Lake Poopó: why Bolivia’s second largest lake disappeared – and how to bring it back



Lake Poopó at a low point in early 2016.
Chiliguanca / flickr, CC BY-SA

Juan Torres-Batlló, University of Surrey and Belen Marti-Cardona, University of Surrey

A huge lake in Bolivia has almost entirely disappeared. Lake Poopó used to be the country’s second largest, after Lake Titicaca, and just a few decades ago in its wet season peak it would stretch almost 70km end to end and cover an area of 3,000 sq km – the size of a small country like Luxembourg. Today, the lake is largely a flat expanse of salty mud.

What happened? We’ve looked into this in various scientific studies over the past few years, and the answer is a mix of both climate factors and more direct human factors such as too much irrigation. This does at least provide some hope: Bolivians cannot reverse climate change themselves, but they can do a better job managing their water.

Map of Bolivia
Bolivia is largely divided between the high altitude Altiplano (grey) and the Amazon basin (green). Lake Popoó is in the centre of the picture, south of Oruro.
Google Maps

Lake Poopó, is found at nearly 3,700 meters above sea level in the “Altiplano”, a large plateau in the centre of the Andes mountains. It is an endorheic basin: nothing flows out, and water is lost only through evaporation. Since dissolved minerals stick around when water is evaporated, the lake is as salty as the ocean – in some places considerably saltier.

Nonetheless, some decades ago Poopó was home to large communities of plants and animals and was a source of resources for the region’s inhabitants. Nowadays, the situation is drastically different. Water levels have declined over the past two decades, and eventually the lake dried out entirely at the end of 2015 after the extreme weather phenomenon of El Niño.

The disappearance of Lake Poopó.

This was ecological devastation. Many of the lake’s 200 or so animal species disappeared, including reptiles, mammals, birds – it hosts a huge community of flamingos – and of course fish. There was also an exodus of rural people to the nearest big cities. Worst affected of all are the Urus-Muratos, an indigenous community whose entire way of life was based around fishing Lake Poopó.

Throughout Lake Poopó’s history, there have been several periods when water levels were very low but the lake used to recover by itself thanks to the rainy season and water from its main tributary the Desaguadero River, which itself drains Lake Titicaca and flows into the slightly lower altitude Poopó.

A river winds through a plateau
The high altitude Desaguadero River.
Stefan Haider / shutterstock

But during the past few decades, much of the Desaguadero was diverted for irrigation, so there was less water left to top up the lake. As Poopó is unusually shallow, mostly just a few metres deep, relatively small changes in overall water volume make a big difference to its surface area. Though the lake has partially recovered due to above-average precipitation in the years since 2015, the situation is still dire.

In our most recent study, we analysed satellite data from the Lake Poopó catchment area over the past two decades and found that more water has been gained through precipitation than has been lost through evaporation. This points to poor management of the water resources in the area, rather than climatic variability, as the principle cause of the lake drying up.

This is not to minimise the role of climate variability. In a separate study, we looked at changes in rainfall patterns and how they affected Lake Poopó. We found that, as time goes by, the rainy season is getting shorter but more intense. This will is amplifying the cycle of water storage in the lake, with the lake holding less water at the end of the dry season and more at the end of the wet one. It will become even more necessary to regulate resources, for instance by storing water during the wet season to use when it is dry.

Dried shore, boats on lake, hills in distance.
Fishing boats on Lake Poopó back in 2006.
Lovisa Selander / wiki

We found the highest increases in water losses took place in the area around the city of Oruro, which lies to the north of the lake. This is an area with lots of human activity, urban growth, new highways, and where river water has been used for mining and agriculture. Bolivia is the biggest producer of quinoa in the world and the crop increased by 45.5% from 1980 to 2011. As quinoa became more popular around the world over the past decade, production increased a further 60% in just five years to meet global demand.

This all highlights how vulnerable a place such as Lake Poopó can be when relationships between land, human politics and cycles of water and people break apart. The ecological disaster is a consequence of not only natural factors but also human activities – but at least this is one reason there is still hope we can reverse the problem.The Conversation

Juan Torres-Batlló, PhD Candidate, University of Surrey and Belen Marti-Cardona, Lecturer in Earth Observation and Hydrology, University of Surrey

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

Climate Explained: what would happen if we cut down the Amazon rainforest?



