Human biology

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How War Gets “Under the Skin”

Unbending rigor is the mate of death,
And wielding softness the company of life
Unbending soldiers get no victories;
The stiffest tree is readiest for the axe.
(Tao Te Ching: 76)

 

Early in life, our bodies are like unmolded clay, ready to be shaped by our experiences. For some of us, that matching process can create problems. If circumstances change, we could end up poorly adapted to our adult environment. A child born into harsh conditions, though, may have to take that risk in order to make it to adulthood at all.

The Hmong in French Guiana may be an example of this process. They are a fascinating population for many reasons, the most obvious being that they are there at all. A few dozen refugees from Laos first resettled in French Guiana in 1977, a few years after the Vietnam War, after they and the French government agreed that life in small, ethnically homogenous villages in a tropical environment was a better option than acculturating to the cities of Métropole France. The experiment paid off. Today, more than two thousand Hmong are farmers in the Amazonian jungle, producing most of the fruits and vegetables in the country. The result is a level of economic autonomy and cultural retention that is likely unique in the Southeast Asian refugee diaspora.

scenes in fg

Scenes from Hmong villages in French Guiana. (Clockwise from top left: fields of Cacao, young men going on a hunting trip in Javouhey, swidden agriculture of Cacao, a street lined with farmers’ trucks in Javouhey.

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Human Biology of Poverty Symposium

We just finished a symposium on “the human biology of poverty,” held at ISCTE-IUL in Lisbon, and sponsored by the The Society for the Study of Human Biology. It really was a great meeting, full of important research on the effects of various forms of deprivation on biology and health in different populations. The complete program can be found here.

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The Biology of Forced Displacement

“Seeking asylum is not illegal under international law and people have a right to be treated humanely and with dignity.”  – UNHCR

“We crossed the Mekong to get to Thailand at night, so no one would see us. We had always lived in the mountains (of northern Laos), so we did not know how to swim. When we came to the river, we used anything to help us float – bamboo, bicycle tubes. But at night, it is easy to get lost. Someone in our group said: ‘Remember, if you get lost when you’re going down the river (with the current), don’t panic. Thailand is on your right.’ ”

 

 

Every refugee has a story. The one above was told to me by a Hmong man I met in French Guiana in 2001. I went to learn about the experiences of the people there and how they had adjusted to being resettled half a world away, from Southeast Asia to a French ‘overseas department’ in Amazonia. They were actually doing quite well at the time, living as independent farmers who had been given land by the government years earlier.

Hmong men in French Guiana going hunting by bike.

Hmong men in French Guiana going hunting by bike.

They also retained a good degree of cultural continuity. While most are fluent in French, the majority of the 2,000+ Hmong in the country lived in rural, semi-isolated, ethnically homogenous villages. This gave them a buffer of sorts, allowing them to acculturate on their own terms. As they often put it, they were “free to be their own boss,” free to be Hmong, and most said they were happy with life in French Guiana. This combination of traits – economically self-sufficient, culturally distinct, mostly content, living in a rural overseas department – is not the typical refugee story. In fact, because of that relative uniqueness, the French Guiana Hmong have drawn attention from media outlets such as the BBC and the NY Times.

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Developmental Plasticity and the “Hard-Wired” Problem

“Development is the missing link between genotype and phenotype, a place too often occupied by metaphors in the past … But a strong emphasis on the genome means that environmental influence is systematically ignored. If you begin with DNA and view development as “hard-wired,” you overlook the flexible phenotype and the causes of its variation that are the mainsprings of adaptive evolution.” (Mary Jane West-Eberhard, 2003: 89-90)

“Genes, unlike gods, are conditional. They are exquisitely good at simple if-then logic: if in a certain environment, then develop in a certain way… So here is the first moral of the tale: Don’t be frightened of genes. They are not gods; they are cogs. (Matt Ridley, 2003: 250)

 

Plasticity: actor Christian Bale at two points in time. Same genes, different phenotypes.

Plasticity: actor Christian Bale at two points in time. Same genes, different phenotypes.

In his book The Triple Helix, Richard Lewontin told the story of the molecular biologist and Nobel laureate Sydney Brenner, who – while speaking at a conference – predicted that one day we would be able to “compute” an organism (2002). All we would need are two things: the organism’s full genome and powerful enough computers that were up to the task.

