A recent article about research supporting a neurological (= biological) basis for altruism panders to the alarmist view that behavior with an identifiable biological basis precludes personal responsibility, and could throw our criminal justice system into an uproar.

The first statement that shows an ignorance of sociobiology and evolution:

The results -- many of them published just in recent months -- are showing, unexpectedly, that many aspects of morality appear to be hard-wired in the brain, most likely the result of evolutionary processes that began in other species.

Why is this unexpected? In social animals, such a biological basis for morality would absolutely be expected. This is because morality governs social interactions, so animals who have evolved in the context of sociality have a biological need for it. Altruism is related to empathy, without which we cannot interact socially because we need a mechanism for assessing what another person is thinking or feeling. Those without empathy, such as autistics, are lost in the maze of unspoken rules that govern interpersonal interactions. Altruism is a way of acting on empathic information.

...some wonder whether the very idea of morality is somehow degraded if it turns out to be just another evolutionary tool that nature uses to help species survive and propagate.

The idea that "morality is somehow degraded" because it has a biological basis really has no logic to it, but it is typical of those who confuse morality with religion. Perhaps the idea is analogous to someone we like doing something nice versus someone we do not like doing it. In the latter case we assume insidious motives because we do not believe the person is truly being altruistic. But the mistake there is that there is no such thing as pure altruism, as research shows. Either altruistic acts cause us to receive tangible benefits, such as increased standing in a community, or if anonymous, provide us with pleasure (Moll et al., 2006).

Of course morality and altruism are complex neurologically because human social interactions are complex. But a biological explanation for moral behavior does not indicate a lack of need of philosophers or even religious thinkers who study moral behavior such as altruism. Humans are faced with ethical decisions nearly every day, and it is not always clear what is the altruistic way to respond, even if that is our goal. That is why religious advisors, analysts, and advice columnists are not automatically out of a job just because automatic brain function reveals our options. Our brains often do not make obvious the decisive course of action, that is, the course of action having the most positive or least negative social consequences, in the balance. Social consequences are a real biological phenomenon, because decisions affecting an individual's social standing often affect that of an entire family, which shares genes.

For example, there is the potential problem of revealing or not revealing a friend's indiscretions, such as an extramarital affair. In the short term, revealing the truth might be bad for the social group, as bonds are broken. But in the long term, the earlier such a truth is revealed, the quicker wounds may heal and the social group rebuilt. Such a decision is necessarily affected by social norms of the community, which are of course extremely variable among societies.

The article points out that "a number of experiments such as the one by Grafman have shown that emotions are central to moral thinking." Of course this is true. Grafman and his colleagues (Moll et al., 2005) make it clear that moral reasoning is a complex process that uses both reasoning and emotional centers of the brain - there is no one specific brain structure that dictates morality, but rather a series of structures that must interact in a complex way to produce a moral decision. The role of emotion is understandable because a major purpose of emotion is social navigation; for example, laughter is a way of making a social connection with another person. Solitary-living animals have no need for emotions such as love, anger, envy, pride, etc., because feeling these or acting on these invariably involves the establishment, maintenance, or alteration of a social relationship.

While several brain structures interact to produce moral reasoning, those involved can be identified specifically because specific brain damage has predictive effects on moral behavior (Moll et al., 2005). For example, damage to the prefrontal cortex at an early age prevents normal development of moral reasoning. Such people often have short-term, self-centered responses to moral dilemmas, because they have no sense of the social consequences of their actions. A different region of the cortex, the superior temporal sulcus, is required as well because it is a center of social perception, i.e. empathy, which is also required for normal moral reasoning. The limbic system, a center of basic emotional drives, also affects morality because behavior such as aggression is controlled by this area, and can become uninhibited when parts of the limbic system become damaged. Functional MRI studies also have indicated activity in the orbitofrontal cortex (behind the eyes), the anterior temporal lobes, the insula, and the anterior cingulate cortex in people processing moral dilemmas posed to them.

The claim that these discoveries mean that "society has to rethink how it judges immoral people" (according to Adrian Raine, a USC neuroscientist) is absurd. There is a minimum standard of behavior that is acceptable in a society, and this minimum exists whether or not you are psychopathic (= brain damaged in a way that impairs interpersonal interactions due to lack of empathy). If some people are physically unable to make correct social decisions, it does not mean we must treat them as equals. Serial killers are psychopaths, and whether their brain damage is physical or developmental, they cannot be allowed to move freely in society because they have no internal constraints against killing. We lock them up so that they cannot damage society further. Most people would agree that a similar situation holds for pedophiles - there seems to be increasing evidence that most are incapable of being "rehabilitated," which is not surprising; their psychopathy is likely due to brain damage - which again can be physical or developmental - that cannot be repaired. Damaged people must be isolated from society because the structure of society must be protected for the sake of the non-damaged majority.