Gustavo Frazao

Sebastian Leuzinger, Auckland University of Technology


CC BY-ND

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz


What would happen if we cut down the entire Amazon rainforest? Could it be replaced by an equal amount of reforestation elsewhere?

Removing the entire Amazon rainforest would have myriad consequences, with the most obvious ones possibly not the worst.

Most people will first think of the carbon currently stored in the Amazon, the world’s largest rainforest. But the consequences would be far-reaching for the climate as well as biodiversity and ecosystems — and, ultimately, people.

The overall impact of the Amazon’s complete removal is unthinkable and beyond the power of our current predictive tools. But let’s look at some aspects we can describe.




Read more:
Statistic of the decade: The massive deforestation of the Amazon


Storing carbon, distributing water

The Amazon rainforest is estimated to harbour about 76 billion tonnes of carbon. If all trees were cut down and burned, the forest’s carbon storage capacity would be lost to the atmosphere.

Some of this carbon would be taken up by the oceans, and some by other ecosystems (such as temperate or arctic forests), but no doubt this would exacerbate climate warming. For comparison, humans emit about 10 billion tonnes of carbon every year through the burning of fossil fuels.

But the Amazon forest does more than store carbon. It is also responsible for the circulation of huge quantities of water.

Clouds over the Amazon rainforest.
A uniform layer of tiny ‘popcorn’ clouds covers the Amazon rainforest during the dry season.
NASA/Jeff Schmaltz, CC BY-ND

This image, captured by NASA’s Aqua satellite in 2009, shows how the forest and the atmosphere interact to create a uniform layer of “popcorn” clouds during the dry season. It is during this period, the time without rain, that the forest grows the most.

If the Amazon’s cloud systems and its capacity to recycle water were to be disrupted, the ecosystem would tip over and irreversibly turn into dry savannah very quickly. Estimates of where this tipping point could lie range from 40% deforestation to just 20% loss of forest cover from the Amazon.

Reforestation elsewhere to achieve the same amount of carbon storage is technically possible, but we have neither the time (several hundred years would be needed) nor the land (at least an equivalent surface area would be required).

Another reason why reforestation is not a remedy is that the water the rainforest circulates — and with it the availability of nutrients — would disappear.

Once you cut the circulation of water through (partial) deforestation, there is a point of no return. The water doesn’t disappear from the planet, but certainly from the forest ecosystems, with immediate and powerful consequences for the world’s climate.




Read more:
We found 2˚C of warming will push most tropical rainforests above their safe ‘heat threshold’


Loss of life

Perhaps the most drastic, and least reversible, impact would be the loss of wildlife diversity.

The Amazon hosts an estimated 50,000 plant species — although more recent estimates cite a slightly lower number.

The number of animal species found in the Amazon is even higher, with the largest part made up by insects, representing around 10% of the known insect fauna, as well as a large but unknown number of fungi and microbes.

Once species are lost, they are lost forever, and this would ultimately be the most harmful consequence of cutting down the Amazon. It would possibly be worse than the loss of its role as a massive redistributor and storage of water and carbon.

Last but certainly not least, there are about 30 million people living in and near the Amazon rainforest.

The consequences of losing the forest as a provider of the ecosystem services mentioned above and as a source of food and habitat are unfathomable. The repercussions would reach far into global politics, the global economy, and societal issues.The Conversation

Sebastian Leuzinger, Professor, Auckland University of Technology

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

Coyotes are poised to enter South America for the first time



A photo of a coyote in eastern Panama.
Author provided

Roland Kays, North Carolina State University

The Research Brief is a short take on interesting academic work.

THE BIG IDEA: Coyotes are poised to expand their range to a new continent. The North American canine native has now reached the Darién Gap – a dense wilderness on the border of Colombia and Panama, at the very doorstep of South America. If the coyote succeeds, it would be a new chapter in an amazing evolutionary story that’s played out over the past half century.