The idea is seductive. Genes are sometimes seen as self-sufficient molecules, almost existing in a vacuum, that contain all the information necessary to code for proteins. From there, it’s not a very big logical leap to think that if you had the genome, you could enter the code in some database, hit “run,” and then watch some digitized version of the organism unfold.

In fact, scientists are doing something much like this for the tiny roundworm C. elegans with the project OpenWorm. Yet even for a relatively simple organism such as this, with only about a thousand cells in total, there are reasons to be cautious. As The Economist warned in its write-up of OpenWorm: “Attempting to simulate everything faithfully would bring even a supercomputer to its knees.” However, this isn’t due solely to the limits of computing power (what if we had a super-duper computer!?). Rather, it’s a matter of how the question is framed.

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How War Gets Under Our Skin

beinghuman.org front page

I wrote this piece on BeingHuman.org about how war (and the world in general) gets under our skin. It looks at the Hmong example, as well as examples from a few other wars around the world (the Dutch Hunger Winter, the Biafran famine, and the Khmer Rouge period), and how these experiences get into our bodies. 

 

http://www.beinghuman.org/article/how-world-gets-under-our-skin

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Unbending rigor is the mate of death,
And wielding softness the company of life:
Unbending soldiers get no victories;
The stiffest tree is readiest for the axe.
Tao Te Ching: 76

 

Early in life, our bodies are like unmolded clay, ready to be shaped by our experiences. For some of us, that matching process can create problems. If circumstances change, we could end up poorly adapted to our adult environment. A child born into harsh conditions, though, may have to take that risk in order to make it to adulthood at all.

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Review 2012

Below is a quick look at the most-read posts that were written in 2012, with a brief summary, in case you’re interested.* Thanks very much to everyone for visiting, and to those who have shared these writings and commented on them.

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1) Part 6. Humans are (Blank)- ogamous: Many Intimate Relationships. May 17

This was the most viewed post written this year. It looked at the variety of intimate romantic relationships that humans have negotiated into various socially recognized structures. I tried to go beyond looking at humans as naturally monogamous or promiscuous, which I think are overly simplistic arguments, taking a look at how this complexity may have arisen. There’s also a nice graphic, borrowed from David McCandless.

“We obviously have a lot of cultural diversity in humanity with substantive differences in worldviews and which behaviors are deemed acceptable, but cultures – and individuals – are tasked with how to balance sex, love, intimacy, and commitment, as well as reproduction and parenting. I think this interplay between individual drives and cultures provides an alternate model of looking at things rather than trying to discern what humans ‘are’ in terms of our sexuality.”   

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2) Human Nature, Humility, & Homosexuality. Feb 10

A pointed response to one conservative’s argument about homosexuality being against human nature, and the need for tolerance and the need to avoid making overly confident claims about human behavior. “I would recommend that if we have a choice, then choose humility. Choose tolerance. Choose love.”

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Empathy in Flux

“All is flux.” – Heraclitus

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“Before criticizing someone, you should walk a mile in their shoes. That way, when you do criticize them, you are a mile away… and you have their shoes.”      –Jack Handey

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Stop motion photo of a girl jumping rope. A few moments of an individual life. (Photo by Harold Edgerton).

My advisor in graduate school, Mike Little, once shared with the class that he fantasized about a machine that would provide instantaneous biological data just by having a person walk through it. As he described it, the machine would work something like an airport metal detector, only instead of revealing any concealed objects, it would assess the types of variables that biological anthropologists salivate over – anthropometrics, body composition, blood pressure, hormonal profiles, presence of infections, etc. If only…

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Growing Up in the Two Koreas

The Korean peninsula at night (google earth)

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The above image of east Asia at night is worth more than a thousand words. Below the 38th parallel is the birthplace of my mother-in-law in South Korea, which is luminescent at night as the result of its highly developed economy. My father-in-law was born above that line in North Korea, which today appears to be little more than a shadow of its southern neighbor. Even if one knew nothing about history or geography, they could infer from that single satellite image that there must be a chasm in living standards on either side of the border.