J. Grafman says, "Some of the questions that are important are not just of intellectual interest, but challenging and frightening to the ways we ground our lives. We need to step very carefully." Not at all. This information is simple and reasonable when understood in terms of maintaining a functional society.

An interesting moral phenomenon in humans involves the altruism of helping someone near and dear to you versus helping people in distant countries that you will never visit. The neuroscientist/philosopher Joshua Greene, interviewed in the article, gets the implications of this wrong:

"We evolved in a world where people in trouble right in front of you existed, so our emotions were tuned to them, whereas we didn't face the other kind of situation," Greene said. "It is comforting to think your moral intuitions are reliable and you can trust them. But if my analysis is right, your intuitions are not trustworthy. Once you realize why you have the intuitions you have, it puts a burden on you" to think about morality differently.

Yes, we evolved in a non-global world, and our knowledge of the plights of people around the world sets humans apart from other social animals. But that is not the point. What matters is that any type of altruism affects one's standing either in society, or to oneself. Our higher reasoning ability convinces us that faraway starving children are as important as the starving children next door - even as our emotions tell us otherwise - but this does not make our intuitions untrustworthy, it just adds potential complexity to the moral decisions we make. If one is a member of a church, for example, where such generous behavior is valued, it increases or maintains one's social standing to give to the needy in faraway places, it makes sense to do it. For many people, "charity begins at home" is an acceptable societal standard, and thus there is no burden to think about morality differently. Undamaged brains can still rely on their moral intuitions, and navigate their social world successfully.

Of course the different details of morality across cultures require us to be flexible in their moral reasoning. The social brain must adapt to local social conditions to successfully reproduce. This creates difficulties in a globalized world in which we not only are aware of the different moral values in different societies, but people from those different societies interact daily, not only in person, but probably more important these days, over the internet. To use an extreme example, people from societies that support individual rights for women have worked hard to stop what to us are sickening cultural practices such as female genital mutilation. Any Western woman is horrified by the practice with good reason - it not only is such an extreme example of oppression of women by men, which goes against our stated values (values that were hard won and still being fought for even in our "enlightened" society), but the long term health consequences are often dire. Yet efforts to eliminate the practice are often derailed by the women of those cultures themselves, because if they do not accept the ritual mutilation, they will be rejected by their society (and will not reproduce successfully there). It is nearly impossible to end such traditions by force. The values rejecting them must be inculcated in enough of the local population to the point where it becomes socially acceptable not to undergo the mutilation.

A similar example closer to home is the explanation of why most battered wives return to their husbands over and over again, contrary, it seems, to all reason. But in the cultures (and subcultures) in which wife-beating is common, breaking the cycle is so difficult because if a woman leaves her husband she often must give up her entire social group as well (and she often cannot fathom that it would be possible to become part of another social group, simple as that may seem in the abstract). Going it alone under such circumstances is contrary to our very nature as social beings.

It is completely natural for everyone to believe that their society's cultural norms are superior to everyone else's, because they know from experience that following those cultural norms make them successful. Of course though, if the same behavior is transferred to a society with different cultural norms, the result can be disaster. It is this naive sense of superiority (also held by most religious groups) that creates solutionless predicaments such as the current one in Iraq.

References

Moll, J., Krueger, F., Zahn, R., Pardini, M., de Oliveira-Souzat, R. & Grafman, J. (2006) Human fronto-mesolimbic networks guide decisions about charitable donation. Proceedings of the National Academy of Sciences of the United States of America, 103, 15623-15628.

Moll, J., Zahn, R., de Oliveira-Souza, R., Krueger, F. & Grafman, J. (2005) The neural basis of human moral cognition. Nature Reviews Neuroscience, 6, 799-809.

Labels: behavior, brain, empathy, humans, morality, sociality

Carnival of the Godless is up at Letters from a Broad. Atheists unite.

Labels: carnivals

The pipevine swallowtail is Battus philenor. In the U.S., it occurs roughly in the southern half of the country, east to west.
The caterpillars of B. philenor (below) feed exclusively on plants in the genus Aristolochia (pipevine). These plants are loaded with toxic compounds called aristolochic acids, which would kill, and thus deter, most herbivores. The pipevine swallowtail, however, is not harmed by aristolochic acids, and instead it sequesters them in its own body to use as a defense against predators. These butterflies are a classic example of aposematism, which means they advertise the fact that they taste bad to predators.
If an insect is black, red, yellow, orange, or any combination of those colors, it is likely to be distasteful. If an insect is green or brown and seems to blend into foliage, it likely tastes good to potential predators, and because of that it is hiding. Aposematic insects do not want to hide, they want to make it clear to the predators out there that they are no good to eat. This is because they are relying on learning by those predators (in the case of butterflies, often birds) learning to associate those colors with bad food. Another better known distasteful butterfly is the monarch, which feeds on milkweed, another plant with nasty chemicals.

