From grass to Greeks

Recently I wrote about research into growing muscle cells in the lab to provide animal-free meat. At £50,000 per kilogramme and lacking blood, fat or the texture that whets carnivorous appetites, test-tube meat isn't economically viable. We still have a long way to go to compete with nature.
I was reminded of this on a recent jaunt up Ben Lomond.

My hiker's lunch comprised an excellent roast-beef sandwich. I ate it while watching a herd of cows benignly chewing away at the grass. Cows break grass down to its chemical constituents. They then reconfigure these into new molecular structures that assemble into "cow". In digesting my sandwich, I then convert cow to "man". Life forms operate through enzymes, which perform these astonishing acts of transmogrification. This is biochemistry: the constant inter-conversion of chemical forms by living entities. Grass is made of water, carbon dioxide (from air) and nitrogen, with trace amounts of other elements absorbed from the soil. Sunlight provides the energy that drives the chemical combinations of small chemicals into larger ones that yield the grass that convert to cow, then to man.

The ancient Greek notion that we all derive from earth, air, wind and fire was close to the truth. Harnessing these "classical elements" remains the greatest challenge to human sustainability.

This article first appeared in the 26 September 2011 issue of the New Statesman, The fifty people who matter

Flickr/Jacob Enos
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Personal experiences – not just biology – shape who you find attractive

Researchers find past experiences play a role in identifying why people are attracted to certain individuals.

A new study suggests personal experiences influence our attraction to our preferred partners. It was previously thought genes played a bigger role, as they do in forming other examples of behaviour and character traits. Just reflect on the number of times you've been singled out by a family member for acting like one of your parents, either offensively or in a praiseworthy way.

There are certain characteristics that lead people to judge particular faces as more attractive than others, such as the level of symmetry. However, people still dispute others' opinions when judging facial attractiveness – it's subjective. After all, what else is the purpose of the romantic lead's sassy best friend in any rom-com or book? Or just think how boring conversations with your friends would be without such intense and passionate disagreements.

The researchers used twins as participants in the study in order to monitor these differences and disagreements in opinion. This was necessary because twins are, by definition, genetically identical, allowing the scientists to rule out genetic differences as a reason in explaining their findings.

A total of 547 sets of identical twins and 214 sets of fraternal twins (siblings sharing half of their DNA) were asked to judge the facial attractiveness of 102 female faces and 98 male faces, and give each face a rating based on preference. The results showed, on average, the twins agreed with each other 48 per cent of the time, and disagreed on facial attractiveness 52 per cent. Had the numbers been closer for both the identical and fraternal groups, this would have shown genes were more influential in determining our levels of attraction to others.

The study concluded the reason behind this difference was primarily based on an individual's unique environmental factors (the scientific phrase for "past experiences"), at 78 per cent.

Previous studies have shown aesthetic preferences are based on a range of other factors too, including socioeconomic and cultural features, the rater's own facial features and also personality. (See, it's not always about looks.) The authors were also able to determine how our genes influence facial recognition during this same experiment, if not our preferences.

Discovering that a personality characteristic is influenced by our environment is another highlight in the field of behavioural genetics, as it was previously thought "nature beats nurture" in many aspects of an individual's behaviour. However, this study shows that a person's experiences are unique even between family members.