenczar et al (vol. 95, pp41-48, 2014, but paywalled) found that if those 'busy-bees' are removed, others step in to fill the work gap.  The gist of the evidence seems to be that among the gatherer work force (and presumably other castes as well, though that's not reported), there is a spectrum of contribution and it's condition or context-dependent.  As the paper says:

These bees resembled ‘elite workers’ reported in a number of other species. However, our results also show that honeybee foraging activity level is flexibly adjusted during a bee's lifetime, suggesting that in honeybees, elitism does not involve a distinct subcaste of foragers but rather stems from an extreme of a range of individual activity levels that are continuously adjusted and may be influenced by environmental cues.  . . . these results support the view that individual workers continuously adjust their activity level to ensure that the colony's nutritional needs are being adequately and efficiently met, and that the net activity of the whole foraging population is likely to be one of the factors that influences this decision. 

The authors discuss the fact that these patterns have not been studied, with varying levels of rigor, in many species of social insects.  While it is not clear that genetic differences are never partly responsible, the evidence is that social roles are not rigidly pre-programmed.  This study was presented by the NYTimes with a captivating video from the authors, but while that was nice and led us to the research story itself, the Times characterized this as a system allowing upward social mobility.  That's a bit pandering to middle-class readership, and didn't really critique this work in the context of today's prevailing genetic-deterministic viewpoint. However, the idea of context-dependent roles, based on the needs and opportunities in society at large, is noteworthy and of course is something that also happens in humans.

Honeybee; Wikimedia Commons

This of course raises the question of how the bees perceive the needs or different roles, or if the role pattern is a spectrum of activity of each bee, then how does it know when and what to do.  This would relate to the bees' brains' ability to digest quite complex information and make decisions, something very interesting to try to understand, and something we wrote about here not long ago.

Intelligence
A new paper in PNAS reports the results of a large study of the genetics of IQ.  Essentially, they found three genes with very small effect and unknown functional association with cognition.  Indeed, one of the genes may not even be a gene. To sort this all out, of course, they say they would need a sample of a million people.  One of the authors faced with this mountain of chaff is quoted this way in the story:

Benjamin says that he and his colleagues knew from the outset that their efforts might come up empty handed. But the discovery that traits such as intelligence are influenced by many genes, each having a very small effect, should help to guide future studies and also temper expectations of what they will deliver. “We haven’t found nothing,” he says.

Nice try!  But the truth is that that is just what they have found: nothing.  Or, at least, nothing new, that is, no thing.  We knew very well that this was the most likely sort of finding.  We have countless precedents, including the results of countless earlier searches for genes for intelligence (and, for that matter, similar findings for most psychological/behavioral traits).  Like other traits from normal ones like stature and IQ, to body weight and major diseases of all sorts, we find polygenic control--countless contributing genetic factors with individually minimal effect. This even though usually the heritability of the trait is substantial, meaning that variation in genes together accounts for a non-trivial fraction of the overall variation in the trait (the environment and other factors contribute the rest, usually around 60-70%).  

But heritability is a persistently subtle and misunderstood (or ignored) measure. Even with nontrivial overall heritability, the aggregate nature of the measure means we cannot say in any given individual whether his/her IQ is based on this or that particular genes, or is some specifiable percent due to genes (that is itself difficult to make sense of when referring to an individual).  And heritability is often measured after taking out, or controlling for the major real causal factors, such as age and sex.  Arguing for a sample for a million, if allowed and funded, is a huge fool's errand and a corrupt way to spend money (because it's mainly to keep professors off the street of unemployment).

Yet the issues in these cases are subtle, because we also know of many different individual genes that, when seriously mutated, cause direct, major, usually congenital damage to traits like intelligence.  Yet few if any of these genes show up in these mega-mapping studies.  It is this sort of landscape of elusive complexity that we need to address, rather than just building expensive Big Data resources that will largely be obsolete before the DNA sequence is even analyzed, based on the daydream that we are not, knowingly, chasing rainbows.

The primary question one thinks to ask is whether 'intelligence' is a biologically meaningful trait.  If not, even if it can be measured and be affected by genes, it isn't really an 'it' and one can't be surprised that no strong genetic influences are found even if the measure is stable and heritable.  Asking about the genetic basis of intelligence under such circumstances is not asking a well-posed question.

Baby stories
The other day we posted about the recent Science issue on non-genetic influences on parenting,  environmental effects on traits and how long-term and subtle they can be, and how they are not Genetic in the sense of the G-rush we are currently experiencing.  The stories are many and diverse and tell the same tale.  

Here the fascinating question is how the various environmental factors could influence a fetus in factor-specific manners that even relate to the factor itself (e.g., maternal diet affecting the future baby's obesity level, or the effect of the mother eating garlic or being exposed to odors on taste preference or specific odor-related behavior in the child).  To answer such questions we have to know more than just about a gene or two.

So, why aren't these findings grabbing headlines?
The bee story made the front-page of the NYTimes, but mainly because of the video and not because it is a counter to the strong genomic hard-wiring ethos so often promoted by scientists these days.  Likewise, the baby influences made the cover of Science, but we didn't see a Hot-News blare announcing that genetics isn't, after all, everything.  And of course the IQ story didn't make that clear either, given that the author said he wanted studies of a million to find the real genetic causes of IQ.  And, determinists say this isn't going to change their mind about the genetics of intelligence, because it's definitely genetic.  