Some butterflies which have aposematic coloring do not sequester nasty chemicals. Instead, they use a strategy of mimicry, and rely on the likelihood that predators will mistake them for bad food and avoid them as well. This of course only works if most of the aposematic butterflies do actually taste bad, because if a bird eats a black butterfly and it tastes good, it will not learn to avoid black butterflies, but to eat them. So generally in a population there is a stable balance of truly distasteful butterflies and mimics.
The caterpillars of B. philenor can either be black or red, and this is entirely due to the temperature at which they develop (Nice and Fordyce, 2006). When the temperature is over 30°C, A black caterpillar will overheat, so they become red instead, which keeps them cooler (black absorbs sunlight, and thus heat, much more readily than red). Interestingly, aposematism in B. philenor caterpillars seems to serve a dual function: in addition to deterring predators, the contrasting black or red color also deters a B. philenor adult female from laying more eggs on the same plant already occupied by larvae of the same species (Papaj and Newsom, 2005). This ensures that her offspring will have adequate food left for development.

Adult females lay their eggs preferentially on young foliage. This is probably because younger leaves are more tender and easy to eat by early stage caterpillars. Females determine the suitability of the foliage via chemical receptors (taste buds) on their feet. I established this in an unpublished study in which I stimulated oviposition by females on filter paper using organic extracts of young vs. old Aristolochia foliage (above); they much preferred to oviposit on extracts from young foliage. High pressure liquid chromatographic analysis revealed higher levels of several sugar alcohols in the younger foliage, so the butterflies may use that information to choose oviposition sites. At the time, however, we were unable to measure levels of aristolochic acids in young vs. old foliage, so that may also be a cue instead of or in addition to sugar alcohol levels.

These butterflies can be reared in the laboratory, but not easily. Getting butterflies to mate in a lab is challenging, but B. philenor was often quite accommodating. One could manipulate the genitalia of a male and female into contact, and sometimes get them to hold on and complete the mating (and thus get fertilized eggs in the female). Interestingly, what mattered in lab mating success often was the individual male - certain males could not be induced to mate, while with others we had success with several females.

These insects have been of interest to scientists not only because of their chemical relationship with their host plant, but because of their behavior as well. Many people assume that insects behave only according to instinct, but in fact many species have shown quite good learning ability. Parasitic wasps are often studied for their odor and sometimes visual learning skills, and butterflies as well are good learners. Mainly visual cues, e.g. color and shape, have been shown to be learned by B. philenor. For example, in parts of their range there are multiple species of Aristolochia upon which they feed, and females learn the leaf shape of the dominant species (Papaj 1986). This saves time for females searching for host plants, because ovipositing (egg laying) females can visually scan for potential host plants, and then test leaves of the correct shape for the compounds in Aristolochia, after which they confirm or reject it as a host plant.

A female B. philenor can also simultaneously learn one color associated with egg laying, and another color associated with nectar sources for food (Weiss and Papaj 2003). Similar ability has been found in some parasitic wasps. It actually should not be surprising that insects are good at learning. If your brain is tiny, you have fewer neurons to hardwire different behaviors, so it pays to be flexible anyway.


References

Nice, C.C. & Fordyce, J.A. (2006) How caterpillars avoid overheating: behavioral and phenotypic plasticity of pipevine swallowtail larvae. Oecologia, 146, 541-548.

Papaj, D.R. (1986) Conditioning of leaf-shape discrimination by chemical cues in the butterfly, Battus philenor. Animal Behaviour, 34, 1281-1288.

Papaj, D.R. & Newsom, G.M. (2005) A within-species warning function for an aposematic signal. Proceedings of the Royal Society B-Biological Sciences, 272, 2519-2523.

Weiss, M.R. & Papaj, D.R. (2003) Colour learning in two behavioural contexts: how much can a butterfly keep in mind? Animal Behaviour, 65, 425-434.

Labels: biodiversity, cool bugs, ecology, insects

Go to Geek Counterpoint for the latest Tangled Bank installment, addressing topics from genetics to exoplanets to the continuing discussion about Wikepedia's accuracy.

Labels: carnivals, ecology, environment, genetics

Either the media or the public (seems to be a bit of a chicken and egg question) seems to want every problem to be defined in black and white terms. If you are Josephine Public, this makes sense because we all would love easy answers to the vexing problems that confront society, even as we know deep down that there usually aren't any. The media aggravates this problem with their desperation to oversimplify stories for fro yo-easy consumption, and yet to create controversy at the same time. It accomplishes both to declare emphatically that if you have a nagging weight problem, it is not your fault, it is all in the genes, while other media outlets exhort us to eat less and exercise more, so we can enjoy thin, fulfilling lives.

