Quinoa, the ancient grain- from subsistence to cash crop

Quinoa is a herbaceous plant native to the Central and Northern region of the Andes in South America. This plant was domesticated by the Incas inhabiting the region approximately 5,000 to 3,000 years BCE. This highly valued crop by the Incas, however, was forbidden by Spanish colonisers that intended to substitute quinoa with potatoes, wheat and barley. The Incas challenged this prohibition and maintained quinoa in hidden locations risking having their hands cut off or being killed. Hence, It is due to the resilience of the Incas and their descendants, the Quechua and Aymara indigenous communities, that quinoa has made it to our days (Small 2013).

Despite being a highly appreciated crop by indigenous communities in the Andean regions of Bolivia, Peru, Chile and Ecuador, for most of the post-colonial history of these countries, quinoa was considered as “Indian food” inappropriate for consumption by the elites (Walsh-Dilley 2020). 

It was not until the 1980s that the richer North Hemisphere countries grew interested in this nutritious crop. It was then when Indigenous communities in the Bolivian Altiplano (Andean region) began commercialising this crop outside the country via fair-trade routes as an organically certified product. The commercialisation via these ethical routes ensured that the market price of quinoa covered the costs of production in the Bolivian Altiplano (Walsh-Dilley 2020). 

The popularity of this pseudo-grain continued growing in the 2000s as consumers in the richer North were keen on finding healthier and gluten-free alternatives to other common grains such as wheat and barley. Quinoa appeared as the alternative that consumers were looking for and its demand increased rapidly. The market prices of this ancient grain skyrocketed as a consequence and after 2008 prices doubled and tripled the previous years marking what is known as the “quinoa boom” (Walsh-Dilley 2020). 

Quinoa was not only attractive for its nutritional value but also for its ability to grow in harsh environments with extreme temperatures, very low precipitation and with soils containing high levels of salt and low levels of nutrients. Quinoa was seen as an ideal crop that could alleviate food insecurity worldwide while enduring extreme weather conditions due to climate change. In this context, the Food and Agriculture Organisation (FAO) of the United Nations declared 2013 as the International Year of Quinoa (Bazile, Jacobsen, and Verniau 2016).

The growing interest in quinoa as well as the surge in prices was positively perceived by the traditionally poor and marginalised indigenous community in the Bolivian Altiplano. At last, they had the chance to improve their economic situation and quality of life. But an ancient pseudo-grain traditionally grown as a subsistence crop became a cash crop. Quinoa consumption decreased amongst the indigenous populations and was substituted by other less nutritious grains such as rice and wheat (Jacobsen 2011). If you were a quinoa producer, it was worth selling your production, if you were not, the high prices made it a luxury product that you could not afford.

The high quinoa market prices also attracted producers outside the Bolivian Andes. In Peru, where quinoa had been traditionally cultivated by indigenous peasants in the Andean region, the state invested in expanding quinoa cultivation to other parts of the country. In addition to this, quinoa was no longer produced with traditional methods. Quinoa farmers in Peru used chemical inputs such as fertilisers and pesticides and even sometimes used irrigation to obtain a greater yield (Walsh-Dilley 2020). In 2015, Peru became the greatest exporter of quinoa and the greatest competitor of indigenous communities in the Bolivian Altiplano.

In 2015, the higher availability of quinoa lead to a drastic and unpredicted drop of its market price (Figure above). Quinoa was no longer a fair trade and organically certified product with market prices linked to the production costs in the Bolivian Altiplano. This unexpected price drop, in combination with a period of unusual drought experienced in the Altiplano between 2015 and 2017 attributed to climate change, rendered Bolivian peasants in a very vulnerable situation. Why?

Before we arrive to any conclusion about good and evil, let’s explore how Bolivian indigenous communities arrived to this situation. To do this, we need to first understand two concepts: Resilience and Political Ecology and how they can complement each other based on Quandt (2016).