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A full history of the two Koreas and the war of 1950-53 is beyond the scope of this post. What is relevant is that the forces of history and politics took a once cohesive nation and cleaved it in two, having disparate effects not only on the ideologies on either side, but also on the physical bodies of the respective inhabitants. It’s almost as if someone collected a population of dandelions from a single field and then placed them in two different greenhouses for six decades, replete with different soil quality, sunlight, and temperatures, and then observed how they fared. By now, many people have heard something about how North Koreans are significantly shorter than their southern cousins, implying that, like our dandelion example, the conditions for physical growth are quite different in the two greenhouses. John McCain even mentioned this during the 2008 presidential debates to illustrate North Korea’s brutality toward its citizens. How true is this claim?

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Inequality, Health Disparities, & Obesity

An October poll of 1,000 likely voters found that Americans are increasingly concerned about income inequality. When asked: “How Big a Problem is Income Inequality in the US?,” the majority (74%) replied that it was either a big problem or somewhat of a problem. Predictably, there were differences in opinion by political ideology, but a majority of liberals (94%), moderates (81%), and conservatives (55%) answered that inequality was at least somewhat problematic. However, as is true of many polls, it was not specified exactly what people found unsettling about it. I suppose there are many reasons that people might find increasing inequality (and climbing rates of poverty) to be troubling, but I wanted to focus here on inequality and health, particularly on obesity.

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First, what do we mean by poverty? I remember watching an interview on PBS with the economist Jeffrey Sachs years ago (transcript here – thank you, Google), where he distinguished between two types of poverty. The first was an extreme form, which he called the type of “poverty that kills.” The other type was more of a poverty of inconvenience or jealousy. I don’t want to over-interpret Sachs’ meaning. It was a passing phrase in an interview from ten years ago, and his primary focus was on alleviating the extreme poverty faced by more than a billion people in the world living on $1 per day (see Sachs 2005). Elsewhere, Sachs has lamented that the media have ignored poverty in the United States at a time when “the U.S. has the greatest income inequality, highest per capita prison population and worst health conditions of all high-income countries.” His credentials in fighting poverty are unassailable. But I cite the old interview here because I think his descriptions (‘poverty that kills’ vs. ‘poverty of jealousy’) might resonate with many people today, and not necessarily in a good way.

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Extreme poverty: scavenging at a garbage dump in Phnom Penh (abcnews)

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Part 5. Humans are (Blank) -ogamous: Pair-Bonding and Romantic Love

This is the fifth part on the evolution of human mating behavior, comparing evidence for promiscuity and pair-bonding in our species. Please see the introduction here.

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“One of these days I will wake up – which I think I have done already – and realize to myself that I really do love. I find it very difficult to allow my whole life to rest on the existence of another creature. I find it equally difficult, because of my innate arrogance, to believe in the idea of love. There is no such thing, I say to myself. There is lust, of course, and usage, and jealousy, and desire and spent powers, but no such thing as the idiocy of love. Who invented that concept? I have wracked my shabby brains and can find no answer.” (Letter from Richard Burton to Elizabeth Taylor)

“Emotions and motivations (are) hierarchically ordered in the brain. Fear can overcome joy, for example. Jealousy can stifle tenderness…But in this pecking order of basic and complex emotions, background feelings and powerful drives, romantic love holds a special place: close to the zenith, the pinnacle, the top. Romantic love can dominate the drive to eat and sleep. It can stifle fear, anger, or disgust. It can override one’s sense of duty to family or friends. It can even triumph over the will to live. As Keats said, ‘I could die for you.’ ” (Helen Fisher 2004: 97-8)

“Only love can leave such a mark / But only love can heal such a scar.” (Paul Hewson)

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Attempting to summarize the evolution of romantic love and pair-bonding in humans is an enormous task. This is exacerbated by many complications: the literature on these topics is vast; the term ‘pair-bond’ has been used in different ways by different primatologists in the past and is often erroneously confused with ‘monogamy’; the neurobiology of romantic love – which is not a prerequisite of pair-bonding – is complex; the question of when/if humans became pair-bonded in our evolutionary history is highly speculative; and then there is the complicating factor of culture. Furthermore, parts two through four in this series addressed ten biological traits indicating that humans have promiscuity built into us to some degree, and that monogamy, or at least lifelong monogamy, does not come easily.

Gibbons (Hylobates lar). From Wikipedia.

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