There are a few reasons why the genetics of obesity are newsworthy. First, many people believe the obese among us have suffered enough, both from their condition, and from the finger wagging of the thin, and all the chastising is not helping people regain a healthier weight. Second, plenty of research papers do show unequivocally that there is indeed a strong genetic component to weight set point in people. This is nothing new, it has been documented in research journals since the 1980's at least (e.g. Stunkard et al., 1986, in which body mass indices (BMI) of adopted children were compared to those of biological vs. adoptive parents; and Stunkard et al., 1990, in which BMI of identical and fraternal twin sets reared together vs. apart were measured). Third, we live in a time of increasingly rapid advances in biological knowledge, especially in genetics, which has led the media to promote the romantic notion that all problems can be traced to genetics solved by genetic tinkering. With the massive failures in gene therapy of the 1990s all but forgotten, one of the biggest political footballs has become the assumed silver bullet of stem cell research.

There is no reason not to conduct any sort of genetic research; it will always provide information. However, geneticists are reductionists and, because of what they do, overly enamored of the "nature" side of the nature/nurture debate. Our recent breakthroughs in genetics, coupled with the politically rightward trajectory of the western world, has recently given "nature" hugely disproportionate emphasis. These cultural and political swings occur back and forth over time. But just as the political moderates are drowned out by the extremists on both sides, so are those of us pointing out that nearly all traits observed in biological organisms, including humans, are a result of the interaction of genetics with environment - the nature/nurture dichotomy is a myth.

The message is so at odds with the popular conception of weight loss — the mantra that all a person has to do is eat less and exercise more — that Dr. Jeffrey Friedman, an obesity researcher at the Rockefeller University, tried to come up with an analogy that would convey what science has found about the powerful biological controls over body weight...Those who doubt the power of basic drives... might note that although one can hold one’s breath, this conscious act is soon overcome by the compulsion to breathe...

Such dramatic statements certainly make for good copy. But what the story's author, and perhaps interviewees failed to mention is the recent increase in average weight and obesity in both western and developing countries that has been well documented (as reported by the multinational Organisation for Economic Cooperation and Development):

...obesity rates have increased in recent decades in all OECD countries for which trend data is available. There remain however notable differences in obesity rates across countries. In the United States, the obesity rate among adults (30.6% in 2002) is the highest in OECD countries, followed by Mexico (24.2% in 2000) and the United Kingdom (23% in 2003). Obesity rates in Continental European countries are lower, but are also rising.

Are those with a genetic disposition for getting fat reproducing at a higher rate around the world than those who are thin? It is unlikely. And why are there lower obesity rates in other western nations and developing countries? There are several major correlates of obesity rates over time and space: fast food, television, and cars (Cheng, 2005), which tend to go together. But it is possible that car ownership alone is enough to cause the weight effect (Bell et al., 2002, from their abstract):

Our main outcome measure was current obesity status and the odds of becoming obese over an 8-year period. In 1997, 84% of adults did not own motorized transportation. However, the odds of being obese were 80% higher (p<0.05) for men and women in households who owned a motorized vehicle compared with those who did not own a vehicle. Fourteen percent of households acquired a motorized vehicle between 1989 and 1997. Compared with those whose vehicle ownership did not change, men who acquired a vehicle experienced a 1.8-kg greater weight gain (p<0.05) and had 2 to 1 odds of becoming obese.

Meanwhile, in European countries, not only do fewer people own cars than in the U.S., but people generally have a different relationship with food there too, tending much more to buy locally, non-mass produced food. The U.S.'s penchant for pursuing the efficiency of mass production may be brilliant in many contexts, but the industrialization of farms and food production is a disaster for human health. Forgetting the reliance on low-nutrition packaged food (no matter how much the label screams "healthy!" at you), we also have a system that, thanks to the U.S.D.A.'s grading system, which ignores nutrition and taste in favor of appearance, makes even "fresh" food unpalatable. It is no wonder that most Americans prefer Big Macs to string beans.

The genes/environment interaction is well known for many species of organisms, and can be referred to as "phenotypic plasticity." For example, there is a species of caterpillar whose appearance depends on when it is born, either spring or summer. All caterpillars feed on oak trees, but in the spring they looks like oak flowers, while in the summer they resemble oak twigs. The difference is striking. There are no genetic differences between the two types - their form depends completely on diet, i.e. whether it consists of flowers or leaves (Greene, 1996). Similarly, there could be two people who both have the genetic disposition to be fat. One that lives a "western" lifestyle revolving around fast food, television, and automobiles, is likely to be fat. The other, living as a subsistence farmer in a town with no electricity and only bicycles and feet for transportation, is not as likely to be fat. Those without the genetic disposition for putting on fat would be thin under either condition.

