Abbreviated Science Round-up: Mississippi rising, the color of emotion, and why capitalism sucks

Flood control on the Mississippi … has made flooding worse

Years ago—many years ago—I got a degree in aquatic biology. One that says, right there on the diploma, “non-marine.” In collecting that degree, I spent a lot of time overturning rocks in streams and wading small rivers and creeks with buckets, nets, and even electrical gear designed to help me catalog whatever fish lived in those environments. Yes, this does mean I shocked holy hell out of tiny fish. The amazing thing was just how diverse many of those environments turned out to be. A brook barely deep enough to wet your ankles would turn out to be home to toothy grass pike of surprising size, filled with a amazing array of colorful and diverse little Darters, and often host to some unique version of the tiny catfish known as “mad toms”—almost all of which were even then on the brink of extinction.

But sometimes I did my work in streams or rivers that had been channelized—their bends straightened, bottoms scoured, and banks steepened to hasten the flow of water downstream and limit local flooding. When I looked in those streams, even decades after they had been reshaped, they were dead. Not quite completely dead. There was one fish—the Stoneroller—that seemed happy to live in these trenches that once were rivers. But that was about it. Species diversity was uniformly a tiny fraction of an untouched stream. Since then I’ve looked at re-engineering streams as something between murder and genocide. Which means that my reporting on this first article isn’t altogether neutral.

Nature carries both a study from Woods Hole Oceanographic Institution and an article by Scott St. George on the topic of the Mississippi river basin, and the effect of human attempts to re-engineer that basin to reduce the effects of flooding. In some ways, that effort seems spectacularly successful.

Since the late nineteenth century, an expanding system of levees, floodways and channel modifications has gradually brought the river to heel, largely confining its waters to the main channel and accelerating them downstream.

It’s that “accelerating them downstream” part that’s the issue. In squeezing the upper reaches of the river to stop floods there, more water enters the lower reaches of the basin, and it does so more quickly. But detecting just how that water affects flooding can be difficult—after all, not only are 100-year or 500-year floods a relatively rare event, studying them while they are underway involves significant challenges. But the team in this case looked at what floods left behind—high water lines on trees and structures, water left in oxbow lakes, sediment markers of past floods—to extend their database.

Our results, based on a multi-proxy reconstruction of flood frequency and magnitude spanning the past 500 years, reveal that the magnitude of the 100-year flood has increased by 20 per cent over those five centuries, with about 75 per cent of this increase attributed to river engineering.

The other 25 percent comes from from both changes in landscape and from climate change that is leading to more severe weather events. Put all of those things together, and the river is experiencing more severe, more damaging, flooding than before people first started channelizing, building levees, and working to keep the Mississippi in check. 

And all that additional water and energy reaching the lower Mississippi has changed the sediment profile of the river, carried more waste through the delta, and made the entire river system a shadow of what it was when it comes to diversity. But the Stonerollers are probably happy.

Come on in. Let’s science.

Biology

Our viruses evolved with us—and for just as long

Viruses may seem like the simplest bits of life imaginable, but there is simple … and very simple. For example, members of Herpesviridae, which in humans causes chicken pox and shingles, carry between 100 and 200 genes on a double strand of DNA which is wrapped into a multi-layer combination of protein coat and lipid envelope. There are mega viruses with over a million DNA pairs making up more than 1,000 genes. And there are viruses with no DNA at all, but that use RNA for replication. Many of these viruses have fewer than a dozen protein-coding genes. 

A team from the Chinese Center for Disease Control and Prevention took a look at a series of RNA viruses, trying to see just how these invective organisms relate to their hosts. They worked primarily with a poorly studied group of viruses that don’t infect mammals—which has earned them a lot less attention, since they’re not the cause of any known human disease. What they found was that many of the RNA organisms seem to have been there from the beginning, and have evolved along with their hosts, changing slowly over time, but still showing connections to their own ancient ancestors.

