Culture and Biology

I just finished reading Smail's On Deep History and the Brain. The first few chapters were a boring history of historians writing history... but the last few were pretty fascinating.

It's a common idea that humans stopped evolving the day that civilization started. Cultural change is so profound and occurs on a time scale so much faster than natural selection that it's easy to expect that we are essentially living post-biology. It usually takes millions of years for species to adapt to their environment: modern humans appeared about 50k years ago and we started experimenting with agriculture and cities only in the past 10k. The implication is that we are maladapted to our current lifestyle (which is pretty depressing!). The idea is that we're built to live in small bands on the savannas of Africa, not giant cities in all climates.

My favorite part of this book was where Smail makes the argument that the above idea is untrue - evolution is still affecting humans wherever we experience strong selection pressures - even in the span of a few thousand years. Well-established examples of modern humans evolving include the mutation that allows many of us to digest milk throughout our lives, and the sickle-cell gene which conveys resistance to malaria. I just read an idea the other day that ethanol tolerance may have been selected for to allow citizens to drink disease-free water in the form of beer and wine.

Even more intriguing were the ways that he demonstrated that culture can change biology. He gave many examples of ways in which our biological development is flexible, plastic and responsive to the way we live our lives. Smail describes the theory that much of human biology (especially behavior) develops as flexible "modules" that are affected by the physical and cultural environment. One example is that most primates live in rigid, complex social hierarchies. Most anthropologists believe that most human hunter-gatherers live in egalitarian societies that prevent hierarchies from developing. This "module" may have been suppressed by the culture of human hunter-gatherers and re-activated by modern civilization. Similarly, a friend of mine once explained to me how many modern humans often have overbites because eating soft cooked food fails to fully trigger lower jaw growth.

I also liked how he pointed out the just so story nature of much of evolutionary human biology thought. Just because you can come up with a reason why a certain phenomenon could be adaptive doesn't mean it really evolved for that function. Evolution is random and unpredictable - there are many ways that a given trait could show up. One example is the hypothesis that Hindus have a religious taboo against eating cattle because their farmers relied on them to plow their fields - and couldn't afford to be tempted to kill them during a lean year. Sure it could be true, but there's no way to prove it...

Pop psychologists like to suggest that men are only attracted to young women, and women are only attracted to older (wealthier) men - because this is what would be evolutionarily adaptive to both. Smail points out that the studies that support this idea relied on personal ads - not exactly a representative sample. Furthermore he points out that modern human hunter-gatherers (and likely all our ancestors) don't live this way in the first place. Typically, women gather most of the calories that the family consumes and when men are successful hunting they usually distribute it evenly among their tribe. When men have extra meat, they tend to give it to girlfriends instead of wives. Likewise, women rely on help with childcare more from mothers, sisters, brothers and boyfriends than they do their husbands.

It's intriguing to think about ways in which biology and culture could be intertwined. He discusses all sorts of possible ways - mainly revolving around brain-body chemistry. It's also much more encouraging to think that we're not stuck in a losing battle between biology and culture.

"The debilitating power of want"

I was hanging out with some friends this weekend when one began telling an anecdote about his travels in Central/South America where he routinely met people who, without any thread of material wealth or possession, managed to be much happier than most (US) Americans he knows.

The other interjected the title quote with the suggestion that much of the chronic illness you find in the US (which he may or may not have been implying he hasn't seen in his travels through the developing world), is largely due to stress and continuous dissatisfaction. The first then elaborated with the (absolutely correct) observation that many Americans are hugely motivated by fear and are consequentially perpetually over-wound.

I think there may be something to this. I remember reading a study (I wish I could remember a citation!) where it was suggested that some measure of personal satisfaction correlated with wealth - but only within countries, not between them - i.e. people judge how well they are doing based on how well their neighbors are doing, not against some universal, objective standard.

I also once read an editorial that suggested that Americans were happier in the 1950s then they are now because basic consumer goods that we now consider necessities (e.g. refrigerators and cars) were new, exciting and increasingly becoming available - i.e. people didn't have much, but they were excited and happy as they saw themselves and their neighbors steadily accumulating more and more neat stuff and living better - as opposed to today, where we take all our mountains of stuff for granted and only chaff to see people with fancier, more expensive versions of our own refrigerators and cars.

