Category Archives: Biology

MIT’s progress in making synthetic spider silk

From this report [via slashdot]:

“If you look closely at the structure of spider silk, it is filled with a lot of very small crystals,” said Gareth McKinley, a professor of mechanical engineering and part of the group that devised the new method of producing the material.

“It’s highly reinforced.”

The secret of spider silk’s combined strength and flexibility, according to scientists, has to do with the arrangement of the nano-crystalline reinforcement of the silk as it is being produced—in other words, the way these tiny crystals are oriented towards (and adhere to) the stretchy protein.

Emulating this process in a synthetic polymer, the MIT team focused on reinforcing solutions of commercial rubbery substance known as polyurethane elastomer with nano-sized clay platelets instead of simply heating the mixing the molten plastics with reinforcing agents.


Is Steven Pinker right about the evolutionary irrelevance of music?

Just three weeks ago, we looked at a Boston Globe article on the evolutionary significance of music. In it we also noted Steven Pinker’s description of music as having no significance at all: music, according to him, is “auditory cheesecake.”

Now, Babel’s Dawn, a new blog on the origin of speech [here’s the first post], has an interesting commentary on Daniel J. Levitin’s book, This is Your Brain on Music: The Science of a Human Obsession.

Levitin also appeals to common sense. A useless activity that can become a time-consuming, exhausting obsession should not become embedded in the species. […] Common sense is a dangerous line of argument because so much of science history recounts the triumph over a particular bit of common sense (the world is flat, the sun moves, time is absolute). On the other hand, we should not abandon common sense before a Magellan, Galileo, or Einstein comes along to correct us. Speculations such as Pinker’s that offer no evidence and that fly in the face of common sense can claim no special pride of place.

Levitin also argues that music also promotes a more general social bonding and cohesion, not just sexual bonding. He presents some interesting work suggesting a link between sociability and musicality (p. 253). While not conclusive, it is provocative and merits further investigation.

Most important from this blog’s perspective is the suggestion that, “Music may be the activity that prepared our pre-human ancestors for speech communication and for the very cognitive, representational flexibility necessary to become humans.”

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Here’s the Wired interview of Daniel Levitin. Link via the Sound and Mind blog, devoted to music cognition.

Evolutionary relevance of music

Aapparently, humans are hard-wired to enjoy music. What is the evidence?

Researchers at the Montreal Neurological Institute, for example, have scanned musicians’ brains and found that the “chills” that they feel when they hear stirring passages of music result from activity in the same parts of the brain stimulated by food and sex.

If something happens, scientists should be — and they are — asking questions like ‘how’ and ‘why’, and offering their versions of possible answers. What might they be?

Some evolutionary psychologists suggest that music originated as a way for males to impress and attract females. Others see its roots in the relationship between mother and child. In a third hypothesis, music was a social adhesive, helping to forge common identity in early human communities.

But some people are not convinced that there is any evolutionary purpose at all.

… [A] few leading evolutionary psychologists argue that music has no adaptive purpose at all, but simply manages, as the Harvard psychologist Steven Pinker has written, to “tickle the sensitive spots” in areas of the brain that evolved for other purposes. In his 1997 book “How the Mind Works,” Pinker dubbed music “auditory cheesecake” …

Olivia Judson’s agony aunt column

Just take a look at the first Ask Dr. Tatiana column that appeared in the Economist. And, eventually, a book emerged with the same title. From the Economist review:

Olivia Judson’s funny and blissfully original new book …purports to be sex advice offered to the animal kingdom by a universal agony aunt called Dr Tatiana, and amply demonstrates the sheer unyielding ruthlessness of the business of procreation. … She responds with gusto to pleading letters from the Dandy on the Cowpat, a yellow dung-fly who wants to make his sperm more attractive, or Anxious in Amboseli, an African elephant who is diagnosed as possessing SINBAD (Single Income, No Babe, Absolutely Desperate). I-Like-‘Em-Headless-in-Lisbon is a praying mantis who asks Dr Tatiana if she also enjoys the thrilling mid-sex spasms of a partner who has just been decapitated; and we are introduced to a female midge who plunges her proboscis into her mates’ heads and turns their innards to a soup “which she slurps up, drinking until she’s sucked him dry…only his manhood, which breaks off inside her, betrays the fact that this was no ordinary meal.” There are several kinds of spiders, we learn further, “where there can be no doubting the females’ intention to take head, not give it.”

