The Infection Metaphor

Every age has its signature afflictions. Thus, a bacterial age existed; at the latest, it ended with the discovery of antibiotics. Despite widespread fear of an influenza epidemic, we are not living in a viral age. Thanks to immunological technology, we have already left it behind. From a pathological standpoint, the incipient twenty-first century is determined neither by bacteria nor by viruses, but by neurons. Neurological illnesses such as depression, attention deficit hyperactivity disord...

 A 1700s Rich Man in Britain

The best that we have seen so far is a poor guide to what is possible. To get some inkling of this, consider the life of a rich man in Britain in 1700—a man with access to the best food, health care, and luxuries available at the time. For all his advantages, such a man could easily die of smallpox, syphilis, or typhus. If he needed surgery or had a toothache, the treatment would be agonising and carry a significant risk of infection. If he lived in London, the air he breathed would be seve...

 Hawking Considers Computer Viruses Life

A living being like you or me usually has two elements: a set of instructions that tell the system how to keep going and how to reproduce itself, and a mechanism to carry out the instructions. In biology, these two parts are called genes and metabolism. But it is worth emphasising that there need be nothing biological about them. For example, a computer virus is a program that will make copies of itself in the memory of a computer, and will transfer itself to other computers. Thus it fits the...

 Heritable IQ is Boosted by Environment, Just Like Height

hough it’s not easy to pinpoint the causes of the rise in IQ scores, it’s no paradox that a heritable trait can be boosted by changes in the environment. That’s what happened with height, a trait that also is highly heritable and has increased over the decades, and for some of the same reasons: better nutrition and less disease. Brains are greedy organs, consuming about a fifth of the body’s energy, and they are made of fats and proteins that are demanding for the body to produce. Fig...

 Neurons Use Viruses to Share Information and Learn

When genes are activated, the instructions encoded within their DNA are first transcribed into a related molecule called RNA. Shepherd’s colleague Elissa Pastuzyn showed that the Arc shells can enclose RNA and move it from one neuron to another. And that’s basically what retroviruses do—they use protein shells to protect their own RNA as it moves between cells in a host. So our neurons use a repurposed viral gene to transmit genetic information between each other in an oddly virus-like...

 Nicotinamide riboside (NR) Increases NADP

In the first controlled clinical trial of nicotinamide riboside (NR), a newly discovered form of Vitamin B3, researchers have shown that the compound is safe for humans and increases levels of a cell metabolite that is critical for cellular energy production and protection against stress and DNA damage. Studies in mice have shown that boosting the levels of this cell metabolite—known as NAD —can produce multiple health benefits, including resistance to weight gain, improved control of bl...

 Using Feedback to Control Weight

Recent research has shown that exhaust from lungs (part of excretion) is a major factor in weight loss. Burning 10 kg human fat requires inhalation of 29 kg oxygen. This produces 28 kg carbon dioxide and 11 kg water. As food and drinks are temporarily stored in the human stomach and bowels, the body weight is instantaneously increased with the weight of any food or drink consumed. Metabolism is usually divided into catabolism and anabolism, where catabolism is the process of breaking down ...