Here, using a large-scale meta-transcriptomic approach, we discover 214 vertebrate-associated viruses in reptiles, amphibians, lungfish, ray-finned fish, cartilaginous fish and jawless fish. The newly discovered viruses appear in every family or genus of RNA virus associated with vertebrate infection, including those containing human pathogens such as influenza virus, the Arenaviridaeand Filoviridae families, and have branching orders that broadly reflected the phylogenetic history of their hosts

Note that while these viruses can’t infect mammals, they’re related to those that can. Because it appears that they have been evolving along with us since at least the time of the first jawless fish.

Face color delivers a message among humans

In this case, researchers aren’t talking about the message that color may send in a situation involving guns and people standing in their own back yards. They’re looking at how color conveys emotions in ways that we don’t realize … but do recognize.

Emotions correspond to the execution of a number of computations by the central nervous system. … Here, we study the supplemental hypothesis that some of these computations yield facial blood flow changes unique to the category and valence of each emotion. These blood flow changes are visible as specific facial color patterns to observers, who can then successfully decode the emotion. We present converging computational and behavioral evidence in favor of this hypothesis. Our studies demonstrate that people identify the correct emotion category and valence from these facial colors, even in the absence of any facial muscle movement.

The study shows that people successfully, consistently, and quickly “decode” emotion from these color patterns. They perceive the same emotion from these patterns even when the face they are projected on is otherwise the same. All of this suggests that shifts in skin color are a big part of how people subconsciously decode what they see when they look at another person. And it happens without people even being aware that they’re using these color patterns to decode emotion.

That could have huge implications on numerous fronts.

Ecology

How do you manage ecosystem management?

It’s hard enough to manage a simple system like a business or a factory. An ecosystem, even of a small area, is orders of magnitude more complex and less subject to control, and the ecosystem of a large area, like Chesapeake Bay, would seem almost impossible. So is it worth it to try?

Taking the pulse of an ecosystem is not quite as straightforward as taking the pulse of a person, especially when that ecosystem is the Chesapeake Bay. At 195 miles long and 3,237 square miles in area, the size and complexity of the bay’s coupled social and ecological systems has challenged efforts to assess its health. ... By developing a model of the bay ecosystem that brings data from long-term, large-scale monitoring together with knowledge of the mechanisms underlying those patterns, Lefcheck et al. make a compelling case that ecosystem restoration initiatives of the last 30+ y are paying off.

The results show that active ecosystem management has benefits for both the environment, those who depend on that environment directly, and those who live in the area. Investing in ecosystem management turns out to be a definitively winning move—which makes the fact that both Scott Pruitt and Donald Trump have proposed completely ending the program that supports the Chesapeake Bay project even more unforgivable.

Making the most of carbon capture

Forests absorb huge amounts of carbon. Grasslands much less so. But are their ways to alter the ecology of a tract of land to maximize its potential for capturing carbon?

Strategies to mitigate carbon dioxide emissions through forestry activities have been proposed, but ecosystem process-based integration of climate change, enhanced CO₂, disturbance from fire, and management actions at regional scales are extremely limited. Here, we examine the relative merits of afforestation, reforestation, management changes, and harvest residue bioenergy use in the Pacific Northwest. This region represents some of the highest carbon density forests in the world, which can store carbon in trees for 800 y[ears] or more.

If strategies are limited to “let’s have diverse, old-growth forests,” it’s hard to see how that’s a bad thing. But if we try to engineer the species mix with the goal of producing a tract of land that locks down the most carbon, I worry that, like channelizing rivers, it could have big “downstream” consequences.

ARCHEOLOGY

Two papers this week look at ancient cultures and how they made use of agriculture. Though they’re from different sides of the world, and looking at cultures in two different stages of development, I’m giving them the same quick treatment.