WHY IT MATTERS: The historical range of the coyote was originally from western Canada to Mexico. But over the past few decades, it has mixed with wolves and dogs, and its adaptability has allowed the species to expand both east and south, making them commonplace everywhere from New York City to Panama City. My colleagues and I study how humans affect the distribution of wildlife on the planet. Usually this is in a negative way – some endangered species are declining because humans are destroying their habitat or hunting them to near extinction. However, some species are quite good at dealing with the changes people bring to the landscape, and coyotes are an example.

Coyotes are expanding their range. Source: Zoookeys (2018).

WHAT STILL ISN’T KNOWN: If coyotes will actually reach South America, or if jaguars in the Darién will keep them out. Few coyote biologists, including myself, are betting against the coyote. We also don’t know if coyotes, presuming they make it to South America, will have a negative impact on wildlife there. These native species already live with other canine predators in South America, including foxes, so the coyote might not be so bad for native species. People with free-ranging chickens, however, may think that is a different matter!

HOW I DO MY WORK: We set up camera traps, then go back to see what images they captured, and enter everything in a database called eMammal. It’s great to visit a place, see it with your own eyes and speculate about what might be there. Then, a few weeks later, pick up the camera and see all these animals for yourself. Checking the camera memory card is like Christmas every time.

ONE OTHER THING HAPPENING IN THE FIELD: Ricardo Moreno of Yaguara works to save the jaguar in Panama. He is monitoring the Darién to see how the jaguars are doing and working with locals to prevent poaching. He is also running cameras to see if the coyotes move into the Darién.

WHAT’S NEXT FOR YOU: We have just completed #SnapshotUSA, a survey of wildlife across all 50 states, including lots of coyotes! We are in the process of going through the 6 million photos now to identify all the species. We are also working with Wildlife Insights, a data collection site for pictures of wildlife around the world, and Google to develop artificial intelligence to help process all these pictures we get. Maybe this will help us keep an eye on how the coyotes do in Panama.

[ Like what you’ve read? Want more? Sign up for The Conversation’s daily newsletter. ]The Conversation

Roland Kays, Research Associate Professor of Wildlife and Scientist at NC Museum of Natural Sciences, North Carolina State University

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

Amazon Rainfall Crisis


With all of the burning and clearing happening in the Amazon rainforest, it was only going to be a short matter of time before a tipping point was reached and now a tipping point appears on the horizon. It would seem only a matter of 1 or 2 years before the Amazon is unable to sustain itself through rainfall. The link below is to an article reporting on the threat posed to the Amazon.

For more visit:
https://www.theguardian.com/environment/2019/oct/23/amazon-rainforest-close-to-irreversible-tipping-point

The Amazon is on fire – here are 5 things you need to know



Huge fires are raging across multiple regions of the Amazon Basin.
Guaira Maia/ISA

Danilo Ignacio de Urzedo, University of Sydney

Record fires are raging in Brazil’s Amazon rainforest, with more than 2,500 fires currently burning. They are collectively emitting huge amounts of carbon, with smoke plumes visible thousands of kilometres away.

Fires in Brazil increased by 85% in 2019, with more than half in the Amazon region, according to Brazil’s space agency.

This sudden increase is likely down to land degradation: land clearing and farming reduces the availability of water, warms the soil and intensifies drought, combining to make fires more frequent and more fierce.




Read more:
Amazon rainforests that were once fire-proof have become flammable


1. Why the Amazon is burning

The growing number of fires are the result of illegal forest clearning to create land for farming. Fires are set deliberately and spread easily in the dry season.

The desire for new land for cattle farming has been the main driver of deforestation in the Brazilian Amazon since the 1970s.

Ironically, farmers may not need to clear new land to graze cattle. Research has found a significant number of currently degraded and unproductive pastures that could offer new opportunities for livestock.

New technical developments also offer the possibility of transforming extensive cattle ranches into more compact and productive farms – offering the same results while consuming less natural resources.

2. Why the world should care

The devastating loss of biodiversity does not just affect Brazil. The loss of Amazonian vegetation directly reduces rain across South America and other regions of the world.

The planet is losing an important carbon sink, and the fires are directly injecting carbon into the atmosphere. If we can’t stop deforestation in the Amazon, and the associated fires, it raises real questions about our ability to reach the Paris Agreement to slow climate change.

The Brazilian government has set an ambitious target to stop illegal deforestation and restore 4.8 million hectares of degraded Amazonian land by 2030. If these goals are not carefully addressed now, it may not be possible to meaningfully mitigate climate change.