It sounds kinda funny, but it also resonates with me. My daily 2+ mile bike commute through quiet, residential neighborhoods really isn't a big deal on all but the hottest and rainiest days, yet I constantly find myself resenting all those that pass me in motorized vehicles. If everyone else were on bikes, I'd still arrive at work wet on many days, but I don't think I'd arrive as irritated.

Maybe this is one of those ways in which physiology is really intertwined with culture...

[reference to upcoming article...]

Returning bison to the American Prairie

Some visiting friends mentioned this story.

A nature preserve outside of the twin cities in Minnesota is releasing a few bison into its prairies to explore the possibility of more widespread introductions. I find this very exciting. I love the idea of trying to rebuild some of the wilderness that has been plowed over by civilization. Reintroducing bison seems to be a particularly dramatic and iconic step in this process. Especially now that agricultural land use is shrinking all over the country, converting much of it to (near) original ecosystems seems well-timed.

At the end of the above mentioned experiment, the preserve is planning on slaughtering the animals to demonstrate that such projects can also be economically sustainable. We should increase investments in parks like this all over the country - for ecosystem services such as (cheap) clean water and storm buffers, for recreation (including fishing and hunting) and to help cultivate a sense of place and the appreciation of the public.

Science communication

I just watched an episode of Nova titled "the four-winged dinosaur." I don't think I've ever seen the real process of science portrayed nearly as accurately. They follow different teams of scientists as they debate a big question (whether birds are descended from dinosaurs) by differently interpreting the evidence surrounding a tiny detail (the angle that the fossil leg seemed to fit into the hip).

Check it out! You'll come away with a much better appreciation for how science actually comes to definitive conclusions and why it so often doesn't quite.

Research burning

The California wildfire season is well under way. and it's only July. I had heard there were some small fires in Sonoma County and it occurred to me that my field sites may burn this year. I'd have to say it would be a cathartic way to end the frustrating experience of gradschool!

Here's a blog that includes some maps of the wildfires in Big Sur. When I heard that they were evacuating the area I became a little concerned about the research sites that some of my labmates have down there. I didn't think much of it at first since our lab's sites seems to revolve around moist redwood-tanoak ecosystems - then I heard a description on NPR from a firefighter that had watched pre-heated redwoods literally exploding into flames.

I went upstairs to check in with the boss to see if anyone we worked with was being hurt by the fires. Our one colleague who currently lives down there is okay and was assisting with the evacuation. When I asked my boss if the fires were impacting any of his sites he asked: "want to see?" He showed me a map of the coast and the locations of hundreds of his sites (part of a long-term ecosystem study of sudden oak death). It seemed that half to most were exposed to the fires! I was glad to hear him continue to explain that they had just finished collecting all the data they needed from these sites a few months ago. The lab is now well placed to address the impact that wildfires have on sudden oak death in California ecosystems.

It's encouraging to hear a story where fate works out in a scientist's favor!

Bioregionalism

I came across an interesting idea the other day that's been around for some time.

Bioregionalism is a philosophy that celebrates the diversity of endemic cultures - primarily as a reflection of local environment. It looks to the embrace of local environments and history in order to produce diversity in the face of globalization. It'd be great to have all the economic benefits of free trade without losing fascinating regional differences in attitudes, accents, food and design. I guess this ties in with my earlier post on The Big Sort. Maybe once again, the advance of globalization will defy critics by leading to increased local heterogeneity and self-determination.

And, because I love maps!

Location, location, location

As any interested parties have surely already learned, Richard Florida has been promoting his most recent book, Who's Your City. For any of you who don't already know, Florida has written a series of interesting books describing how the current job market and socio-political climate is largely shaped by individuals congregating in parts of the country that they find appealing - e.g. adventurous software engineers and scientists heading to the Bay Area. I've enjoyed many of his past books and plan to read this one too when it hits the library. The website I linked to above has some neat maps showing where certain types of people are accumulating. On a related note, Robert Cushing's book describes how this may be intensifying red state vs. blue state politics in The Big Sort.

As per usual, I heard it on NPR.