All this is from 2002. Just recently, I learnt that Olivia Judson has a blog, but alas, her blog is behind the NYTimes‘ paywall. So, all I can do is to just link to some extended excerpts in Mark Thoma’s blog: here, here, and here.

Punishment and altruism

An interesting paper in Science (a publicly available summary is here; link via Brain Ethics) shows that human beings’ propensity to punish (unfair acts by others) is correlated with their altruism. This finding is based on a pretty large scale study involving populations in no less than 15 different societies or tribes. The implication is that these two cultural traits co-evolved. Here’s a key quote:

A hallmark of humanity is that people help other people–not just relatives and friends but even complete strangers. Such altruism, which goes beyond the mere exchange of favors and forms the scaffolding of large-scale cooperation in human societies, has long been an evolutionary mystery. On page 1767, anthropologist Joseph Henrich of Emory University in Atlanta, Georgia, and his colleagues take a crack at solving the puzzle, concluding that such helpful behavior may have arisen as a result of punishment.

Reporting on experiments they conducted in 15 different societies on five continents, the researchers argue that altruism evolved hand in hand with a willingness to punish selfish behavior. Their results lend support to models of gene-culture coevolution that propose that cultural norms such as the punishment of unfair actions drive the selection of genes favoring altruism.

What was interesting (to me, at least) was the use of three fairly simple prototype games that allowed the researchers to assess the participants’ inclination towards “costly punishment” and “altruism”. For assessing punishment, they used the Ultimatum Game and Third Party Punishment Game; for assessing altruism, they used the Dictator Game. In case you are not able to access the paper from the Science website, Brain Ethics has a description of the three games (with links).

Over at Reason Online, Ronald Bailey has an article explaining this ‘punishment-and-altruism’ research, and this is his concluding paragraph:

The results are intriguing. It turns out that the societies in which the player ones in the dictator game were willing to give more to the player twos are also the societies in which people were more willing to punish less generous players in the other two games. In other words, societies that punished strongly were also the most likely to have strong altruistic impulses. The moral of the story is that if you want to live in a world of caring generous cooperative people, make sure that you thoroughly thrash all the greedy, chiseling scoundrels you come across. It may cost you, but the world will be a better place. [bold emphasis added]

Evolution in Action, etc.

The prestigeous journal Science has just announced the “Breakthrough of the Year”. The prize goes to — can we have some drumroll, please — “Evolution in Action”. You can read its report here. If you are wondering why a 146-year old idea is being accorded this special status now, you should read P.Z. Myers, who explains that “we’re on the edge of a Renaissance in the discipline [evolutionary biology], if we’re not already in the middle of it.”

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Sunil Laxman has a nice post explaining a recent breakthrough in understanding the genetics of skin colour.

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BBC has a report about some promising research on cancer (leukemia) neutralizing effects of green tea. Doctors warn, however, that it is all still early days.

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For the average woman, life holds not two but three certainties: death, taxes and 35 years of monthly hormonal mayhem. Periods can be wretched. But from a young age, girls are comforted with the promise that the bleeding, cramping and radical mood swings are all part of the special alchemy of womanhood. Menstruation is — to use the mother of all feminine-hygiene euphemisms — a precious gift. Which is why the introduction of a new product that invites women to opt out of the whole ordeal is something of a cultural upheaval. Health experts are predicting that by this time next year, menstruation will no longer be an inevitable function but rather an optional feature, a bit like power steering or pay-per-view.

I am sure this quote piqued your interest. Go read all about Anya, a new contraception pill that also “provides a steady stream of hormones, [thus promising] to quash a woman’s usual cyclical fluctuations, virtually wiping out all the irksome symptoms of PMS”. It is expected to hit the drugstore shelves in the US and Canada in 2006. [Update: Anne Casselman notes some curious side effects mentioned in the article.]