Today’s post is a bit outside the normal orbit of Thinking Meat, but it touches on a couple of themes that are dear to my heart: the immense value of humankind’s pursuit of scientific knowledge, and the urgent need to encourage any human who is so inclined to pursue a scientific career (and conversely, the folly of discouraging or ignoring half of our brain pool on the basis of gender). In particular, in honor of Ada Lovelace Day, I’m focusing on the brilliant contributions of cosmologist Beatrice Hill Tinsley. In her regrettably short life, she accomplished pioneering work that opened up a new field in astronomy.

Beatrice Hill was born in England in 1941 and grew up mostly in New Zealand, where her family moved after World War II. She excelled at not only mathematics and languages but also music; of the possibilities open to her, she chose to focus on astrophysics. In 1961, she completed a master’s program in physics at Canterbury University and married fellow student Brian Tinsley. In 1963, she moved with him to Dallas, where he had a job at the Southwest Center for Advanced Studies.

She got her PhD from the University of Texas at Austin, 200 miles from Dallas. Despite the demands of the long commute, complicated toward the end of her degree program by the adoption of a baby boy, her PhD thesis was, according to fellow astronomer Robert C. Kennicutt, Jr., “one of the most interdisciplinary works of its day, and certainly one of the boldest graduate thesis projects ever undertaken.” (Not only that, she completed it in only a few years, beginning her PhD studies in 1964 and finishing her dissertation in 1966.) She was the first to model the ways that galaxies change over time, using mathematical calculations and computer simulations to examine changes in their chemical composition, luminosity, and color. This ambitious project wove together many strands of both observational and theoretical astronomy. This and her later work had ramifications for our understanding of the size and age of the universe, in addition to helping establish the field of galactic evolution within astronomy.

Her academic career in cosmology was semi-stalled for a while by the difficulty of finding a position at the University of Texas at Dallas and by the need to care for the two children she and her husband had adopted. (UTD treated her particularly shabbily; although she designed its new astronomy department at the university’s request, her letter applying for the job of heading the department received no reply.) After what was by all accounts a difficult internal struggle between her commitment to her family and her realization that it was impossible to fulfill her scientific promise in Dallas, she divorced her husband, leaving the children in his custody, and took a position at Yale, eventually becoming the first female professor of astronomy there.

Tinsley’s life was tragically cut short by melanoma. Diagnosed in 1978, she kept working through her illness, making the best use of the time she had left to her. She died on March 23, 1981. She managed to pack an incredible amount of valuable work into her lifetime, including authoring or co-authoring around 100 papers in her 14-year academic career, mentoring young scientists, and co-organizing a pivotal conference on galactic evolution.

Her story is particularly moving to me because of the extremely difficult choices she faced regarding her children. My own children lived with their father during a significant portion of their childhood, and although logically the choice made perfect sense, as he could provide a better home for them than I could at the time, and I stayed in the same town as they were and saw them every week, emotionally it was deeply stressful. (Tinsley’s father reported that she wondered if the separation from the children triggered the cancer; the very fact that she wondered this indicates how painful the decision must have been for her.)

As a species, we have got to keep on finding better ways of encouraging young women to focus on their own life’s work, whatever it is, with the same seriousness and commitment that young men are expected to bring to theirs, and of combining meaningful work with parenthood (for those who choose it—and it should definitely be a choice, not an unthinking default).

An ad appeared recently on Bloomington buses that said, “You can be good without god.” It seemed like a fairly obvious statement to me, but it took some effort before Bloomington Transit would agree to run the ads. (Atheist ad campaigns like this one are making a modest sweep of the US; billboards with similar messages have appeared in various cities around the country.)

A recent article offers some evidence that morality and religious affiliation (or the lack thereof) are indeed two separate things. The article includes a meta-analysis of existing studies that have investigated the link between a person’s religious affiliation and the moral judgements he or she makes. The idea was to explore two divergent views on how religion evolved: Was it adaptive because it fostered cooperation between individuals who were not genetically related, or did it emerge as a side effect of other cognitive abilities that were themselves adaptations?

Current evidence shows that people make the same intuitive judgements about novel moral dilemmas regardless of their religious background, suggesting that morality and religion are not necessarily linked. It also suggests that the mental machinery underlying religious belief might be separate from that involved in making moral judgements, and that religion did not originate as an adaptation linked to cooperative behavior. One line of evidence involves studies based on responses to the online Moral Sense Test, and a study of a rural Mayan population provides further evidence.

Of course, morality and religion have become linked in the minds of many people, which is why getting those ads to run was not simple. The story of why and how that happened is yet to be fully explained.