Will we, or when will we, see people begin to back off their claims of strong genetic determinism, and begin addressing the really hard questions concerning how complex genomes interact with complex environments to produce what we are clearly observing?  In my opinion, these questions cannot be addressed from a genetic, or from an environmental, or from a simple Gene + Environment point of view.

Are bees intelligent?

The other day, Ken and I had coffee with a couple of philosophers who spend their time thinking about philosophy of the mind.  What is consciousness?  Do non-human organisms have consciousness?  What is intelligence?  How do we make decisions?  What about ants?  These are hard questions to answer, perhaps even unanswerable, but they are fascinating to think about.

Our meeting was occasioned by the recent paper in PNAS about the mental map of bees ("Way-finding in displaced clock-shifted bees proves bees use a cognitive map", Cheeseman et al.).  Cognitive maps are mental representations of physical places, which mammals use to navigate their surroundings.  Insects clearly have ways to do the same; whether or not they do it with cognitive maps is the question.

Honeybee: Wikipedia

The "computational theory of mind" is the predominant theory of how mammals think -- the brain is posited to be an information processing system, and thinking is the brain computing, or processing information (though, whether this is 'truth' or primarily a reflection of the computer age isn't clear, at least to us).  In vertebrates some at least of this takes place in the section called the hippocampus, or in non-vertebrates in some neurological  homologs.  But, what do insects do?  

Previous work has shown that captured insects, once released, often fly off in the compass direction in which they were headed when they were caught, even if they were moved during capture and the direction is no longer appropriate.  But, they then can correct themselves, and then have no problem locating their hives. That indicates that they've got some kind of an "integrated metric map" of their environment.

Some theories have held that they mark the location of the sun relative to the direction they take and then later calculate 'home' based on a computation of time and the motion of the sun.  This by itself would be a lot of sophisticated computing, or thinking....and why not 'intelligence'?

Cheeseman et al. asked whether instead what they are relying on is a series of snapshots of their environment, which enables them to recognize different landmarks, one after the other as they come into view, rather than a completely integrated mental map.  They experimented with anesthetizing bees and shifting their sense of time, so that they couldn't rely on the sun to get them home.  It took some flying for the bees to recognize that they were off-course, but they always were able to re-orient themselves and get back to the hive.

Cheeseman et al. conclude that that because bees don't rely entirely on a sun-compass for their sense of direction, they must have the apian equivalent of a cognitive map.  That is, they collect relevant spatial information from the environment with which they navigate, and use it to make decisions about how to get where they are going. That is, they take and file away snapshots; remember that insect eyes are complex, including two compound eyes and in most species three forehead-located small, simpler ocelli so this is synthesizing a many-camera pixellation and differently sensitive integration of the light-world. Then, they use a sequence of these frames, later, from a different position from that at which the photos were taken so not all landmarks might even be visible, and at a different time, which can affect shadows, colors, and so on.  Then, tiling these lined up in reverse order in mirror left-right flipped order somehow, and adjusting their angles of perspective and so on, also perhaps sound, wind direction, and even perhaps monitoring the olfactory trail (also in reverse relative position) like Hansel and Gretel's bread crumbs, they head home for dinner.

Two big compound eyes, and 3 simpler central ocelli. From http://169.237.77.3/news/valleycarpenterbees.html

To us, this is a remarkable feat for their small brains!  For some of us, even with a human brain, finding one's way home without a GPS is no easy task, and deserves a nice cold drink when done successfully.  However, the philosophers we were chatting about this with did not think what Cheeseman et al. believe they discovered about bees should be called a cognitive map because, and we think we've got this right, they haven't got a mental image of the entire lay of the land.  Instead it's as though they are connecting the dots; they recognize landmarks and go from one mental snapshot with a familiar landmark to the next. So what kind of 'intelligence' this is becomes a definitional question perhaps.  Call it mechanical or whatever you want, we would call this 'intelligent' behavior.

We don't know enough about philosophy (or the biology) of the mind to know how significantly these two models differ, or whether 'consciousness' is subtly underlying how these judgments about cognition are made, but in any case, that's not what interested us about the bee story.  What is the experience of being a bee?  Whichever kind of imaging and processing they do to navigate, how do they turn the locational information into action?  It's one thing to know that your hive is east (or the apian equivalent) of the pine tree, but getting there requires "knowing" that after you've collected the nectar, you then want to bring it home, and that means you have to find your way there.  Your mental map, whatever it consists of, must be made operational.  How does that happen, in a brain the size of a bee's? Or an ant's?




Or bird brains?  Crows, corvids, are considered among the smartest of birds.  Their problem solving skills have been documented by a number of researchers, but crows have fascinated many non-scientists as well, including our son, who sent this observation from Lake Thun in Switzerland.