Resilience – is understood as the ability of a system (or community in this specific case) to absorb disturbance (price drop and drought) while maintaining its function and structure. The aim of resilience management is to provide sustainability of the economy, society and natural resources of a specific system. When a system is subject to disturbances that alter its normal functioning and structure, the system undergoes an adaptive cycle that allows it to exploit the new circumstances for growth. Hence, the system will not return to its initial state but will regenerate and reorganise into a new state.

Political ecology – is a multi-disciplinary framework that prioritises politics and power dynamics to understand the relationship between human populations and the environment and how these are connected to environmental degradation. It also pays special attention to the historical context to understand the use of natural resources and environmental degradation.

Resilience thinking applies ecological concepts to study society and it has been criticised for not considering the role of important social aspects such as power and culture in the adaptive cycle of a system. Contrarywise, political ecology has been criticised for being mainly focused on power dynamics and politics. Thus, for these and other reasons, integrating these two concepts can bring a deeper understanding of political, economic, social and environmental changes within a system and can help us to reconstruct altered systems to return to a state of equilibrium. 

Thence, to understand how Bolivian peasants arrived to this vulnerable situation it is necessary to have a political ecology of resilience perspective as Marygold Walsh-Dilley states in her brilliant paper “Resilience compromised: Producing vulnerability to climate and market among quinoa producers in Southwestern Bolivia”. By historicising we can understand the factors that left the Altiplano indigenous community with no ability to adapt to climate change (drought) and market vagaries (quinoa price drop). Historical neglect and marginalisation of these indigenous communities is undeniably an important factor leading to vulnerability however I won´t consider this specific factor for this blog post. 

To better understand the factors leading this community to a vulnerable stage we first need to understand the particularity of the Bolivian Altiplano ecosystem and how quinoa was traditionally cultivated in this area. 

The Altiplano region of Bolivia is a high plateau located at 3,600 to 4,100 m above sea level and surrounded by the Andes mountain range. This region is characterised by having fresh water and saltwater lakes as well as salt deserts such as the Salar de Uyuni and Salar de Coipasa (Picture below)**. The Bolivian Altiplano is subjected to extreme climate conditions with temperatures ranging from -11°C to 30°C and with annual rainfall ranging from 140 to 250 mm (to compare, London annual’s rainfall is 621 mm and Dundee (Scotland) is 673 mm). In addition to this, the soil where plants grow is very poor in nutrients and has high levels of salt, making it impossible to grow most crops. 

**The formation of these lakes and deserts is very interesting but this explanation would make this blog post too long. So, if you are interested in knowing more about the formation of these lakes and deserts leave a message at the bottom of the post or send me a private message.

Traditionally, quinoa cultivation has been done manually with long periods of fallow during which the farmland dedicated to quinoa is left uncultivated. This traditional technique helps the soil to recover its nutrients and moisture. Fallow periods are of particular importance for the Altiplano region due to the low level of soil nutrients and annual rainfall. Additionally, llama husbandry has also played an important role in quinoa farming by providing an additional source of nutrients to the soil with their manure (Jacobsen 2011).

Before quinoa seeds are planted, fields are prepared by clearing wild vegetation and tilling the soil before the rainy season arrives in January. The soil is left fallow to absorb rain water until October-November when quinoa seeds are planted. The moisture accumulated during this first rainy season allows the seeds to germinate and start growing. The second rainy season, on the following January, provides sufficient water for the quinoa to continue growing until May when it is harvested before winter frost. Hence, one growing season of quinoa requires the moisture of two rainy seasons (Jacobsen 2011). 

Picture credit  Bioversity International/A. Camacho

Then, how did quinoa farmers become so vulnerable? The following arguments are based on Walsh-Dilley (2020)

When quinoa started to be commercialised, farmers in the Altiplano were organised in cooperatives and shared tasks and machinery. Tractors were purchased by cooperatives and so belonged to the community rather than to a specific farmer. Prices in quinoa from the 2000s raised drastically and brought economic prosperity to the farmer communities in the Bolivian Altiplano. 

