All posts by: Magazine Editor

Zia Mehrabi, University of British Columbia; Erle C. Ellis, University of Maryland, Baltimore County, and Navin Ramankutty, University of British Columbia

Every day there are roughly 386,000 new mouths to feed, and in that same 24 hours, scientists estimate between one and 100 species will go extinct. That’s it. Lost forever.

To deal with the biodiversity crisis we need to find a way to give nature more space — habitat loss is a key factor driving these extinctions. But how would this affect our food supplies?

New research, published in Nature Sustainability, found it could mean we lose a lot of food — but exactly how much really depends on how we choose to give nature that space. Doing it right could mean rethinking how we do agriculture and conservation altogether.

A fair deal

OK, but how much space are we talking about here?

There have been numbers flying around since the early 1990s. Some researchers say a quarter of all the space on earth, while others say three-quarters of all land and sea. Those in the middle ground, however, seem to suggest one half.

Leading scientists are increasingly endorsing the figure, including natural scientist E.O. Wilson, who wrote a book on it, and the former chief scientist at the World Wildlife Fund, Eric Dinerstein. These individuals are mobilizing funds, researchers, computing power and social capital to see what it takes to achieve this vision — through their organizations, The Half-Earth Project and Nature Needs Half.

The idea might seem crazy, but then again, maybe we need crazy ideas to get us to think about the better world we might be able to create.

And there is something about handing over half of the planet to nature that has an air of fairness to it — well, on the side of nature at least.

The global agricultural footprint

The reality is, most people would likely want to help save other species too (aside maybe from mosquitoes and some other pesky creatures). The upside seems massive and obvious — not in the least that our children will be able to enjoy these beautiful beings for generations to come.

But is it possible to conserve so much land and still feed everyone?

Agriculture and settlements already cover 37 per cent of the Earth’s ice-free land, so it’s difficult to see how we could set aside half the planet in a way that honours the needs of other species, without losing some of our agricultural lands.

Dinerstein and his colleagues found that some locations, such as the Midwest United States produce so much food that it would be “delusional” to even suggest returning them to nature.

But previous research didn’t quantify or map the scale of these trade-offs at a fine enough resolution to identify what’s really at stake.

Feeding people and conserving species

Our new research did just that.

It found that conserving habitats for other species could cost up to 29 per cent of the calories we currently produce from our food crops. But it also found that these food losses can be minimized to as little as three per cent depending on how that land is allocated to conservation.

If people manage landscapes so they are shared between agriculture and nature conservation — and make agricultural landscapes more kind to other species — it may bring effective results while avoiding large losses in food availability.

The trick here is making our agricultural landscapes less hostile to other life. This is no small ask.

At the country scale, the study identified places where food losses would be large, including India (22 per cent) and China (12 per cent). These two countries have the greatest number of undernourished people on the planet, 195 million and 134 million respectively. It also identified other areas, such as in Indonesia, that may be less available for conservation than previously thought.

Clearly, conflicts between nature and agriculture need to be navigated carefully. Protecting the world’s most vulnerable, malnourished and food insecure populations must remain a priority. And synergies between conservation and poverty reduction need to be the primary focus.

Large potential co-benefits

But it isn’t all bad news.

The study also showed that giving half the planet to nature could increase temperate and tropical forest cover by 30 to 40 per cent, which would help tackle climate change and so likely reduce the agricultural losses from extreme weather.

What’s more, giving nature space might increase aspects of biodiversity important for crop yields like bees — boosting the amount of food we can produce in a given area — and help to offset some of the losses that might come from conservation.

Paula Ehrlich, the president and CEO of the E.O. Wilson Biodiversity Foundation and head of the Half-Earth Project, shared her thoughts on the scientific study:

“Identifying where conservation areas can protect the most species is key to reversing the species extinction crisis and ensuring a healthy planet for all of life, including people. Once identified, conservation protections must integrate into their planning and management systems the cultures and economies of Indigenous peoples, who are de facto the original conservationists.”

There can be little doubt that the idea of giving half the planet back to nature is visionary and aspirational. We think these new findings have important implications for how humans see their needs against those of other species.

* * * * * *

Header image by LiCheng Shih.

The authors gratefully acknowledge the contributions of Carly Vynne Baker and Eric Dinerstein to the writing of this article, and Paula Ehrlich for her comments.

Zia Mehrabi, Research Associate, University of British Columbia; Erle C. Ellis, Professor of Geography and Environmental Systems, University of Maryland, Baltimore County, and Navin Ramankutty, Professor, University of British Columbia

This article was originally published on The Conversation. Read the original article.

