Letters archive

Alun Anderson describes Robin Dunbar as the "key thinker behind the social brain hypothesis" (19 July, p 48) . But Dunbar was actually a latecomer to the idea, which I and others developed in the 1970s. My 1976 essay "The social function of intellect" was the first of numerous publications on the evolution of brain …

The artificial intelligences we create will lead to an autonomous system that develops technologies "to shape the future of life according to its preferences", writes Nick Bostrom (5 July, p 26) . To have preferences implies consciousness, not a simple weighing of data, however complex and adaptable the rules for weighing. The superintelligence may well …

Nathaniel Hellerstein claims that "by definition we cannot think up programs superior to our own best thinking" (26 July, p 31) . But surely our very existence demonstrates that intelligence does not have to be brought into being by a superior intelligence. Of course some believe this is what happened, but if so, how did …

In discussing genetically modified food, Susan Watts omits two issues that influence public attitudes (26 July, p 26) . In the late 1990s, I attended two large public debates on GM. No one was against the technology itself, as anti-nature, or anti-God. The issues were about who controlled the technology and what risks to the …

It's no surprise that the periodic table is not holding up (12 July, p 38) . There are over 3100 nuclides, but the table only displays 100 or so. It can only be an approximation of something greater. Perhaps it needs further axes to contain its properties, for example, a Z-axis so that each element …

Lisa Grossman writes that a probe that can drill through kilometres of ice is of interest because vapour plumes on Jupiter's frozen moon Europa suggest there is liquid water underneath (26 July, p 10) . If this unknown ocean contains any biology, won't some of the microorganisms come to the surface with the plumes? It …

• Europa's soaring water plumes are indeed a tempting destination for alien hunters. Earlier this year, we discussed plans to fly spacecraft through the vapour to sample it for signs of life (4 January, p 8) .

Aviva Rutkin writes that libraries in the US are becoming workshops (19 July, p 22) . She credits the famous library of Alexandria as the home of the world's first steam engine, although I think that was built in the adjoining university. The library was notable in another way, though, in that entrants as well …

With regard to your article probing the gluten-free debate (12 July, p 28) , when I was a child in Hungary we were taught that Hungarian wheat made the very best bread because it was gluten rich. Gluten was supposed to be good for you. Witney, Oxfordshire, UK

The suggestion that people would rather give themselves electric shocks than sit idly seems to confirm notably cynical observations (12 July, p 12) . For example, it was Bertrand Russell who once quipped, "Most people would sooner die than think; in fact, they do so." London, UK

• Don't ditch the panda, as our headline suggested (19 July, p 38) . Even if one were to interpret the Evolutionarily Distinct and Globally Endangered (EDGE) list for mammals as a plea to reduce conservation efforts for some flagship species, which was never its intention, it would still not be a problem for the …