They Work, They Sting, But Fire Ants Also Possess Rare "Social" Chromosome

Sounds a bit like Mark Zuckerberg?

Fire ant queens in South Carolina
Fire ant queens in South Carolina
Pascaline Minet

LAUSANNE - Is it better to be ruled by one queen or several queens? You can encounter both situations within colonies of fire ants, social insects known for their nasty stings. The fact that both systems coexist as a single species is rare, and until now the factor responsible for it remained unknown.

A new inquiry conducted by researchers in Lausanne, Switzerland concludes that there is in fact a set of genes that determines numerous ant characteristics, for instance, whether they tolerate one queen or several.

The fire ants –- in Latin, Solenopsis invicta -- are known for the severe rashes they leave after using the toxic venom injected through a sting on the bottom of their abdomen. Since their unscheduled arrival in the United States in 1930, these insects from South America kept multiplying, reached Australia a few decades ago and more recently arrived in China. Apart from the danger emanating from getting stung, they are a scourge for both crops and other types of ants they do battling with, according to the study, which has been published in the latest issue of Nature magazine,

The S. invicta knows two models of social organization. The first, called monogyna, has only one regent ruling the workers; the other, polygyna, has several queens within the same colony. In the first case, the new queens born in the community fly off to mate with a male before creating a new nest of her own, far from her original colony. They store a large quantity of fat to feed her larvae. In the polygyna regime, young queens don’t store fat before leaving; once impregnated, they join an already settled neighboring colony to lay their eggs, or they simply stay where they are.

But this species has another specificity that may have a broader significance: The polygyna and monogyna “citizens” are able to mutually detect each other thanks to their scent. This ability allows them to know which regime the other queen belongs to when they meet her for the first time. The communities have strict defensive rules: if the newcomer isn’t fit for their society, they go for the kill.

In order to get to the bottom of it, Laurent Keller’s team of biologists from Lausanne University compared the genome of several queen ants with their descendants. A long-term study rendered possible by the progress made in sequential genetics and data analysis thanks to computer tools from the Swiss Bioinformatics Institute.

Follow the scent

This analysis proved that a part of a chromosome from the fire ant was remarkably preserved from mother to child. This piece of chromosome identified by the scientists comprises 600 genes including the famous Gp-9.

According to Keller and his coworkers, this piece of chromosome, this “super-gene” as they call it, is the source of the social models of the fire ant. It is said to contain determinant information on the ants’ scent, but also the queen’s fat level and other traits linked to the social organization, such as the height of the workers.

“All these genes appear to have been selected to end up together into this piece of chromosome,” explains Keller.

Serge Aron, social insects specialist at Brussels University, calls it a "major step forward, for it’s the only evidence of a "social chromosome" in the animal kingdom.”

Joel Meunier from Mainz University, Germany, says the study provides “a better understanding of how the two community models could survive within the same species all these years.”

As for Laurent Keller, he believes that such a “super-gene” also exists within other insects or even birds.

Such a gene conglomerate running through generations isn’t new for geneticists since the same process applies to the mammals’ Y sexual male chromosome. “The problem with this phenomenon is that the chromosome that won’t recombine will degenerate: that’s why most Y genes aren’t functional,” explains Keller. Nevertheless, this system grants its bearer every aspect that goes with masculinity.

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The Food Truck, A Sign That The White And Wealthy Are Moving In

In San Diego, California, a researcher tracked how in the city's low-income neighborhoods that have traditionally lacked dining options, when interesting eateries arrive the gentrification of white, affluent and college-educated people has begun.

Balboa Park Spring Fling Food Truck festival

San Diego Food Trucks via Facebook
Pascale Joassart-Marcelli

SAN DIEGO — Everybody, it seems, welcomes the arrival of new restaurants, cafés, food trucks and farmers markets.

What could be the downside of fresh veggies, homemade empanadas and a pop-up restaurant specializing in banh mis?

But when they appear in unexpected places – think inner-city areas populated by immigrants – they're often the first salvo in a broader effort to rebrand and remake the community. As a result, these neighborhoods can quickly become unaffordable and unrecognizable to longtime residents.

An appetite for gentrification

I live in San Diego, where I teach courses on urban and food geographies and conduct research on the relationship between food and ethnicity in urban contexts.

In recent years, I started to notice a pattern playing out in the city's low-income neighborhoods that have traditionally lacked food options. More ethnic restaurants, street vendors, community gardens and farmers markets were cropping up. These, in turn, spurred growing numbers of white, affluent and college-educated people to venture into areas they had long avoided.

This observation inspired me to write a book, titled The $16 Taco, about how food – including what's seen as "ethnic," "authentic" or "alternative" – often serves as a spearhead for gentrification.

Take City Heights, a large multi-ethnic San Diego neighborhood where successive waves of refugees from places as far away as Vietnam and Somalia have resettled. In 2016, a dusty vacant lot on the busiest boulevard was converted into an outdoor international marketplace called Fair@44. There, food vendors gather in semi-permanent stalls to sell pupusas, lechon (roasted pig), single-sourced cold-brewed coffee, cupcakes and tamarind raspado (crushed ice) to neighborhood residents, along with tourists and visitors from other parts of the city.

Informal street vendors are casualties.