Elliot Lasson,
Professor of the Practice and Graduate Program Director, UMBC

Back in the day, most teens had some sort of job lined up for the summer. For some, it was an extension of an after-school job they held during the year. For others, it was a seasonal type of job such as working at a drugstore or as a lifeguard in a pool.

Recently, however, that seems to be no longer the case.

While the presence of teenagers in the summer workforce in July 1978 was at 72 percent, the Bureau of Labor Statistics’ Current Population Survey reported a July 2016 teen labor force participation rate of 43 percent. A recent report by the Pew Research Center analyzed the average summer employment rate for 16- to 19-year-olds in June, July and August 2017 and found that only 35 percent of teens has a summer job.

So, what has happened? Speaking as a scholar who studies generational workforce changes, I can say that there isn’t just one answer but several.

Are today’s teens lazier?

A 2017 Bureau of Labor Statistics white paper provides some reasons that might account for the downward trend in teen employment, including increased summer school attendance, increased parental emphasis on education and competition from other demographic sectors.

One common stereotype is that teens have become lazier. In addition, it’s a ubiquitous observation that teens are tethered to technology and have higher obesity rates than in the past. Both of those contribute to the stereotype. However, 2016 data on “NEETs,” young people who are “Neither in Education, Employment, or Training,” put their number at just 7 percent. The relatively stable and low NEET percentage runs contrary to the idea that today’s teens are lazier.

The role of the gig economy

One explanation is that it’s difficult to track employment in today’s gig economy. For example, a teenager may be working building a website for her aunt’s small business and managing the Instagram account for 10 hours a week. Yet, she will fly below the Bureau of Labor Statistics’ radar and is not likely to be counted as employed.

A second explanation may be a function of changes in the national economy and workforce. For example there is the “Amazon effect.” While in the past, jobs selling T-shirts at the mall or boardwalk were quite common, more people are buying their “stuff” online. As a result, retailers and small shops can likely get by with their existing workforce. So, those jobs are not in abundant supply.

Furthermore, Christopher L. Smith of the Federal Reserve has conducted research that found lesser-educated immigrants are taking on jobs that were traditionally teen-occupied summer jobs. Interestingly, there is also competition from older workers who either remain in the workforce longer or are willing to take “bridge” jobs. In 2015, the percentage of participation in the labor force for those 55 and older was 39 percent, compared to 34 percent for those ages 16 to 19.

In some cases, more young people have been interested in nonpaying educational, experiential or social justice programs. Additionally, there is an ongoing interest in “camps” that combine focus on certain skills like coding and writing with some physical activity.

Higher education quests

Other high schoolers may be taking summer courses to better position themselves for college. This is likely more of a factor in middle- to upper-class families for whom a college-bound trajectory is more automatic, yet is perceived as highly competitive by helicopter parents who are often hyper-involved in facilitating the college goal in high school and as far back as day care.

In addition, there are now clearinghouses for travel opportunities and social justice missions which have become more popular among not only college students but also high schoolers. Having one or more of these on a college application is deemed by teens and parents to possibly be the necessary edge to get into an elite college. In fact, according to Andy Challenger, vice president of Challenger, Gray, and Christmas, a national firm that follows workplace trends, parents are not exactly pushing their kids out the door. “Their parents aren’t forcing them to get a job,” Challenger said. “Parents are saying there are other things you can do over the summer that will create value for you – and you don’t have to go flip burgers.”

Finally, there are problems regarding how employers view young workers in general. According to a survey by the National Association of Colleges and Employers, 89.4 percent of recent graduates rated themselves as proficient in their work ethic and professionalism. Yet, only 42.5 percent of employers shared that view.

* * * * *

Elliot Lasson, Professor of the Practice and Graduate Program Director, University of Maryland, Baltimore County

This article was originally published on The Conversation. Read the original article.

Header image by jessp713

Thomas Cronin
Professor of Biological Sciences

When you think about fearsome predators in the ocean, the first thing that pops into your mind is probably a shark. Sure, sharks are OK, with their sleek, menacing shape and their gaping jaws with rows of jagged teeth. But if you were a fish living on a coral reef or cruising along the shore over the sands of a tropical island, you would fear a far more terrifying predator.

Consider an armored, tank-like creature looking something like a lobster. Most are quite small, often tinier than your little finger, though some can be as long as your forearm. This animal doesn’t swim around like a shark; instead, it hides in the sand or in rocky holes in coral, searching the water above with constantly roving eyes. It can snatch prey right out of the water in a tiny fraction of a second.

And it accomplishes this feat without claws. Instead, it’s armed with a powerful pair of what scientists call “raptorial appendages” that end in a brutal hammer or a series of vicious, pointed spines. These prey-catching arms look somewhat like the front legs of a praying mantis, which gives these creatures their name – mantis shrimps.