3. What role politics has played

Since 2014, the rate at which Brazil has lost Amazonian forest has expanded by 60%. This is the result of economic crises and the dismantling of Brazilian environmental regulation and ministerial authority since the election of President Jair Bolsonaro in 2018.

Bolsonaro’s political program includes controversial programs that critics claim will threaten both human rights and the environment. One of his first acts as president was to pass ministerial reforms that greatly weakened the Ministry of the Environment




Read more:
Amazon deforestation, already rising, may spike under Bolsonaro


Regulations and programs for conservation and traditional communities’ rights have been threatened by economic lobbying.

Over the last months, Brazil’s government has announced the reduction and extinction of environmental agencies and commissions, including the body responsible for combating deforestation and fires.

4. How the world should react

Although Brazil’s national and state governments are obviously on the front line of Amazon protection, international actors have a key role to play.

International debates and funding, alongside local interventions and responses, have reshaped the way land is used in the tropics. This means any government attempts to further dismantle climate and conservation policies in the Amazon may have significant diplomatic and economic consequences.

For example, trade between the European Union and South American trading blocs that include Brazil is increasingly infused with an environmental agenda. Any commercial barriers to Brazil’s commodities will certainly attract attention: agribusiness is responsible for more than 20% of the country’s GDP.

Brazil’s continued inability to stop deforestation has also reduced international funding for conservation. Norway and Germany, by far the largest donors to the Amazon Fund, have suspended their financial support.

These international commitments and organisations are likely to exert considerable influence over Brazil to maintain existing commitments and agreements, including restoration targets.




Read more:
The world protests as Amazon forests are opened to mining


5. There is a solution

Brazil has already developed a pioneering political framework to stop illegal deforestation in the Amazon. Deforestation peaked in 2004, but dramatically reduced following environmental governance, and supply change interventions aiming to end illegal deforestation.

Environmental laws were passed to develop a national program to protect the Amazon, with clearing rates in the Amazon falling by more than two-thirds between 2004 and 2011.

Moreover, private global agreements like the Amazon Beef and Soy Moratorium, where companies agree not to buy soy or cattle linked to illegal deforestation, have also significantly dropped clearing rates.

We have financial, diplomatic and political tools we know will work to stop the whole-sale clearing of the Amazon, and in turn halt these devastating fires. Now it is time to use them.




Read more:
Huge wildfires in the Arctic and far North send a planetary warning


The Conversation


Danilo Ignacio de Urzedo, PhD candidate, University of Sydney

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

Peace with nature: helping former Colombian guerrilla fighters to become citizen scientists



Ex-combatants learned to survey birds, plants and other wildlife.
Jaime Gongora, Author provided

Jaime Gongora, University of Sydney and Federica Di Palma, Earlham Institute

Colombia is the second most biodiverse country in the world with more than 56,000 recorded species, some 9,000 of which are unique. However protecting and researching this natural treasure has been extraordinarily difficult during Colombia’s nearly 55 years of internal conflict.

Since the 2016 peace agreement 21 scientific bio-expeditions have been carried out, most in areas that were previously conflict zones. This has led to the discovery of more than 150 new animal and plant species.




Read more:
Ecotourism could be making animals less scared, and easier to eat


This flowering of research offers a new opportunity to the thousands of ex-combatants now looking for productive and peaceful work. We worked with former guerrillas in our project GROW-Colombia to train them to protect Colombia’s biodiversity.

Jaime Gongora led workshops with former guerrillas on the promise of biodiversity.
Mario Murcia, Author provided

Who are the ex-combatants?

A huge effort to reincorporate these combatants back into civilian life is under way. Paramount is finding suitable jobs, to rebuild the country and offer stable wages.

A recent census found the former Revolutionary Armed Forces of Colombia (the FARC-EP) consists of some 10,000 people. Ranging between their 20s and 40s, around three-quarters are men.

Around 40% of these ex-guerrillas have experience in environmental conservation, and 70% have agricultural skills. Some 10% would like to work in veterinary, aquaculture and animal production fields, 60% in agriculture, and 84% in terrestrial and river environmental restoration.