The obsessive focus by some scientists and journalists on genetics, and by others on environment, is blinding us to the importance of the interaction of the two. Those in the media emphasizing exercise are well-intentioned, but misguided. Human bodies predisposed to putting on a lot of weight are probably not going to be much affected by an hour of "cardio" three or four times a week. We have to take a step back and imagine what it is our bodies are designed to do. In a non-technological world, our bodies are designed to walk - a lot. Some mammals are selected for lying around most of the time, with short bursts of speed and strength occurring at occasional intervals (e.g. lions and other large predators). Other migratory mammals, such as grazers, can keep up a moderate pace for a long time, but must spend a lot of their time eating because they eat a low-energy food.

What humans appear to be designed for is walking and running over long times and distances. There are legends of American Indian lacrosse games on miles-long fields lasting for days, and there was a time when native Mexicans were known for their extraordinary running ability (Dyreson, 2004). Some African hunters follow their game long distances for days. More examples can be found. But because humans are designed for locomotion by foot, "exercise" needs to be better defined. Getting your heart rate up once in awhile, with the great majority of the time being spent at rest, is simply not what humans are designed to do, and thus our bodies will not be in the proper balance of nutrient use vs. storage. Obesity research makes it clear that it doesn't necessarily matter how many calories you burn while you are exercising. Weight is much more complex than "calories in, calories out." A common big difference between those who are thin and those who are fat is that for the thin people, walking is incorporated to a much larger degree into their daily life.

What can someone living a western lifestyle do? I am not a dietitian or a doctor, but the research suggests that if you are someone who has a tendency to be overweight, whose diets work for a while but never for good, who has tried working out at the gym to no avail, the only way to lose weight over the long term is to make sweeping lifestyle changes, that include a lot of walking every day, in addition to periodically more strenuous exercise. I am not someone who is naturally thin. A post-pregnancy regimen that got me back into shape quickly was at least 4-5 miles of walking per day, usually weight(=baby)-bearing, plus more strenuous workouts 4-5 days a week (if I reduced that to just 3 days a week, it kept me in a holding pattern, but I didn't make any progress on my conditioning).

Maybe you can't walk to work from your house, but maybe you could find a place to park two miles away. But maybe your commute's too long already, though, to add an hour and a half to it. Maybe you are spending so much time away from home, or it takes so much extra effort to find real food, that it seems unthinkable to prepare anything but pre-packaged foods. Unfortunately we have developed our way into a lifestyle corner that is not amenable to staying within the normal parameters for being human.

The media, government, and non-governmental organizations can talk about genes and diet and exercise until they are blue in the face. As long as we continue to build exurban communities with zoning that requires complete dependency on cars to do the briefest errand, often to the fast-food place which is much closer and more accessible than a local farmer's market, a lot of people will continue to be fat. But despite the realities of modern U.S. life, if we do not find a way to change the policies that lead to these destructive lifestyles, we are dooming many of ourselves, and our children, to a lifetime struggle with health. Instead of living our lives, many more of us will be dealing with constant health problems, which all of us will pay for, one way or another. Fortunately in the U.S., it is truly possible to effect substantive change at the lowest local level. If we do not, Dr. Friedman, we only have ourselves to blame, genes be damned.


References

Bell, A.C., Ge, K., Popkin, B.M. (2002). The road to obesity or the path to prevention: motorized transportation and obesity in China. Obesity Research 10, 277–283.

Cheng, T.O. (2005) Fast food, automobiles, television and obesity epidemic in Chinese children. International Journal of Cardiology, 98, 173-174.

Dyreson, M. (2004) The foot runners conquer Mexico and Texas: Endurance racing, indigenismo, and nationalism. Journal of Sport History, 31, 1-31.

Greene, E. (1996) Effect of light quality and larval diet on morph induction in the polymorphic caterpillar Nemoria arizonaria (Lepidoptera: Geometridae). Biological Journal of the Linnean Society, 58, 277-285.

Stunkard, A.J., Harris, J.R., Pedersen, N.L. & McClearn, G.E. (1990) The body-mass index of twins who have been reared apart. New England Journal of Medicine, 322, 1483-1487.

Stunkard, A.J., Sorensen, T.I.A., Hanis, C., Teasdale, T.W., Chakraborty, R., Schull, W.J. & Schulsinger, F. (1986) An adoption study of human obesity. New England Journal of Medicine, 314, 193-198.

Labels: behavior, health, humans

The blog carnival Oekologie #5 is now up at The Voltage Gate. With the wide variety of posts up about plants, animals, and their environment, there is something for everyone.