You can read more in this article from Science Daily. The research was published as The origins of religion: evolved adaptation or by-product? by Ilkka Pyysiäinen and Marc Hauser. Trends in Cognitive Sciences 14(3), 104–109, 2010.

These days I’ve been experimenting with baking bread using various sourdough cultures. Furthermore, my interest in wine has certainly deepened over the last few years. You could say that I’ve become a big fan of fermentation, and I think sometimes about its importance in human life. My hat is off to whatever curious humans first discovered the process and decided to put it to good use.

Patrick McGovern, an archaeologist who studies human exploration of fermented beverages, believes that it might have been the desire for reliable access to alcohol, not food, that spurred the farming revolution that swept Neolithic culture, largely banishing hunter-gatherer ways from many parts of the world. You can think of this revolution in terms of its benefits: farming allowed for settled and growing populations that fostered the sharing of ideas and nurtured technological and cultural innovations. Alternatively, you can focus on the disease, limited diet, and economic inequities that eventually emerged in farming populations (some scholars go so far as to suggest that agriculture was a bad idea). Either way, it was one of the most significant transitions humans have undergone. Was it really spurred by beer?

McGovern has recently written a book, Uncorking the Past: The Quest for Wine, Beer, and Other Alcoholic Beverages, which describes the role of fermentation in human history. This article from Spiegel Online and this one from The Independent describe some of his research, which involves chemical analyses of clay pots and other vessels that reveal traces of their former contents. So far, the earliest evidence he’s been able to find for human alcohol production goes back about 9,000 years—long enough for a quite respectable history of beer and wine, certainly, but not quite enough to say anything definitive about the role of alcohol in the Neolithic Revolution. He does argue that beer probably came before bread because the discovery of fermentation apparently predated the domestication of grains to the point where they would make a decent loaf. In time, perhaps we will learn things about the development of bread and wine that will clarify their respective places in the story of humankind. Meanwhile, McGovern’s book sounds like a fascinating read. Cheers!

P.S. I just remembered a New Yorker article from last year about beer. Luckily it’s available online; toward the bottom, there’s a section about a contemporary brewer who works with McGovern to recreate ancient beers.

Music is surprisingly mysterious, for something so ubiquitous. For example, it’s not really clear why we generally associate major keys with happy moods and minor keys with more somber feelings. Also, we choose our scales somewhat arbitrarily out of a range of possibilities. Within a single octave, humans can discern about 240 different musical tones, but the ways we divide this complex tonal landscape are fairly uniform across not only western music but at least some other musical traditions, despite the multitude of other options.

A couple of papers from the lab of Dale Purves at Duke suggest that the answers to both questions are linked to the properties of human speech.

A paper in the Journal of the Acoustical Society of America reports on research comparing the tonal qualities of excited and subdued speech and finds that the former contains more major intervals and the latter more minor intervals, which suggests a source for our identification of the emotional qualities of music in major and minor keys. Another paper in PLoS One shows that the musical intervals making up the most widely used scales are those that most closely resemble the harmonic structure of vowel sounds appearing in human speech.

These close links between the tonal qualities of music and speech suggest that one reason music is such a powerful influence on humans is that it uses whatever mental machinery evolved to pay attention to the utterances of other humans (or as the Purves lab web page puts it, “These findings are consistent with the idea that humans have a bias for conspecific vocalizations.”).

You can read an article from Science Daily about this work. The two papers are:

Major and Minor Music Compared to Excited and Subdued Speech, by D.L. Bowling, K. Gill, J.D. Choi, J. Prinz, D. Purves. Journal of the Acoustical Society of America 127(1), 491–503, 2009.

A Biological Rationale for Musical Scales, by K. Gill and D. Purves.
PLoS One, 4(12): e8144. doi:10.1371/journal.pone.0008144, published December 3, 2009.

A new article in The Atlantic has rocked my world in a way that articles anywhere seldom do. David Dobbs explains a new hypothesis regarding genes, environment, and behavior, which he dubs the orchid hypothesis. I’ve written before about genes that appear to make a person vulnerable to things like depression or anxiety, but the vulnerability may be only half of the story. A growing amount of evidence indicates that those carrying such genes may not only be at risk of a particular disorder if they are raised in an unfavorable environment, but may also function at an above-average level if raised in a favorable environment. This could explain a lot about how supposedly detrimental genetic variants could have survived in the population.

As Dobbs points out, it also provides an amazingly different view of human strengths and weaknesses. While most of us, he says, are like dandelions that can thrive pretty much anywhere, the orchids among us respond especially poorly to a bad environment (with depression, anxiety, ADHD, or violence, for example, depending on their genes) but also respond better than the dandelions do to a good environment. Both dandelions and orchids are necessary to make our species what it is; the orchids are an asset rather than a liability.