The economic benefits from quinoa commercialisation during the quinoa “boom”, together with the access to cash through bank credits shifted the organisation of the communities from collective to individualistic. Farmers shifted towards neoliberal livelihood with little between farmer collaboration, individualistic investments for instance by buying their own tractors and abandonment of cooperatives and associations that contributed to initiate quinoa commercialisation. Cooperatives and associations were rendered weaker and inadvertently, these indigenous communities became weaker as well. A weaken community would be revealed when unable to respond to the unexpected market price drop in 2015 and a remarkably dry period between 2015 and 2017.

In ecological terms, the Altiplano ecosystem is delicate due to the extreme weather conditions experienced and the type of soil with high levels of salt and low levels of nutrients. Quinoa cultivation in this particular ecosystem requires fallow periods to collect sufficient water and to help the soil recover its nutrients. The presence of llama husbandry is also required to provide an external source of nutrients for the soil. 

Due to the high demand of quinoa, farmers reduced fallow periods from 2-6 years to 1-2 years. Additionally, quinoa farmers expanded the production area in the Altiplano by 300% between 1975 and 2010 displacing llama pasture elsewhere (Walsh-Dilley 2020). As a consequence, the soil could not recover the nutrients and the water necessary for quinoa cultivation and could not benefit from llama’s manure any longer. As a result of reduced soil quality quinoa yield per farmed area decreased over time (Jacobsen 2011, 2012; Winkel et al. 2012).

When the quinoa price dropped in 2015 and the Altiplano experienced severe drought, the farmers found themselves between a rock and a hard place. Climate change and market vagaries revealed a weaken community unable to react in front of adverse circumstances. On the one hand, soil water content and fertility was reduced due to a reduction in fallow periods and llama pasturing. Longer fallow periods were necessary to restore soil quality. The drought experienced between 2015 and 2017 further hindered quinoa production. On the other hand, cooperatives and associations were weak and unable to organise a solution. Farmers were also in debt with the banks and needed to pay back their bank credits obtained during the more prosperous period. Hence, despite the negative impact on the already debilitated ecosystem in the Altiplano farmers were compelled to continue growing quinoa deepening the crisis by a continuous ecosystem degradation.

Resilience is the capacity of a community to resist stressors and continue functioning. Thence, these Andean communities need to recover their resilience in order to confront future climate and market vagaries. I wanted to mention some measures that in my opinion can help these indigenous communities to recover their sovereignty. However, I would like to clarify that these are not necessarily the only solutions. 

Protected Origin Denomination – The possibility of creating a Protected Origin Denomination for the Bolivian quinoa variety Quinoa Real considered of greater quality is being discussed. This type of certification would guarantee the quality of Bolivian quinoa that could be purchased as a premium quality at higher prices. 

In an interview lead by Bolivian journalist Miriam Telma Jemio to Jorge Fernández the president of the Andean Valley Corporation, a company that has been producing and exporting quinoa for more than 20 years (1). (Translated from Spanish by Pilar Morera Margarit).

The first step is to achieve a Protected Origin Denomination, a certificate that legally protects food products from some geographic areas and prevents other producers from taking advantage of this reputation. This would allow to explain that this variety (Quinoa Real) contains 11 of the most important amino acids for human nutrition, low fat content and no cholesterol, reasons by which it has become a gourmet product.

Miriam Telma Jemio, Bolivian journalist

Unfortunately, this (the nutritious content of quinoa) is only known by few people. We, Bolivians, have failed to promote the benefits and qualities of the organic Quinoa Real from Bolivia. The Protected Origin Denomination has remained inactive for 12 years. This needs to be worked at a State level, otherwise we do not have a way of showing the world that our quinoa is different.

Jorge Fernández, president of Andean Valley Coorporation

Quinoa adapted tractors – Technological development is also required to create tractors adapted to quinoa farming and to the delicate ecosystem of the Altiplano region (Jacobsen 2011). In the same interview mentioned above, Jorge Fernández highlights this technological gap.