Labels: carnivals, ecology

There may be a reason why placental mammals, such as ourselves, were greatly more successful evolutionarily than marsupials (which, other than opossums, are restricted to Australia). Researchers have looked for possible constraints related to the marsupial reproductive system, which is the major difference between the two groups. Marsupials have very brief gestational periods, after which the young, still at the embryonic stage, are born from the uterus and climb along the outside of the mother's body to to a teat, which expands in the embryo's mouth to provide a strong point of attachment. Most, though not all, marsupials have pouches which protect the young at this vulnerable stage. The entire fetal stage of development occurs outside the mother's body.

In a lightning search, I found one interesting paper (Sears, K.E. (2004) Constraints on the morphological evolution of marsupial shoulder girdles. Evolution, 58, 2353-2370) which finds statistical evidence that there are constraints on the scapula (shoulder blade bone) due to the embryo's need to climb to the teat at such an early stage. This has apparently limited diversification in the structure of this bone, which in turn imposes constraints on locomotion. (The scapula is an extremely important site for muscle attachment; in humans, 13 muscles attach there). Simply stated, there may be a lot fewer marsupials than placentals out there because there are fewer ways to get around, and thus fewer niches available for them to expand into.

So, it was probably more likely that large-brained types like us would be placentals. But maybe it wouldn't be impossible. So I like to imagine sometimes the convenience that being marsupial would provide to the reproductive half of our species. For instance, in placentals like us, body resources are preferentially diverted to a developing fetus; we cannot control the process. If resources are scarce for a marsupial mother who is unable or unwilling to provide for her young, she does not have to. All she has to do is remove the embryo from the teat. (Marsupials are known to do this for various reasons, including sexual selection of the young.)

If humans were marsupials, there would be no abortion debate. This is because the abortion debate is not about life, it is about control. Because a placental woman cannot remove a developing fetus easily by herself, this action can be controlled by other people. There would be no possible way to prevent the removal of a dime-sized embryo from someone's body.

There are a lot of people out there who I am sure are outraged by my characterization of the abortion debate. But it is obvious to many of us that the political debate is not about the sanctity of life, or the definition of life, or the point at which life begins, or anything to do with life. All of these discussions are obfuscations. If it were about any of these, there would not be the large overlap there is between anti-abortionists and those who are pro-capital punishment, those who support a war that has spurred the killing and maiming of generally hundreds of innocent civilians (including a hefty number of children) per week, and those who are anti-birth control. Anti-abortionism is also a fairly recent phenomenon in Christian history. Therefore it is actually a political movement, not a foundational religious moral issue. But others have pointed out these inconsistencies before.

The interesting analysis is in what human behavior we attempt to regulate. Certainly there is a largely "golden rule" theory behind many of our laws. (Despite Christian Right assertions that our laws are based on the Biblical Ten Commandments, the evidence belies this because only two transgressions listed, murder and theft, are against the law and both are necessary for a stable, functioning society. The others are not.)

But there are also repeated attempts, some successful, others not, to legislate morality at a level that is not necessary for a stable society. Abortion is clearly one of these. Other examples I can think of are Prohibition, anti-sodomy laws, and anti-drug laws (which arbitrarily leave out a slew of drugs, including nicotine, caffeine, alcohol, and those deemed to have a medical purpose). Of these, only the last are still extant, and it would be a stretch to argue that they are in any way effective. But, it is at least possible, as it was during Prohibition, to nab someone with the goods and therefore punish a few token perpetrators. Sodomy laws were also largely unenforceable, aside from a few tokens, and have mostly been abolished. One can be caught in the act of sodomy, but it is harder than catching someone with drugs.

Why don't all these political Christian anti-abortionists demand other laws that could be deemed equally moral? For example, why does no one propose to make adultery illegal (as it is in many religiously based societies)? My guess is that lawmakers, because they are in positions of power, engage in it often and don't want their fun dampened. But another reason is that such a law would be about as easy to enforce as an anti-sodomy law. And what about greed, one of the seven deadly sins, specifically prohibited by the Ten Commandments? That would be inconvenient too, since it keeps our economy churning along. And of course one cannot attempt to regulate thought in a "free society."

But abortion is a winner. First, because it affects only women (and a few rogue doctors), which most of our lawmakers are not. Second, because pregnancy is the scarlet letter for many communities. It is God punishing the woman for fornication. It just so happens there is no scarlet letter for men (aside from a few diseases, and you couldn't legislate against the curing of a disease, could you?) so even those who believe men should be equally punished for such activity have no way of proving it. There's no point, so the men are safe.

For placental humans, anti-abortion laws are much easier to enforce than many morality laws, because either you go have it done by a doctor in a sterile facility, or you take your life in your hands. Certainly some people have opted for the latter approach when abortion has been illegal, but anti-abortion law remains relatively enforceable.