What is particularly interesting is that Dobbs had himself tested to see which variant of the SERT gene (5-HTTLPR), which is involved in serotonin regulation, he had. There are three variants, or alleles, of this gene, two of which are believed to be linked to a greater vulnerability to depression. He suspected that he had one of these two, and indeed he did, but that news was less distressing to him than it would have been before he learned as much as he did about the orchid hypothesis. I’ve also wondered if I have one of the two higher-risk alleles of that gene, and one thing that has particularly bothered me about that is the possibility that I may have passed it along to my kids. I don’t usually like to put too much emotional stock into scientific results like this, but I have to say that after reading this article, I feel better about whatever genetic heritage I may have brought into and passed along in the world.

Der Spiegel has interviewed Umberto Eco about an exhibit he is curating at the Louvre. The exhibit focuses on the importance of lists to culture and art. It may sound a bit off the wall, but Eco gets at some fundamental aspects of human nature. He says in the interview that people make lists in an attempt to feel like they are managing the uncontrollable diversity and immensity of life. We know we’ll never encompass all of it, but we keep on trying to establish some kind of control. He goes so far as to say that we like lists because we fear death.

This idea of trying to impose some kind of logical order and control on the world seems to me particularly important today, when we have so many choices available to us and so much information to try to assimilate. One example I thought of is that it’s impossible to keep up with all the books being published on any topic or in any genre, so the ubiquitous “Top 10” or “Top 100” list is a godsend. Another is that so many travel destinations beckon; where should we go? I get over 19 million hits on Google when I search on “places to see before you die”; multiple hits all refer to the same “1000 places to see” book, but plenty of other hits refer to a variety of other lists.

I’ve always been fond of “great books” lists and reading lists of all sorts; when I was younger they gave me a feeling of optimism and of worlds opening up in front of me to study and appreciate. However, as Iain Pears writes, in An Instance of the Fingerpost, “It is cruel that we are granted the desire to know, but denied the time to do so properly. We all die frustrated; it is the greatest lesson we have to learn.” In my middle years, I am realizing that I’m not even going to get through all the book lists I would like to, never mind all the individual books in their sometimes perplexing multiplicity. However, I can agree with Eco that having the lists helps me feel like I’ve got at least a tiny handle on infinity. At any rate, I’m not going to stop making them any time soon.

When our long-ago ancestors left east Africa and spread to Europe, how did they get across the currently forbidding landscape of the Sahara? A recent analysis of Saharan plants shows that two peaks in the water-dependent plant population, indicating more favorable climate conditions, might have made human passage through the area easier. The first occurred about 120,000 and 110,000 year ago and another about 50,000 to 45,000 years ago. These dates fit fairly well with the fossil record. in particular, the biggest push out of Africa didn’t begin until around 50,000 years ago, and might have been facilitated by that second relatively wet spell.

The research itself is interesting: By analyzing dust that settled on the sea floor off the west African coast, scientists could examine the carbon isotopes in hydrocarbons from land plants and figure out which types of plants lived there when. (I’m always fascinated by these chains of evidence that start with painstaking examination of tiny relics of the past and reach up to encompass much bigger phenomena like major human migrations; this kind of thing is part of what made Jared Diamond’s Guns, Germs, and Steel so much fun to read.)

This article from the New Scientist has more details. The research was published as Wet phases in the Sahara/Sahel region and human migration patterns in North Africa, by I.S. Castañeda et al., Proceedings of the National Academy of Sciences, 106(48), 20159–20163, 2009.

It’s easy to wonder to what degree humans are still subject to natural selection; from the perspective of someone living in an industrialized western nation, it can look like everyone gets to live long enough to reproduce and can successfully raise their offspring to adulthood. Of course, in some parts of the world, that’s much less certain than in others, and furthermore, evolution is complicated. A new study, using data from the Framingham Heart Study, has found that natural selection does still seem to be at work on us.

Researchers used data from the 60-year Framingham study on more than 2,000 post-menopausal North American women. They examined the relationship between roughly half a dozen health-related traits and the number of children a women had, adjusting for things like income and education and assessing the way the traits might affect one another. The result indicates that humans are still evolving; as best I can gather, the idea is that certain heritable traits are likely to appear in greater numbers in future generations. On the basis of this information, several predictions can be made about the way natural selection is shaping the future of the human species (the female half of it, anyway).