There is not a single machine developed for our quinoa producers and there is not a single Bolivian institution leading this technological development

Jorge Fernández, president of Andean Valley Coorporation

Land management rules – Introduction and enforcement of land management rules that prevent ecosystem degradation. The village of San Juan, where the research conducted by Walsh-Dilley (2020) was focussed, in 2014 detailed a series of “norms” based on traditional fallow periods. These set of rules included sufficiently long fallow periods as well as the conservation of native flora between quinoa farmland. However, these rules were not enforced and were abandoned when the quinoa prices raised.

Empowering women – Quinoa has also the potential of empowering indigenous women. In a project funded by the Spanish Agency for International Cooperation for the Development (AECID), with the local partners Ecuadorian Cooperation Fund for the Development (FECD) and the institution ASCENDER indigenous women from the Ecuadorian Andes were trained in the process of farming quinoa (2).

They have provided us with workshops and courses to teach u show to produce natural manure and to use equipment.

Ana Lucía Cucuri, indigenous woman from the Nutiluisa community in the Palmira region of Ecuador

Economic compensation for sharing plant genetic resources – The signing of the Convention on Biological Diversity in Rio de Janeiro, Brazil, in 1992 established national sovereignty over biodiversity obliging countries to arrive to bilateral agreements for the exchange of genetic resources. However, before 1992, when the Convention on Biological Diversity was established, 25 countries were already in possession of quinoa collections outside the Andean countries and these are distributed without the need for legal actions or the agreement with the countries of origin (Bazile et al. 2016).

In 2004 the International Treaty on Plant Genetic Resources for Food and Agriculture became legally binding. This treaty aimed at establishing a global system for sharing plant genetic resources between farmers, plant breeders and scientists. Additionally, the treaty aimed at ensuring that economic benefits obtained from the use of genetic resources are shared with the countries of origin. However, the treaty only considers 64 of the considered the most important crops, excluding quinoa (3). 

As a result, the quinoa genetic heritage salvaged by the Incas from the Spanish colonisers and kept in the tradition of indigenous Andean communities is being exploited worldwide without providing any economic compensation to the indigenous communities. 

Thus, measures such as creating a brand of “Bolivian Quinoa Real” sold as a gourmet product, establishing norms for reducing ecosystem degradation, empowering indigenous women traditionally marginalised, and Including quinoa as part of the International Treaty on Plant Genetic Resources for Food and Agriculture as well as acknowledging the role of these indigenous communities in preserving quinoa genetic diversity would bring economic inputs that could be invested in recovering resilience.

Further reading and references:
Bazile, Didier, Sven-Erik Jacobsen, and Alexis Verniau. 2016. “The Global Expansion of Quinoa: Trends and Limits.” Frontiers in Plant Science 7. doi: 10.3389/fpls.2016.00622.
Jacobsen, S. E. 2011. “The Situation for Quinoa and Its Production in Southern Bolivia: From Economic Success to Environmental Disaster.” Journal of Agronomy and Crop Science 197(5):390–99. doi: https://doi.org/10.1111/j.1439-037X.2011.00475.x.
Jacobsen, S. E. 2012. “What Is Wrong With the Sustainability of Quinoa Production in Southern Bolivia – A Reply to Winkel et al. (2012).” Journal of Agronomy and Crop Science 198(4):320–23. doi: https://doi.org/10.1111/j.1439-037X.2012.00511.x.
Quandt, Amy. 2016. “Towards Integrating Political Ecology into Resilience-Based Management.” Resources5(4):31. doi: 10.3390/resources5040031.
Small, Ernest. 2013. “42. Quinoa – Is the United Nations’ Featured Crop of 2013 Bad for Biodiversity?” Biodiversity 14(3):169–79. doi: 10.1080/14888386.2013.835551.
Walsh-Dilley, Marygold. 2020. “Resilience Compromised: Producing Vulnerability to Climate and Market among Quinoa Producers in Southwestern Bolivia.” Global Environmental Change 65:102165. doi: 10.1016/j.gloenvcha.2020.102165.
Winkel, T., H. D. Bertero, P. Bommel, J. Bourliaud, M. Chevarría Lazo, G. Cortes, P. Gasselin, S. Geerts, R. Joffre, F. Léger, B. Martinez Avisa, S. Rambal, G. Rivière, M. Tichit, J. F. Tourrand, A. Vassas Toral, J. J. Vacher, and M. Vieira Pak. 2012. “The Sustainability of Quinoa Production in Southern Bolivia: From Misrepresentations to Questionable Solutions. Comments on Jacobsen (2011, J. Agron. Crop Sci. 197: 390–399).” Journal of Agronomy and Crop Science 198(4):314–19. doi: https://doi.org/10.1111/j.1439-037X.2012.00506.x.
1. Interview Miriam Telma Jemio. https://dialogochino.net/en/agriculture/26442-bolivian-quinoa-producers-place-hope-in-china/
2. Project to empower Ecuadorian indigenous women. https://www.efeagro.com/noticia/quinoa-cereal-ecuador/
3. International Treaty on Plant Genetic Resources for Food and Agriculture http://www.fao.org/plant-treaty/areas-of-work/the-multilateral-system/overview/en/

