Inertia Wins!

Rebecca Wragg Sykes – Kindred: Neanderthal Life, Love, Death and Art (London: Bloomsbury Sigma, 2020)

Each chapter begins with a vignette written in purple prose that is, at times, a little cringey. Once that awkwardness is out of the way, Sykes takes a series of excellent deep dives into different aspects of neanderthal life. Topics include neanderthals’ evolutionary path, their anatomy, tool-making, hunting techniques, social structures, diets, and more. Neanderthals were also artists, with clearly intentional ornamenting of shells showing up in sites dating as far back as 500,000 years ago–more than twice as old as our species.

The most significant difference between neanderthals and Homo sapiens is our social lives. Simply put, sapiens tend to have more complex social relations. Neanderthals, Sykes believes, lived in bands of about 25 people, compared to 50-150 people for our species during its hunter-gatherer days–and millions of people today.

Moreover, while neanderthal artifacts such as obsidian were known to travel a few hundred miles from their origin sites, Sykes believes they were carried by their original owners on their travels. They seem not to have been traders. Sapiens’ artifacts travel more widely, and are too diverse in origin for one person to have made, kept, and carried by themselves. They have to have traded for them from faraway specialists.

Neanderthals did have some division of labor, evidenced through different wear patterns on men’s and women’s teeth, which become more pronounced with age. This indicates more than women gathering while men hunted. Neanderthal women used their teeth in craft-making tasks such as threading, which created tell-tale wear patterns.

Neanderthals had the same family attachments that we have–unsurprising in a species close enough for us to interbreed with–and also had funeral ceremonies that evolved over time. Chillingly, these apparently often involved ritual cannibalism. Scientists can tell this from bone marks. The consistent tidiness of the patterns and the lack of defensive wounds suggest organized ritual, rather than murder.

An overlooked difference between our two species is in our shoulders. Homo sapiens are practically throwing specialists compared to the rest of the animal kingdom. It shows in our brain activity—being able to calculate parabolic trajectories and distances on the fly—and in our anatomy. Our shoulder joints are shaped in such a way that we can throw harder and with more accuracy than other primates.

While neanderthals were capable throwers, they didn’t have quite the same degree of adaptation for it. As a result, while many of our spears were clearly designed solely for throwing, neanderthal spears look to have been dual-use. They could be thrown, but their sturdier design was also good for stabbing and slashing. This is consistent with common injuries seen in neanderthal bones, which are consistent with close-quarters hunting of large mammals.

Perhaps most intriguingly, Sykes argues that neanderthals’ end as a distinct species had more to do with assimilation than with competition—and might have happened after the mostly Europe-based nenaderthal species migrated all the way to China.

My own theory has more to do with neanderthals’ smaller group size. As Adam Smith said, the division of labor is limited by the extent of the market. Smaller group size means a less refined division of labor, and less specialization. This was compounded by the fact that neanderthals engaged in less trade than Homo sapiens. Our larger group size, plus our tendency to trade over long distances was a double blessing for our species, and a double curse for neanderthals.

This is compatible with Sykes’ assimilation thesis–and most modern humans have 1 or 2 percent neanderthal DNA. But over the long run, my hunch is that sociability, trade, and division of labor were the engines that mostly drove that car.

Rob Dunn – Never Home Alone: From Microbes to Millipedes, Camel Crickets, and Honeybees, the Natural History of Where We Live (New York: Basic Books, 2018)

This is the kind of book that will make you see your home differently, mostly in a good way. It’s not nearly as icky and creep-crawly as the title makes it sound. Dunn delights in having found a hole in the “market” for scientific research. Most scientists go out in the field to do research, to the point that the places where we spend most of our time are among the least studied by naturalists. Dunn saw this opening and has made a fascinating career of working closer to home—though in the age of COVID-19, he likely has more company than he used to.

Dunn’s methods are also notable. He is a fan of crowdsourcing. For years, he has engaged the public to help him with sample-collecting and species identification. The amateur research he has encouraged has led to countless discoveries of new species and ecological niches. Some of the discoverers are as young as 8 years old. Backyard science turns out to be more than a fun activity. There are legitimate scientific discoveries waiting to be made by anyone with a little curiosity, not just professional scientists.

Something that is both obvious and overlooked is that our homes are full of extreme environments. And as a result, extremophiles that were once thought to be exotic are, in fact, extremely common in human environments. Our freezers are as cold as Antarctica, and some of the same, harmless microbes live in both places. Ovens regularly produce temperatures found only in ocean vents and deep beneath the earth’s crust—and host some of the same, harmless species. Our showers and water heaters mimic conditions of geothermal springs. In fact showers host some of the same, harmless, thermophilic bacteria that were once thought only to live in hot springs. Of course, Legionnaire’s disease also thrives in the same environment, but can’t withstand extremophile temperatures. So if you feel guilty about taking a hot shower or bath, don’t. They’re actually safer.

Household microbes and arthropods are nothing to be scared of. They have been in our homes for centuries—precisely as disease rates have plummeted and life expectancy and infant mortality have reached their lowest levels in human history. Just as cats kept rodents and their diseases and feces out of granaries, the spiders in your basement keep fly populations in check. If you like being around lots of flies, all you have to do is kill the spiders. As it turns out, delicate population equilibriums are constantly balancing themselves within feet of you while you sit on your couch and watch tv.

Spaces stations such as Mir and the ISS played/play host to many of the same species as our houses. Wherever we go, there they are. As humanity expands its ambitions in space, this will take on enormous importance. We cannot live without our symbiotic species. At the same time, they can’t overrun our artificial environments. Dunn shows how everyday environments turn out to be fascinating. And his lack of snobbery and emphasis on inclusion are something scientists in every field should learn from.