There is also increasing interest in ecotourism in the 26 Territorial Training and Reincorporation Spaces (ETCRs) where the ex-combatants are currently based.

Their interests, the new political environment, and nearly 20 tourism initiatives in the ETCRs provide a unique opportunity to promote biodiversity as part of the peace process.

Training ex-combatants to protect biodiversity

We wanted to teach ex-FARC-EP combatants some basic conservation skills and identify the potential of nature to create sustainable business opportunities.

We started with a national workshop with the representatives of 16 ETCRs from across the country. These members reflected on their personal and scientific perceptions of the natural world, mapped ecosystems in their local areas and canvassed ecotourism projects. We then discussed the contributions they made to protecting biodiversity before the peace agreement.

One participant, Curruco* had his own farm before being displaced by the armed conflict. He told us,

our participation in the workshops is evidence of our commitment to peace. We protected the fauna and flora during the conflict.

We then used case studies to teach our workshop members how to take inventory of the species in a given area, explored tourism of nature and conservation in Colombia and discussed business models for the use of biodiversity in ecotourism enterprises.

Some participants explore caves.
Mario Murcia, Author provided

One of the most interesting parts for the ex-combatants was learning techniques for making inventories. We used teaching stations where they learnt about indirect surveys, for example using footprints and faeces, and direct observation and capture. We covered the use of binoculars, trapping cameras, tablets and mobiles, access to taxonomic identification resources and some basic non-invasive sampling methods.

One of the participants, Solangie, had a remarkable knowledge of the Amazon forest. She said:

I enjoyed all the content of the training but I like the bird sightings and plant cataloguing the most because during my time as a combatant we were living among the fauna, including tapirs, reptiles, frogs and butterflies.

I was impressed with the training about plants because in our time in the jungle we used plants as medicine and health treatments.

We then used these skills in practical field work to collect and inventory plants, sight birds and explore caves. The resulting notes and photographs were documented with iNaturalist, an online repository considered a major drawcard in engaging the public in science around the world.

Participants graduated with new knowledge, skills and contacts in research and business.
Jaime Gongora, Author provided

Turning knowledge into business

We also wanted to give our participants a clear idea of how this knowledge could become profitable work. We hosted a business network forum, and 60 meetings were organised so FARC-EP ex-combatants could meet representatives of the major Colombian research institutions and agencies and gain support for their ecotourism and biodiversity initiatives.

Yesenia*, a mother of two, joined FARC at a young age after the paramilitary killed her parents. During the research, she said:

If we want this peace process to succeed it will require the continued involvement of the various components of society, including scientific institutions and universities.

Our work established two levels of organisation: a national biodiversity committee of ETCR representatives from across the country, and a committee of government and non-government institutions and agencies to coordinate and support their biodiversity and ecotourism initiatives.

All of this may sound relatively simple, but this is new and life-changing knowledge for people who were part of an armed conflict, fighting in the jungle against the government.




Read more:
Violence and killings haven’t stopped in Colombia despite landmark peace deal


One of us, Jaime, lived part of his life under this conflict, and found it very moving to see how the climate of trust has been changing. While there are, of course, considerable challenges, this was unimaginable before the peace agreements.


The authors would like to acknowledge the support of the University of Amazonia, Research Institute of Biological Resources Alexander Von Humboldt, Sinchi Amazonic Institute of Scientific Research, COLCIENCIAS-Colombia BIO, United Nations Development Programme, National Natural Parks Colombia, Vice-Ministry of Tourism, Social Economies of the Common, Agency for Reincorporation and Normalisation, Verification Mission of the United Nations, British Embassy in Colombia, ETCR participants, the GROW Colombia team at Earlham Institute, The University of East Anglia and The University of Sydney.The Conversation

Jaime Gongora, Associate Professor, Animal and Wildlife Genetics and Genomics, University of Sydney and Federica Di Palma, Director of Science, Earlham Institute

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

A parasite attack on Darwin’s finches means they’re losing their lovesong



A Small Tree Finch from the Galápagos Islands with an enlarged nostril caused by a parasite.
Katharina J Peters, Author provided

Katharina J. Peters, Flinders University and Sonia Kleindorfer, Flinders University

A parasite known to infect beaks in some iconic Darwin finches on the Galapagos Islands is changing the mating song of male birds.