The Medieval climate change or climate anomaly

Since the beginning of industrialisation in the 18th century humans have been burning fossil fuels and releasing large quantities of greenhouse gases* into the atmosphere. These gases have saturated the natural cycles that maintain a stable atmospheric composition, leading to an over-accumulation of greenhouse gases. 
Normally, Solar radiation enters the atmosphere and arrives to the Earth’s surface, where it is partially absorbed and partially re-emitted back to the atmosphere. This re-emitted radiation is then partially returned to the Earth’s surface while the rest escapes to space. A higher level of atmospheric greenhouse gases behaves as a thick barrier that reduces the amount of Solar radiation that escapes the atmosphere. As a consequence, a bigger proportion of radiation is returned back to the Earth’s surface increasing the radiation absorbed and hence the planet’s temperature (Image below). 
The over-accumulation of greenhouse gases due to human activities has resulted in the increase of temperature globally, commonly known as global warming, and this has affected our planet’s climate. 

Image from Giant clams blog (1).

To better understand what we refer to when we talk about climate change we need first to understand the difference between weather and climate.

Meteorologists refer to weather as the atmospheric conditions that we experience in our daily life. Weather would be having a rainy or a sunny day, for example. However, climate refers to long-term trends in weather. Mediterranean climate, for instance, is that experienced in the Mediterranean basin with its characteristic hot and dry summers and mild and rainier winters. When we talk about climate change, we are talking about global changes in average temperature, rainfall, sea surface temperature and ice sheets extension.

Climate change, of course, is not a phenomenon exclusive from our present. The Earth has experienced various climate change events during its long existence. The difference with the current climate change is that while those occurred naturally, this one is being induced by human activities.
I find particularly fascinating a period of climate change that occurred during the Medieval ages dating approximately from 800-1300 and named the Medieval Climate Anomaly (MCA). During this period of time, North European regions experienced warmer and wetter weather conditions while South European and North African regions experienced colder winters and drier conditions. Historically, It is thought that these benign weather conditions in Northern regions enabled Vikings to venture to Greenland and Iceland (Easterbrook, 2016).
The spatial scale of this climate change remains a matter of debate amongst the scientific community. While some scientists defend the MCA was a global climate change event, others defend it was a more localised event. For this blog post I will only consider how this phenomenon affected the climate in Europe and North Africa. 

To understand what caused the climate change during the Medieval ages we need to understand what is a climate oscillation.

Climate is influenced by the atmosphere, the biosphere (sum of all ecosystems), the oceans and the cryosphere (Earth surface where the water is frozen). These climate variables influence each other causing regular changes in temperature, rainfall, sea temperature, etc. These regular changes, or fluctuations, determine what we refer to as a climate oscillation. Climate oscillations have phases and each of the phases are recognised for having characteristic values of these climate variables. For instance, a well-known climate oscillation is the El Niño Southern Oscillation (ENSO) which directly affects temperature and rainfall in the areas surrounding the Pacific ocean. The most reported phase of this oscillation in the news is usually the El Niño as it is responsible for extreme weather conditions and devastating effects in the American continent and the west Pacific islands Indonesia, Malaysia, the Philippines and northern Australia.