They’re crustaceans – the group of hard-shelled animals that includes crabs, lobsters and shrimps. The strength of the mantis shrimps’ raptorial arms together with their amazing eyes make them perfect predators.

Massively powerful predators

Mantis shrimps’ raptorial appendages contain massive muscles that can extend them to their full length in hundredths of a second, producing strike forces that in some species can smash through the glass wall of an aquarium or instantly dismember a crab. These smashing attacks are so forceful they produce tiny bubbles in the water. When these cavitation bubbles collapse in a flash of light, they release additional energy onto the target. Boat propellers and turbine blades are often ruined by cavitation forces; mantis shrimps use them to crack the hard shells of their victims.

Other species, with spiny raptorial appendages, impale fish or shrimp with a vice-like grip that allows the mantis shrimp to drag them down into its burrow – often, in the blink of an eye.

Mantis shrimps – properly called stomatopod crustaceans – first appeared in the oceans about 400 million years ago, and have been evolving on their own route to perfection ever since. By now, they are only distantly related to any other living animal, including ones that arose from their crustacean ancestors. They’re so unusual that they seem to have arrived from another planet – in fact, vision scientist Mike Land jokingly calls them “shrimps from Mars.”

There are almost 500 known species of mantis shrimp. However, they stay well concealed in their rocky and sandy burrows, and only a few scientists study them, so there are probably many new mantis shrimps yet to be discovered. Almost all live in shallow, marine waters, and most inhabit the tropics.

Remarkable eyes of the mantis shrimp

Like all crustaceans (insects, too), mantis shrimps have compound eyes – think of the eyes of crabs, bees, or butterflies. Each eye has hundreds of separate facets, each of which is a single unit of the entire compound eye. But mantis shrimp eyes are far more specialized than all other compound eyes, in some ways more than any other eyes biologists have ever discovered.

For one thing, each eye is like three eyes squeezed into one. The three parts all look at the same point in space, much as our two separate eyes focus on the same scene. We use our two eyes to locate an object in space. Mantis shrimps can work out the distance to objects they’re looking at using a single eye.

Two eye parts, at the top and bottom of the eye, are probably involved in this distance vision. The third part is built from parallel rows of facets that run around the middle of the eye like a belt. Usually there are six rows, though a few species have only two. This part of the eye is called the “midband,” and it supports many special abilities.

Further, most mantis shrimps see ultraviolet light – part of the electromagnetic spectrum that causes sunburn in you or me and that is invisible to our eyes. Mantis shrimps not only sense this light, but with their specialized midbands they even see separate colors of it.

This feature is on top of another set of color detectors that see the same visible light we’re used to – but in eight color channels as opposed to the three primary colors we see. Imagine trying to build a TV that looks right to a mantis shrimp. Besides the red, green, and blue colors that your TV uses to create a vivid picture, it would require pixels for violet, indigo, blue-green, orange and a deeper red than we can see.

And the midband can do even more. It can detect the polarization of light – where all the waves vibrate in the same plane. Our eyes cannot see this property of light. Mantis shrimps image things using it.

So putting together all its visual talents, when a mantis shrimp sees a fish, it’s in patterns of ultraviolet colors, eight primary regular colors and polarized light. Their eyes gather all this information and pass it on to the animal’s brain, so it can decide what to attack, when to attack it, how far away it is, and what it looks like in a dozen different ways. It’s hard for a human to even imagine the visual world of a mantis shrimp.

Letting down its defenses

With superpower vision coupled to explosive predatory arms, it seems like mantis shrimps would be invincible. But even these animals have their worries. Mantis shrimps can not only kill other animals, like fish, octopus or crabs. They can also kill each other. This raises a serious problem. Eventually, it’s time to reproduce – but how does a mantis shrimp know when another one it meets wants to mate rather than make a murderous assault?

Mantis shrimps have been forced to evolve ways to recognize when it’s safe to get intimate and to signal their own nonlethal intent. They use their special vision for this too. Mantis shrimps are often brightly colored, and they display patterns – invisible to us – in ultraviolet and polarized light. The complicated displays inform other members of their species, or of different ones, what they plan to do. If their plans include reproduction, and the viewer is of similar mind, then they can safely mate and initiate a new generation of their species.

So, yes – sharks are all right. But do they have bullet-like strikes? Do they have super-vision? Can they take down prey in milliseconds? It’s mantis shrimps that have these abilities, and they use them to become some of the world’s most impressive predators.

Thomas Cronin, Professor of Biological Sciences, University of Maryland, Baltimore County

This article was originally published on The Conversation. Read the original article.

Header image by jeff~