Our research, published today in Proceedings of the Royal Society B, reveals how the parasite deforms the beak. This has the effect of weakening the male bird’s mating call, and making it no longer clearly distinguishable from that of other closely related species.

A changed song can have an important effect on the male finch’s ability to find a mate.




Read more:
Simply returning rescued wildlife back to the wild may not be in their best interest


It’s another factor that could contribute to declining numbers of these already threatened birds on the Pacific archipelago, about 1,000km off the coast of South America.

A family song to impress

A male finch learns the mating song from his father, and produces the same song for the rest of his life.

It’s a simple tune consisting of one syllable repeated 3 to 15 times, depending on what species of finch he belongs to. Larger-bodied finch species produce a slower song with few syllable repeats, and smaller-bodied finch species produce faster song with many syllable repeats.

Whatever species of finch you belong to, hitting the high notes is important – because females prefer males who can produce such vocally challenging songs.

In the case of the Medium Tree Finch (Camarhynchus pauper), a critically endangered species that only occurs on Floreana Island of the Galapagos Islands, its species-typical song has a bright resonance that rings across the forest canopy.

Medium Tree Finch.
Author provided35.5 KB (download)

An accomplished male singer that can hit the high notes is quickly swooped up by a female looking to pair with a proficient singer.

The ‘Vampire’ parasite

The Vampire Fly – a suggested name for the parasite Philornis downsi given its blood feeding habits from dusk until dawn – was first discovered in a Darwin’s finch nest in 1997.

The parasitic Philornis larvae in a finch nest.
Sonia Kleindorfer, Author provided

Since then, the devastating impacts of its larval feeding habits on nestling birds have been coming to light. The adult fly is vegetarian, but the females lay their eggs into bird nests and their larvae feed on nestling bird beaks from the inside out.

Many Darwin’s finch species now have beaks with massively enlarged nostrils because of damage the feeding fly larvae have caused during the nestling stage. We discovered that a changed beak apparatus measurably affects the song of Darwin’s tree finches with consequences for pairing success.

A Medium Tree Finch male with extremely enlarged nostrils is unable to hit the high notes.

Medium Tree Finch with enlarged nostrils.
Author provided32.2 KB (download)

We found the same pattern in Small Tree Finches (C. parvulus) with enlarged nostrils.

Male finches that produce song with a narrower frequency bandwidth, because their song has a lower maximum frequency, have poor quality song. These males are less likely to be chosen by females, a pattern we documented in both the Medium Tree Finch and the Small Tree Finch.

Also, the song of Medium Tree Finches with enlarged nostrils sounds like the song of the Small Tree Finch.

Small Tree Finches.
Author provided29 KB (download)

When species merge

But confusion among the species and their mating songs may not necessarily be a bad thing for the future survival of individual finches – though it could herald the collapse of species lineages.

Previously, we discovered evidence of hybridisation in Darwin finches. This is where two separate species of finch breed which could potentially produce a new species, phase out one of the species, or cause the collapse of the two existing species into one.

We observed hybridisation driven by female Medium Tree Finches pairing with male Small Tree Finches.

When a female Medium Tree Finch inspects male Small Tree Finches in the forest, she pairs with one who produces high quality song, even if that male is from another species.

A Tree Finch with a normal beak and nostril size, so no infection from the parasite.
Katharina J Peters, Author provided

This female choice seems to be paying dividends, because hybrid pairs with greater genetic diversity also sustained fewer of the parasitic larvae in the nest. And that could lead to fewer birds with infected beaks.




Read more:
Galapagos species are threatened by the very tourists who flock to see them


There are concerted efforts underway to develop control and eradication methods for P. downsi on the Galapagos Islands, building on a collaborative relationship between the Charles Darwin Foundation and the Galapagos National Parks. The Philornis downsi Action Group is an international consortium of concerned scientists working to develop biological control methods.

Our new research is an important step towards understanding how this invasive fly may be changing the evolutionary pathway of Darwin’s finches by literally changing the beak of the finch.The Conversation

Katharina J. Peters, Postdoctoral fellow, Flinders University and Sonia Kleindorfer, Professor of Animal Behaviour, Flinders University

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