European climate is largely influenced by a climate oscillation known as the North Atlantic Oscillation (NAO). This oscillation consists of two large and interconnected masses of air situated north and south respect to each other. The northern air mass has higher pressure and locates around Iceland, whereas the southern air mass has lower pressure and locates around the Azores islands. The difference in pressure between these two air masses determines the intensity of air spinning between them. The greater the pressure difference the stronger the air spinning.
This climate oscillation has two phases, a positive and a negative phase. The NAO phases oscillate often but the persistence of a single phase does not normally exceed more than a few months.
Positive phase – When the NAO oscillation is in the positive phase, the pressure difference between the two areas increases and North European regions experience warmer and wetter weather. Contrarywise, regions in the South of Europe and the North of Africa experience colder and drier weather conditions. 
Negative phase – When the NAO oscillation is in the negative phase, the pressure difference between these areas is smaller and North European regions experience colder and drier conditions while regions in the South of Europe and the North of Africa experience wetter and warmer conditions.

How can scientists determine the climate in the past?
Paleoclimatologists search for clues to infer past climates by collecting data that like a window to the past can reveal the weather experienced many years ago. These clues can be for instance tree-ring and cave formations or speleothems.
Tree-rings – Trees make a new layer of bark every year and so the number of rings on a tree, or tree-rings, tell us the age of a tree. Tree growth is affected by the atmospheric conditions experienced each year. In a warmer and wetter year trees will grow a thicker ring than in colder or drier years. This is how, by studying tree-ring thickness scientists can determine the atmospheric conditions at different points in time.

Image from Flickr Creative Commons user Amanda Tromley.

Speleothems – Cave formations or speleothems, such as stalactites and stalagmites, can also be used by scientists to determine atmospheric conditions experienced in the past. Speleothems are formed when water carrying minerals enters a cave and drops, slowly depositing these minerals. After a long period of time, this slow mineral deposition will form stalactites and stalagmites. As the deposition of minerals and growth of speleothems is directly related to the amount of water entering a cave, it is a good indicator of the atmospheric conditions experienced in the past. 

What caused the Medieval Climate Anomaly?
A group of scientists (Trouet et al., 2009) collected data on tree-rings in Morocco and speleothems in Scotland to unravel the weather conditions experienced during the MCA. Altogether, Scottish speleothems suggested this was a period of warmer and wetter weather, while Moroccan tree-rings suggested this was a period of colder and drier weather. These weather conditions were then determined to be caused by the NAO oscillation in positive phase. The particularity of the MCA, though, was that this NAO positive phase was stabilised for a prolonged period of time of approximately 500 years, whereas it normally lasts for only few months. What stabilised the NAO in positive phase during such long time?

Glamis Castle, Angus, Scotland

To understand what stabilised the NAO in positive phase we first need to understand what is the El Niño Southern Oscillation (ENSO). 

The El Niño Southern Oscillation (ENSO) is a climate oscillation that affects areas on the Pacific ocean. In a neutral state, ENSO brings warm water from the east of the Pacific ocean towards the west. This warm water accumulates in the Indonesian side and its evaporation induces high levels of precipitation in that region. 
The ENSO, similarly to the NAO, has two phases: El Niño and La Niña. During La Niña phase, these conditions are intensified and the Indonesian side is even warmer and wetter while the American side colder and drier as a consequence. Coincidently, this October (2020) La Niña phase was officially declared by the Pacific Meteorological Desk Partnership (1) and it is currently having devastating effects in Philippines (2).

