Penny Sarchet

Morphomechanical Innovation Drives Explosive Seed Dispersal

Summary How mechanical and biological processes are coordinated across cells, tissues, and organs to produce complex traits is a key question in biology. Cardamine hirsuta, a relative of Arabidopsis thaliana, uses an explosive mechanism to disperse its seeds. We show that this trait evolved through morphomechanical innovations at different spatial scales. At the organ scale, tension within the fruit wall generates the elastic energy required for explosion. This tension is produced by differential contraction of fruit wall tissues through an active mechanism involving turgor pressure, cell geometry, and wall properties of the epidermis. Explosive release of this tension is controlled at the cellular scale by asymmetric lignin deposition within endocarp b cells—a striking pattern that is strictly associated with explosive pod shatter across the Brassicaceae plant family. By bridging these different scales, we present an integrated mechanism for explosive seed dispersal that links evolutionary novelty with complex trait innovation. Video Abstract

Don't let Earth's tapestry unravel

Rampant tribalism is carrying us into a bleak future. We must face reality, and soon, says E. O. Wilson

Digital family planning

Objections to birth-control apps expose how little we understand contraception generally, says Penny Sarchet

Listen in to the electric voices of plants

Nigel Wallbridge, a co-founder of Switzerland-based Vivent, whose device is giving ones peace lily an electronic voice. Electricity is an important way of sending messages throughout a plant. Here, Sarchet talks about Wallbridges new device, called PhytlSigns.

Chimp warrior pairs stay cool under pressure

Its just like the Greek warriors Achilles and Patroclus. Chimpanzees like to head into bathe alongside a close friend--a tactic that lowers stress levels. Individuals of many primate species, including macaques and baboons, form strong, long-lasting social bonds that resemble human friendship. These relationships appear to benefit both males and females: they are associated with higher reproductive success and even longer life.

We're living longer – but are we fit enough?

With lifespans increasing, younger generations need to age more healthier than their predecessors to reduce the burden of diseases that come with old age.

Supergene flip allows males to steal matings

The ruff has one of the weirdest sexual systems in the world all thanks to a large piece of chromosome that flipped over 3.6 million years ago. A type of wading sandpiper, the ruff is named after the showy feathers sported by males around their necks during breeding season. But a rare type of male looks exactly like a female, just bigger. Instead of showing off, it uses sneaky tactics to steal rushed matings.

Starting gun fired on gene editing

The age of changing human genes has begun. Heres your guide to the next medical revolution

Goal: 100,000 genetic clues

The 100,000 Genomes Project is a bold bid to understand the causes of cancer and rare diseases, says Maria Bitner-Glindzicz

Brain on music kills pain of workouts

Sex and drugs and rock and roll. Release of the brains natural painkillers make the first two experiences feel good. Now it seems that these opioids are also responsible for musics myriad effects on mood, pain and well-being, giving clues to how people can harness its benefits. Like other pleasurable experiences, there are two components to enjoying music: anticipation of hearing their favorite song, and then actually hearing it. The brain signaling chemical dopamine, which is linked to reward, is involved in both phases. The brains natural opioids could be key. An experiment carried out by Daniel Levitins team at McGill University in Montreal Canada, showed that blocking opioid signals in the brain by giving people a drug called naltrexone reduces the amount of pleasure they report getting from their favorite song.