Hunter gatherers didn’t make a fast transition to agriculture

We present evidence that cultivation appeared in Central Anatolia through adoption by indigenous foragers in the mid ninth millennium cal BC, but also demonstrate that uptake was not uniform, and that some communities chose to actively disregard cultivation. Adoption of cultivation was accompanied by experimentation with sheep/goat herding in a system of low-level food production that was integrated into foraging practices rather than used to replace them. Furthermore, rather than being a short-lived transitional state, low-level food production formed part of a subsistence strategy that lasted for several centuries, although its adoption had significant long-term social consequences for the adopting community at Boncuklu. 

Which suggests that the initial value of agriculture vs hunting-gathering wasn’t all that great. Which makes me wonder if the slow increase in agriculture eventually reached a point where it devalued the food resources of the hunter-gatherers.

Mayans engaged in raising animals and long-distance trade earlier than previously known

But the animals they were trading … are probably not what you expected.

An analysis of faunal specimens across almost 2,000 years (1000 BC to AD 950) at the site of Ceibal, Guatemala, reveals the earliest evidence for live-traded dogs and possible captive-reared taxa in the Americas. These animals may have been procured for ceremonial functions based on their location in the monumental site core, suggesting that animal management and trade began in the Maya area to promote special events, activities that were critical in the development of state society. Isotopic evidence for animal captivity at Ceibal reveals that animal management played a greater role in Maya communities than previously believed.

Let’s all pretend that by “procured for ceremonial function” the researchers mean pampered and set on little thrones.

Technology

Electric Tattoos

Inspired by some silvery, but originally non-conductive, tattoo inks, students at the MIT Media Lab have created a process for tattoos that are capable of doing more than just being seen.

The resulting innovation, DuoSkin, is a publicly available fabrication process that enables anyone with access to a craft store, graphic design software, and inexpensive electronics to create gold-leaf temporary tattoos with myriad functions—from advancing songs on a music player to changing color with body temperature. At New York Fashion Week in 2017, models donned DuoSkin tattoos that transmitted information about the garments to audience members’ smart phones.

Northwestern University researcher John Rogers put together the first smart tattoos  2011, but the DuoSkin process seems to open the door for a wide variety of devices—from health monitoring to media—while mixing in aesthetics. And it’s just one of several tattoo-techs that are either coming to market or becoming available to tinkerers. 

Sociology

This explains a lot about our economy

No. Seriously. You need to bookmark this one.

Why has economic inequality risen dramatically over the past few decades even in democracies where individuals could vote for more redistribution? We experimentally study how individuals respond to inequality and find that subjects generally take from richer and give to poorer individuals. However, this behavior removes only a fraction of inequality. Moreover, individuals who give to those who are poorer are generally not the same individuals who also take from others who are richer. These results offer an explanation for the absence of policy interventions that could effectively counter rising differences in wealth: Voters are divided on how to react to inequality in ways that make it difficult to build majority coalitions willing to back political redistribution.

This study encodes our growing economic disaster in miniature. Even when we engage in “wealth redistribution,” We don’t take enough from the rich, don’t give enough to the poor, and don’t engage enough of the population to do either effectively.

Even in a game that had little implication outside its own boundaries, people were unwilling to take action to equalize distribution—even when there was no cost to them to make fair distribution happen. Even when there was benefit to them to make fair distribution happen.

This means that respondents tolerate a considerable degree of inequality even in a setting in which there are no costs to redistribution. Second, redistribution behavior in response to disadvantageous and advantageous inequality is largely asymmetric: Individuals who take from those who are richer do not also tend to give to those who are poorer, and individuals who give to those who are poorer do not tend to take from those who are richer. These behavioral redistribution types correlate in meaningful ways with support for heavy taxes on the rich and the provision of welfare benefits for the poor. Consequently, it seems difficult to construct a majority coalition willing to back the type of government interventions needed to counter rising inequality.

That, folks, represents a heap of work to do.

Image

This week’s image is from Compound Interest. Check there for a larger, easier to read version.