Crow found a little paper cup with some dried out dregs of leftover ketchup in the bottom. This is the sort of little paper condiment cup that would come with some french fries. We watched the crow try a couple of times to scrape some ketchup out with his beak, holding the cup down with his foot. It apparently wasn't working enough to his satisfaction, so he flew with the cup to the edge of the water (we were at the lake). He wanted to get the ketchup wet to "hydrate" it, to make it easier to scoop out. That was impressive enough, but what he did next was even more. There were little waves lapping on the "shore" (this was actually in a harbour and the shore was concrete) and each time threatening to carry away his cup. So he picked up the cup and carried it along up and down the shore until he found a little crevasse in the concrete that he could secure the cup, and let the water wash over it without taking it away. Clever.

If that's not intelligence, it's hard to know what it is, then.

One view of intelligence is that it's what's measured by IQ tests.  Or, at least, what humans think 'thinking' is all about.  But this is perhaps a very parochial view.  We tend to dismiss the kind of intricate brainwork that is required by nonverbal activities, or by athletes, or artists, or artisans.  We tend to equate intelligence with verbal kinds of skills measured on tests devised by the literate segments of society who are using the results to screen for various kinds of western-culture activities, suitability for school, and the like. There's no reason to suggest that those aspects of brainware are not relevant to society, but it is our culturally chosen sort of definition.

Philosophers and perhaps most psychologists might not want to credit the crow with 'intelligence', or they may use the word but exclude concepts of perceptual consciousness--though whether there are adequate grounds for that that are not entirely based on our own experience as the defining one, isn't clear (to us, at least).  In any case, wiring and behavior are empirically observable, but experience much less so, and consciousness as a component of brain activity, and perhaps of intelligence, remains elusive because it's a subjective experience while science is a method for exploring the empirical, and in that sense objective world.

If bees and, indeed, very tiny insects can navigate around searching the environment, having ideas about 'home', finding mates, recognizing food and dangers, and they can do it with thousands rather than billions of neurons, at present we haven't enough understanding of what 'thinking' is, much less 'intelligence', to know what goes through a bee's or a crow's mind when they're exploring their world....

Solving colony collapse disorder probably can't be just better bee husbandry

The problem of 'emerging infectious diseases' (EID) is well-recognized in humans and other vertebrates but less so among invertebrates.  Colony collapse disorder (CCD) is an ongoing and serious problem among honeybees that are used to pollinate food crops, but a new study published in Nature ("Disease associations between honeybees and bumblebees as a threat to wild pollinators", Fürst et al.) reports that whatever is killing managed pollinators is spreading to wild bumblebees and killing them too.  Indeed, wild bumblebee populations are in decline around the world.

Wild and managed bees already share some diseases, including deformed wing virus (DWV) and infestation with the fungal parasite Nosema ceranae.  Varroa mites seem to be among the causes of CCD, but they are not being found in wild bees.  Fürst et al. suggest that, as with vertebrates in which 'spillover' from domesticated animals to wild sympatric species, wild bees readily become infected with diseases that managed bees carry because they visit the same flowers.  Whether wild bees are as vulnerable as honeybees have been to the causes of CCD is yet to be seen.  

Source: BBC

Fürst et al. tested the infectivity of several diseases found in honeybees, DWV and Nosema ceranae, by inoculating bumblebees with the virus and infecting them with the fungus.  They found that these infections are indeed devastating to bumblebees, infected wild bees had non-viable offspring and shorter lifespans than uninfected bees.  

They then surveyed bumblebees throughout the UK and found evidence of active infection by both mites and DWV, although currently at lower levels than among honeybees -- 11% of bumblebees and 35% of honeybees had DWV, and 7 and 11% respectively had the fungus.  

They further found that prevalence of these infections was not uniform among their sampled wild bees but that it was correlated with prevalence in nearby honeybees. They further tested the strain of infection among wild and managed bees and determined that they shared the same strains. While they couldn't confirm the direction of infection, they suggest that it's likely to be honeybees to bumblebees since prevalence of DWV and fungal infection is higher in honeybees.  

The global trade in honeybees and the worldwide prevalence of CCD mean, to Fürst et al., that beekeepers need ways to reduce infection rates in managed bees, both for the health of these bees as well as for the health of wild bees.  But, as they point out, 'reducing the pathogen burden is not easy.'  They suggest that beekeepers should learn from experience with infection control in vertebrates.

Lessons learned from vertebrates highlight the need for increased pathogen control in managed bee species to maintain wild pollinators, as declines in native pollinators may be caused by interspecies pathogen transmission originating from managed pollinators.

A piece on the BBC website on Thursday includes this quote:

Dr David Aston, president of the British Beekeepers Association (BBKA), said: "By employing good husbandry practices, beekeepers can take steps to reduce the impact of pests and diseases on honeybee colonies using biotechnical controls and practices such as apiary hygiene, regular brood comb changes, ensuring the colonies are strong and well-nourished and the use of authorised treatments."

In other words, good husbandry can reduce the disease load on managed bees, and thus on wild bees, and knowing specific causes of CCD isn't as important as simple hygiene.  This may be true as far as it goes, but if pesticides and herbicides are part of what seems to be a complex chain of causation this problem can't be solved from hive to hive, but instead controlling use of toxic chemicals must be part of the solution.