But if we were marsupials, there would be no scarlet letter for women, either. The disposing of an embryo would be so quick and easy it would be nearly impossible to catch someone in the act. So, we wouldn't bother. There would either be no attempt at anti-abortion law, because it would be acknowledged to be unenforceable, or, a law would pass without fanfare and hang out on the books forever, but be meaningless and unenforceable (somewhat like recent remnants of anti-sodomy laws). So no debate. But as we are, that power could be wielded easily, and so attempts to wield it will never end.

Labels: gender, health, humans, morality, religion

Trap-jaw ants are the venus fly traps of ants, in the tropical/subtropical genus Odontomachus. They are some of the most incredible animals on earth, because of the speed at which they can snap their jaws together to snatch their prey. The species at left, O. clarus, is one I encountered in Arizona. Like many desert animals, these ants like to hunt at night, and it was common to see them milling about on the University of Arizona campus in the glow of the street lights. The workers are striking to see because they walk about with their huge jaws in the open position. In the picture you can barely see tiny trigger hairs, which are similar to trigger hairs in venus fly traps. Because this is an animal, though, there are large jaw muscles which contract like coiled springs to hold the jaws open. When there is pressure on a trigger hair, the effect is like unhooking a latch (think of a mousetrap), and the jaws explosively close on their prey, at a nearly unimaginable speed:

"Biologists clocked the speed at which the trap-jaw ant, Odontomachus bauri [at right], closes its mandibles at 35 to 64 meters per second, or 78 to 145 miles per hour - an action they say is the fastest self-powered predatory strike in the animal kingdom. The average duration of a strike was a mere 0.13 milliseconds, or 2,300 times faster than the blink of an eye."

To record the entire motion requires filming the ants at 50,000 frames per second, rather than the usual 24.

In their paper published last August (Patek, S.N., J.E. Baio, B.L. Fisher, and A.V. Suarez, 2006. Multifunctionality and mechanical origins: Ballistic jaw propulsion in trap-jaw ants. Proceedings of the National Academy of Sciences 103: 12787-12792), researchers added to this incredible story by discovering an additional purpose of the trap jaws. They first calculated the force of the mandibles: "...a single mandible could potentially generate a force that is 371-504 times the ant's body weight." Then they documented a previously unknown use for this force in O. bauri: self-propulsion.

You must watch these videos to fully appreciate this behavior. But, to summarize, by snapping their jaws against a hard surface, O. bauri achieves "heights up to 8.3 centimeters and horizontal distances up to 39.6 centimeters. That roughly translates, for a 5-foot-6-inch tall human, into a height of 44 feet and a horizontal distance of 132 feet." Of course, whenever comparisons are made between insects and humans, the former come out looking like Schwarzeneggers to the hundredth power. This is because such comparisons do not take into account the effects of scaling. The insect world, with the same gravity and atmosphere as we have, but with exoskeletons and light weight, is a very different place (which is a topic for a later time). Everyone knows you can drop an insect from great height and it will emerge unscathed. This is very useful if your escape route is flying eight times your body length straight up into the air.

To see some amazing biodiversity in action, watch the videos.


More incredible ant pictures are posted at myrmecos.net!

Labels: ants, behavior, biodiversity, cool bugs, ecology, insects

We have seen some recent outbreaks of Escherichia coli O157:H7, the common pathogenic strain of the common gut bacterium, in the human food supply, most notably in spinach last fall.

Since then, it has been common to see assertions in the mainstream media (e.g. by the quite knowledgeable food industry writer Michael Pollan) that E. coli O157 is purely a product of the mega-feedlot industry, because the pathogen is not found in the guts of grass-fed cattle. It is a very attractive assertion to those of us who support a trend away from factory farms, which are demonstrably less healthy both to humans and the environment in many ways. So, I thought it would be worthwhile to investigate this further.

Buried within a forest of "green" sites promoting this idea was a link by a commenter to a brief Kansas State news release claiming that this assertion was false. Dr. David Renter, assistant professor of veterinary epidemiology at KSU, has done research himself on this important human health topic and has studied the prevalence of E. coli O157 not only in feedlot vs. range-fed cattle, but in wildlife as well.

In Renter et al., 2003, he and his colleagues found E. coli O157 in 2.48% of fecal samples from rangeland cattle in Kansas and Nebraska, similar to a rate found in previous studies of "confined" (=feedlot) cattle. They also tested several hundred samples from wildlife, including coyotes, whitetailed deer, raccoons, and possums. In wildlife, the pathogen was only found in one possum sample.

An earlier study (Renter et al., 2001) confirmed the presence of E. coli O157 in fecal samples from wild deer in Nebraska, albeit at the very low rate of 0.25% (a rate of 25 out of 10,000).

