Ben Goldfarb (W. W. Norton)

ANYONE who has ever crossed a busy road in a metropolis without well-regulated traffic – say, Mumbai, India – will understand the plight of a deer trying to cross a rural highway in the US. Evolution hasn’t prepared deer for encounters with cars or trucks.

In the US alone, over a million crashes between vehicles and large mammals occur each year, with wildlife often ending up as roadkill. Roads and fast-moving vehicles give humans mobility. But for thousands of other species, from butterflies to elephants, the same pathways act as barriers to movement, cutting off some animals from their seasonal migration routes.

Crossings: How road ecology is shaping the future of our planet is the work of environmental journalist Ben Goldfarb. He takes us on an eye-opening road trip that spans continents to show how paved roads, seen as markers of civilisation, disrupt the natural world. Mostly, he travels with researchers in road ecology, an emerging field that studies how traffic changes life for plants and animals nearby.

If roads are a disease, then wildlife crossings – a network of tunnels, overpasses and bridge-like structures that allow animals safe passage – could be the treatment, says Goldfarb. For instance, underpasses helped cut down elk fatalities on the expanded Trans-Canada Highway in Banff National Park, while overpasses were found to protect grizzly bears.

The practice of road ecology, the author emphasises, is a moral mandate. Whether saving species from extinction or rescuing more common ones, animal lovers have their work cut out for them. Even roadkill, Goldfarb suggests, can be managed better to serve ecology.

The carcasses of deer, the most common roadkill, are food for scavenging birds, coyotes and even humans. But, says Goldfarb, consider the plight of the golden eagle of the western US, which, when “weighed down by a bellyful of venison takes about as long as a 747 to achieve liftoff” and risks becoming roadkill itself. A service that drags deer carrion some distance from the road will help the eagles eat in peace.

Even the bustle of traffic can harm wildlife that relies on its keen hearing for survival. In a landmark study, researchers recorded the sound of light traffic within Glacier National Park, Montana. They then played the audio at a well-known pit stop for migrating birds in Idaho and found the noise kept some bird species away from the stretch. Songbirds that did venture into the “phantom road” had to expend so much more energy watching for predating hawks that they were too drained to forage. Consequently, they starved.

Goldfarb says that road ecology shows that “roads warp earth in every way and at every scale”. Yet the problem is only expected to get worse, as new highways are built and a projected 2 billion motorised vehicles, including self-driving cars, will hit the roads by 2030 – twice as many as in 2010.

What is to be done? In the US, there are initiatives to dismantle abandoned forest roads and to protect the migratory routes of animals. In other parts of the world, like biodiverse Brazil, new motorways come equipped with wildlife crossings and the law requires highway operators to gather roadkill data and take injured animals to clinics.

With technology and thoughtfulness, it may be possible to mitigate the worst effects. Goldfarb describes heartwarming small initiatives, such as one in Australia where people care for wallabies and other animals whose mothers have become roadkill, or one in Alaska, where moose roadkill is being delivered to hungry families.

Such efforts won’t be enough, however. “Individual drivers can’t make roads lie lighter on earth, any more than people swapping out light bulbs to solve climate change,” writes Goldfarb, making it clear it will have to be a colossal, planet-wide effort.

This is a rare, beautifully written book, which tells us hard truths about roads, cars and life on Earth, but still manages to make us feel positive about the road ahead.

Vijaysree Venkatraman is a science journalist based in Boston

A Quantum Life: My unlikely journey from the street to the stars

Hakeem Oluseyi and Joshua Horwitz

Ballantine Books

“It would take a lot more than hard work to earn his PhD, but Hakeem Oluseyi was up for the challenge”

, danced, and stumbled our way to civilization

Edward Slingerland

Little, Brown Spark

SOME years ago, when author Edward Slingerland gave a talk at a Google campus, his hosts ushered him into an impressive room. This is where coders pop in for liquid inspiration when they run into a creative wall, they told him. It wasn’t a place to get drunk alone.

In his engrossing book, Drunk, Slingerland writes that such spaces, which allow for both face-to-face communication and easy access to alcohol, can act as incubators for collective creativity. The boost that alcohol provides to individual creativity, he emphasises, is enhanced when people get drunk in groups.

For millennia, people have used alcohol and other mind-altering substances to get high. Some archaeologists even suggest that the first farmers were driven by a desire for beer, not bread.

If intoxicants were merely hijacking pleasure centres in the brain by triggering the release of “reward” chemicals, or if they were once adaptive but are vices now, then evolution would have put the kibosh on our taste for these chemicals, says the author. So, what is going on?

Slingerland, a philosopher at the University of British Columbia in Canada, has a novel thesis, arguing that by causing humans “to become, at least temporarily, more creative, cultural, and communal
 intoxicants provided the spark that allowed us to form truly large-scale groups”. In short, without them, civilisation might not have been possible.

This may seem an audacious claim, but Slingerland draws on history, anthropology, cognitive science, social psychology, genetics and literature, including alcohol-fuelled classical poetry, for evidence. He is an entertaining writer, synthesising a wide array of studies to make a convincing case.

Without a science-based understanding of intoxicants, we cannot decide what role they can and should play, he stresses. In small doses, alcohol can make us happy and sociable. But still, consuming any amount of intoxicant can seem stupid, he concedes, because the chemical targets the prefrontal cortex. This late-maturing brain region is the seat of abstract reasoning, which also governs our behaviour and ability to remain on task. small children are very creative because their prefrontal cortex is barely developed.

“A childlike state of mind in an adult is key to cultural innovation – intoxicants allow us to access that state”

A childlike state of mind in an adult is key to cultural innovation, argues the author. Intoxicants provide an efficient route to that state by temporarily taking the prefrontal cortex offline, he says.

Slingerland cites . Prohibition has a long history, with local bans dating to the early 1800s. Using state-level imposition of alcohol prohibition as a starting point, researchers compared counties that had been “dry” for a long time to counties that had been “wet,” but which were suddenly forced to close their communal drinking venues. State-wide bans saw a 15 per cent drop in the number of new patents annually in previously wet counties compared with counties with existing bans.

The last chapter looks at alternatives to alcohol, which don’t produce hangovers, liver damage or risk of addiction. In some centres of innovation, he finds microdoses of purified psychedelics becoming popular.

After exploring the stress-busting, trust-building, creativity-boosting, pleasure-inducing aspects of alcohol, Slingerland dwells on its darker side. From drink-driving to violence, he finds there are many kinks to be ironed out before we can use alcohol as a force for good. That, I imagine, will take some doing. This heady book is, ultimately, an ode to Dionysus, the Greek god of wine, and is best savoured as a fresh take on a contentious topic.

Vijaysree Venkatraman is a science journalist based in Boston