To me, the interesting thing about this is the demonstration that we’re an evolving animal just like all the other evolving animals on the planet. The senior author of the study says we’re “kind of average” in the speed with which we evolve. It might not sound like a big deal, but the idea that current humans are not an end product but rather a snapshot in a long process goes against some deeply ingrained cultural assumptions. Even if you totally accept the truth of evolution and understand at some level how it works, it can be hard to really understand that the concept of “human” (or any other species) is provisional and time-dependent. (I thought of this when I saw the Ardipithecus show on Discovery last weekend, in particular regarding the idea that “humans evolved from chimps” versus the more precise statement that both evolved from a common ancestor, and the question of how exactly to categorize each group of animals during that process of evolution.)

This story from Medical News Today and this one from Science Daily have more information. The work is reported as Natural Selection in a Contemporary Human Population, by S.G. Byars et al. Proceedings of the National Academy of Sciences 107(suppl1), 1787–1792, 2010. doi: 10.1073_pnas.0906199106.

Fans of the surreal, take heart. Recent research suggests that reading stories involving bizarre events that don’t necessarily make sense can temporarily enhance your ability to identify patterns that help you learn new material. Researchers did two studies to investigate the effects of exposure to a “meaning threat,” something that didn’t make sense or that upset typical notions.

In the first study, subjects read either a Kafka short story (The Country Doctor) pretty much as he wrote it, with its strange and inexplicable series of events, or a tidied-up version that was edited into a more conventional story line. In the second study, people were asked to think about aspects of their own past behavior that are contradictory—in other words, to consider the ways that identity is not as unified as we typically assume it is. After this, participants in both studies were shown strings of letters arranged in a strict but subtle pattern. Then they were given new letter strings and asked to identify the ones that conformed to the pattern.

In both cases, the people who were exposed to the meaning threat (the original Kafka story, the idea of a somewhat fragmented identity) not only selected more strings as adhering to the pattern, but were also correct more often than the respective control group. The researchers explain this by suggesting that it’s uncomfortable to have our common-sense expectations violated, and to compensate when that happens, people are more motivated to make sense of what’s going on around them.

It would be interesting to know if this extends to other media such as music or visual art. It’s also kind of interesting to me that one of the problems with the human cognitive apparatus is that we often make connections too easily, through various cognitive biases such as confirmation bias. Finding associations between seemingly unrelated things or events is a source of creativity, and uniting disparate phenomena under a single comprehensive explanation is often a goal of science. On the other hand, finding patterns where none exist (the supposed face on Mars is a classic example) is a less agreeable manifestation of our hunger for meaning. Like so many things about human thought, perhaps pattern-seeking deserves a “Handle with care” label. Goo goo g’joob.

This article from ScienceDaily describes the research in more detail. Or you can look up the paper: Connections From Kafka: Exposure to Meaning Threats Improves Implicit Learning of an Artificial Grammar, Travis Proulx and Steven J. Heine. Psychological Science, 20 (9), 1125–1131.

I went to an interesting talk today, one of Indiana University’s themester activities. Steven Gaulin of UC Santa Barbara spoke about work he has done with William Lassek on the relationship between human brain size and sex differences in fat distribution. It’s a fascinating story. We women are fattier overall than men, and we tend to carry our fat in different places. One thing the sexes have in common, however, is that fat is vital to the brain, the dry weight of which is mostly fat. Could the differences and the similarity be linked?

Gaulin presented several lines of evidence suggesting that fat deposited on women’s hips and thighs provides the material needed to build the unusually big brains (as primate brains go) of their offspring. He also suggested that a link between lower-body fat and cognitive ability in one’s offspring might have driven male preference and thus sexual selection for a low waist-hip ratio (WHR, i.e., a smaller waist and larger hips).

Among the things he discussed is something called maternal depletion, evident in hunter-gatherers but also more subtly observable in American women, in which the amount of hip/thigh fat decreases as women bear more children. Another factor is a link between WHR in women and cognitive ability (the data they used showed a link between lower WHR—i.e., more lower-body fat—and higher cognitive abilities in their offspring). Menarche (the onset of menstruation in young girls) appears to be related not to the amount of body fat but to its distribution (specifically, a greater amount of it on the hips).

Other lines of evidence include the fact that hip/thigh fat is very hard to get rid of; the body seriously taps into it only during the last trimester of pregnancy and during lactation. Also, hip/thigh fat and abdominal fat (the kind men are more prone to carry around) have opposite effects on the body’s supply of two long-chain polyunsaturated fatty acids that are crucial to brain development, docosahexaenoic acid (DHA) and arachidonic acid (AA). As best I could understand it—I’m not a biochemist, so I’m speaking fairly broadly here—the former promotes and the latter hinders the synthesis of these two fats.

I can’t possibly do justice to the entire talk here. In a nutshell, the shape of women’s bodies could be intimately connected, in interesting ways, with the need to nurture the development in babies of these unusually large brains we have. You can check out Gaulin’s web page for more information, including links to papers about the maternal depletion and menarche research.