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Colin Barras compares the loss of wild traits in our species to that seen in domesticated animals ( 24 February, p 28 ) and discusses what led to domestication of humans. A hypothesis that fits with some of the ideas suggested is that of primatologist Christopher Boehm in his book Hierarchy in the Forest: The …

"Finally! I can look like Ashton Kutcher!" @meisteringeniur celebrates the news that faking faces using artificial intelligence is going to change our world ( 17 March, p24 )

Colin Barras reports a study suggesting primates, which includes us, sacrificed slow-twitch muscle to provide energy for bigger brains ( 10 March, p 10 ). However, this clashes with the idea that early humans were nomadic hunter-gatherers, a way of life for which slow-twitch muscle is essential. With the advent of farming, humans would again …

Following on from your article on colour blindness ( 17 March, p 38 ) and as someone with fairly severe protanopia (a reduced sensitivity to red light), I was dismayed to read elsewhere that screening for colour blindness in UK schools is at best patchy. Affected children will be unable to create or understand a …

It is worth noting that what you describe as "full colour vision" in humans is nothing of the sort, and that colour blindness is a relative concept. Humans usually have three types of colour cone, so are trichromatic. But some species have four colour cones, making them tetrachromatic. In a world of tetrachromats, trichromats would …

Alice Klein's look at the use of batteries for storing renewable energy and sharing it in South Australia is full of hope, but premature ( 10 March, p 22 ). A week later, an election put a conservative government in power. We have had two major power failures here recently – one when pylons blew …

Clare Wilson took a look behind recent headlines declaring that antidepressants really do work ( 3 March, p 27 ). Those headlines, based on a study of hundreds of trials of these drugs, seemed to add up to a call for an increase in the use of antidepressants. Up until then I had been hearing …

The prospects of meaningfully tackling climate change by capturing and using carbon dioxide seem slim, as Michael Marshall states ( 17 March, p 34 ). He quotes Peter Styring as bluntly stating that stopping burning fossil oil is the only solution. In addition, a participant from the Sackler Forum is quoted as saying "Carbon dioxide …

You quote Peter Styring on possible uses of carbon dioxide, saying: "I can take a slurry of calcium oxide, put CO 2 into a bottle, shake it up and it'll react very quickly ." Yes; but how does he get his calcium oxide? It's made by heating calcium carbonate. This looks like a chemistry version …

Alastair Malcolm says extraterrestrials may be shy of contact with us out of fear of another technological civilisation ( Letters, 3 February ). Equally, perhaps Earth is nothing special. Life forms inconceivably more advanced certainly exist and perhaps observe us. But why should they wish to engage in two-way communication, any more than we do …