A public-private partnership called the City Heights Community Development Corporation, together with several nonprofits, launched the initiative to increase "access to healthy and culturally appropriate food" and serve as "a business incubator for local micro-entrepreneurs," including immigrants and refugees who live in the neighborhood.

On paper, this all sounds great.

But just a few blocks outside the gates, informal street vendors – who have long sold goods such as fruit, tamales and ice cream to residents who can't easily access supermarkets – now face heightened harassment. They've become causalities in a citywide crackdown on sidewalk vending spurred by complaints from business owners and residents in more affluent areas.

This isn't just happening in San Diego. The same tensions have been playing out in rapidly gentrifying areas like Los Angeles' Boyle Heights neighborhood, Chicago's Pilsen neighborhood, New York's Queens borough and East Austin, Texas.

In all of these places, because "ethnic," "authentic" and "exotic" foods are seen as cultural assets, they've become magnets for development.

Food vendor at outdoor international marketplace called Fair@44.

Fairat44 via Instagram

A call for food justice

Cities and neighborhoods have long sought to attract educated and affluent residents – people whom sociologist Richard Florida dubbed "the creative class." The thinking goes that these newcomers will spend their dollars and presumably contribute to economic growth and job creation.

Food, it seems, has become the perfect lure.

It's uncontroversial and has broad appeal. It taps into the American Dream and appeals to the multicultural values of many educated, wealthy foodies. Small food businesses, with their relatively low cost of entry, have been a cornerstone of ethnic entrepreneurship in American cities. And initiatives like farmers markets and street fairs don't require much in the way of public investment; instead, they rely on entrepreneurs and community-based organizations to do the heavy lifting.

In City Heights, the Community Development Corporation hosted its first annual City Heights Street Food Festival in 2019 to "get people together around table and food stalls to celebrate another year of community building." Other recent events have included African Restaurant Week, Dia de Los Muertos, New Year Lunar Festival, Soul Food Fest and Brazilian Carnival, all of which rely on food and drink to attract visitors and support local businesses.

Meanwhile, initiatives such as the New Roots Community Farm and the City Heights Farmers' Market have been launched by nonprofits with philanthropic support in the name of "food justice," with the goal of reducing racial disparities in access to healthy food and empowering residents – projects that are particularly appealing to highly educated people who value diversity and democracy.

Upending an existing foodscape

In media coverage of changing foodscapes in low-income neighborhoods like City Heights, you'll rarely find any complaints.

San Diego Magazine's neighborhood guide for City Heights, for example, emphasizes its "claim to authentic international eats, along with live music venues, craft beer, coffee, and outdoor fun." It recommends several ethnic restaurants and warns readers not to be fooled by appearances.

Longtime residents find themselves forced to compete against the "urban food machine"

But that doesn't mean objections don't exist.

Many longtime residents and small-business owners – mostly people of color and immigrants – have, for decades, lived, worked and struggled to feed their families in these neighborhoods. To do so, they've run convenience stores, opened ethnic restaurants, sold food in parks and alleys and created spaces to grow their own food.

All represent strategies to meet community needs in a place mostly ignored by mainstream retailers.

So what happens when new competitors come to town?

Food vendor at outdoor international marketplace called Fair@44.

Fairat44 via Instagram

Starting at a disadvantage

As I document in my book, these ethnic food businesses, because of a lack of financial and technical support, often struggle to compete with new enterprises that feature fresh façades, celebrity chefs, flashy marketing, bogus claims of authenticity and disproportionate media attention. Furthermore, following the arrival of more-affluent residents, existing ones find it increasingly difficult to stay.

My analysis of real estate ads for properties listed in City Heights and other gentrifying San Diego neighborhoods found that access to restaurants, cafés, farmers markets and outdoor dining is a common selling point. The listings I studied from 2019 often enticed potential buyers with lines like "shop at the local farmers' market," "join food truck festivals" and "participate in community food drives!"

San Diego Magazine's home buyer guide for the same year identified City Heights as an "up-and-coming neighborhood," attributing its appeal to its diverse population and eclectic "culinary landscape," including several restaurants and Fair@44.

When I see that City Heights' home prices rose 58% over the past three years, I'm not surprised.

Going up against the urban food machine

Longtime residents find themselves forced to compete against what I call the "urban food machine," a play on sociologist Harvey Molotch's "urban growth machine" – a term he coined more than 50 years ago to explain how cities were being shaped by a loose coalition of powerful elites who sought to profit off urban growth.

I argue that investors and developers use food as a tool for achieving the same ends.

When their work is done, what's left is a rather insipid and tasteless neighborhood, where foodscapes become more of a marketable mishmash of cultures than an ethnic enclave that's evolved organically to meet the needs of residents. The distinctions of time and place start to blur: An "ethnic food district" in San Diego looks no different than one in Chicago or Austin.

Meanwhile, the routines and rhythms of everyday life have changed so much that longtime residents no longer feel like they belong. Their stories and culture reduced to a selling point, they're forced to either recede to the shadows or leave altogether.

It's hard to see how that's a form of inclusion or empowerment.The Conversation


Pascale Joassart-Marcelli is a Professor of Geography and Director, Urban Studies and Food Studies Programs at San Diego State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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