Surpirsingly, Kudva et al. (1997) found, in sheep, the opposite trend I expected to see based on media reports on cows. Animals were innoculated with E. coli O157, then fed one of two diets: grass hay, or corn and alfalfa. In this case, grass-fed sheep were shedding bacteria twice as long as corn/alfalfa-fed sheep.

So where did the grain vs. grass theory come from? It turns out it was from a Science paper in 1998 by Diez-Gonzalez et al., which did not specifically address pathogenic E. coli. As explained by Gannon et al. (2002):

A grass diet would certainly be expected to cause a change in the intestinal microflora as well as parameters such as volatile fatty acid species and concentrations and the pH of the digesta. A recent study has shown that grain feeding selects for acidresistant E. coli strains and that feeding Timothy hay rapidly reduces the numbers of these organisms shed in the faeces... While this appears to be the case, the authors of this somewhat controversial study failed to demonstrate that E. coli O157: H7 was one of the acid-resistant E. coli strains selected for by grain feeding and reduced by hay feeding. Recent studies by Hovde and colleagues ... showed that hay feeding increases rather than decreases faecal shedding of E. coli O157: H7 by beef cattle which were orally inoculated with the organism.
... In addition, naturally occurring antimicrobial substances in certain plants may play a role in faecal shedding of the organism by cattle e.g. Duncan and colleagues have shown that certain coumarins derived from plants inhibit growth of E. coli O157: H7.

So, once again, complex nuances in a biological system fail to penetrate the aura of the either-or dichotomy so loved by the media.

There is no doubt that the relationship between E. coli, domesticated animals, and husbandry methods is not simple. As Renter et al. (2003) state:

The observed number of E. coli O157 XbaIPFGE subtypes, the frequency and persistence of specific subtypes, and the presence of indistinguishable subtypes in cattle, water, and wildlife indicate that the molecular epidemiology of E. coli O157 in range cattle production environments is complex. A clear description of the complex molecular epidemiology requires explicit definition of factors related to the molecular biology and micro- and macroecology of the organism.

The "subtypes" to which they refer number, in this study alone, 70 of just the O157 strain that they were studying. Many more exist. There are lots of possible ways to address the likely growing E. coli problem. Antibiotics are one, but there are of course problems with resistance there (Flucky et al., 2007). Hopefully, environmentally friendly rearing practices will be part of the solution, but it is clear they would not be a complete solution. E. coli O157, wherever and whenever it came from, will be with us for the duration. The question is, can we use prevention to keep it to a level that was shown in the wild deer (0.25%), or are we going to try to medicate it out of the system?

It would be wonderful if mass food supply problems had simple management answers - not that conversions of half our cattle back to pasture from feedlots would be easy. There are serious problems with our food supply, and we need aggressive journalists to be informing the public about agribusiness practices that should be changed in order to avoid major public health consequences - the recent melamine pet food scandal is a prime example of where both regulation and enforcement are severely lacking.

We need Michael Pollan and others like him to be watching out for us. But they must make absolutely sure that their credibility remains intact, because we need to know that they are more trustworthy sources than government and corporate spokesmen with obvious agendas. We need someone to be telling us the truth. So either the journalists must improve their scientific literacy enough to do the appropriate research for their story, or they must hire someone who has it already.

(Mr. Pollan, if you are hiring, I am available for freelance work.)


References:

Diez-Gonzalez F, Callaway TR, Kizoulis MG, Russell JB. (1998) Grain feeding and the dissemination of acidresistant Escherichia coli from cattle. Science, 281, 1666–8.

Fluckey, W.M., Loneragan, G.H., Warner, R. & Brashears, M.M. (2007) Antimicrobial drug resistance of Salmonella and Escherichia coli isolates from cattle feces, hides, and carcasses. Journal of Food Protection, 70, 551-556.

Gannon, V.P.J., Graham, T.A., King, R., Michele, P., Read, S., Ziebell, K. & Johnson, R.P. (2002) Escherichia coli O157: H7 infection in cows and calves in a beef cattle herd in Alberta, Canada. Epidemiology and Infection, 129, 163-172.

Kudva, I.T., Hunt, C.W., Williams, C.J., Nance, U.M. & Hovde, C.J. (1997) Evaluation of dietary influences on Escherichia coli O157:H7 shedding by sheep. Applied and Environmental Microbiology, 63, 3878-3886.

Renter, D.G., Sargeant, J.M. & Hungerford, L.L. (2004) Distribution of Escherichia coli O157: H7 within and among cattle operations in pasture-based agricultural areas. American Journal of Veterinary Research, 65, 1367-1376.

Renter, D.G., Sargeant, J.M., Oberst, R.D. & Samadpour, M. (2003) Diversity, frequency, and persistence of Escherichia coli O157 strains from range cattle environments. Applied and Environmental Microbiology, 69, 542-547.

Labels: ecology, environmental toxins, health