Volcanoes can have a direct effect on the climate due to their influence on the Solar radiation. Volcanoes emit dust that reflects Solar radiation and prevents it from reaching the Earth’s surface. Consequently, volcanoes have the opposite effect to the greenhouse gases as Solar radiation reaching the Earth’s surface decreases and with it the planet’s temperature. Contrarywise, lower volcanic activity enables more Solar radiation from reaching the Earth’s surface increasing the planets temperature.

The MCA was a period with marked low volcanic activity and high Solar radiation (1) (Image below). The higher level of Solar radiation reaching the Earth’s surface contributed to increasing the temperature on the western equatorial Pacific ocean. This raise in temperature influenced the ENSO that fluctuated to La Niña phase. The continuous reduced volcanic activity during the MCA contributed to stabilise La Niña phase for a prolonged period of time. Climate oscillations are interconnected globally via atmospheric and oceanic currents. A stable La Niña phase then influenced the NAO to be stabilised in positive phase during a long period of time and causing the climate change experienced during the MCA in Europe and North Africa.

An event of such scale clearly demonstrates that climate, unlike governments, does not care about borders.

Image from Friedhelm Steinhilber and Jürg Beer (2011). Solar activity – the past 1200 years. PAGES news, Vol 19, No 1. (http://www.pages.unibe.ch/download/docs/newsletter/2011-1/NL2011-1_lowres.pdf)

To understand the text you may need the following concept:
*What are greenhouse gases?
Greenhouse gas is any gas that has the property of absorbing infrared radiation (net heat energy) emitted from Earth’s surface and reradiating it back to Earth’s surface, thus contributing to the greenhouse effect. Carbon dioxide, methane, and water vapour are the most important greenhouse gases (5).

*Note for the readers
If you want to know more about this topic or if you are interested in reading about another topic please write me a message below so I can prepare the next post/s.

1. Giant clams blog. https://blogs.ntu.edu.sg/hp3203-2017-23/
2. La Niña officially declared by the Pacific Meteorological Desk Partnership. https://reliefweb.int/report/cook-islands/la-ni-officially-declared-pacific.
3. Devastating effects of La Niña in Philippines. https://www.aljazeera.com/news/2020/10/26/philippines-typhoon-molave-displaces-thousands-floods-villages.
4. Friedhelm Steinhilber and Jürg Beer (2011). Solar activity – the past 1200 years. PAGES news, Vol 19, No 1. http://www.pages.unibe.ch/download/docs/newsletter/2011-1/NL2011-1_lowres.pdf).
5. Greenhouse gases. https://www.britannica.com.
Easterbrook D.J. (2016) Chapter 21 – Using Patterns of Recurring Climate Cycles to Predict Future Climate Changes, In Evidence-Based Climate Science (Second Edition), pp. 395–411. Ed D. J. Easterbrook. Elsevier.
Trouet V., Esper J., Graham N.E., Baker A., Scourse J.D., Frank D.C. (2009) Persistent Positive North Atlantic Oscillation Mode Dominated the Medieval Climate Anomaly. Science, 324, 78–80.

Why do we see colours?

Our vision is responsible for perceiving colours and shapes in our environment. This is possible because of a special type of cells present in the eye retina* named cone cells. These cells contain pigments that absorb light at different wavelengths of the luminous spectrum. In simple terms, these pigments can sense different colours. The presence of different cone cells with different pigments is what supports colour vision. The greater the diversity of pigments, the more colours will be perceived. When the light interacts with the cone cells, these will transmit an electric signal to the brain. The brain will combine the information from all the different cells to construct a detailed picture of the outside world.

Colour vision in vertebrates* evolved 540 Mya in an early ancestor. This vertebrate ancestor carried four types of cone cells and therefore four types of pigments. These prehistoric cone cells were able to perceive light in the red, green, blue and violet or ultraviolet spectra. This type of colour vision is referred to as tetra-chromatic because the four different pigments enable the perception of four different colours. Vertebrates that evolved from this early ancestor, such as fish, birds and reptiles, therefore also possess tetra-chromatic vision. Diurnal* fish that live in shallow waters and are exposed to light, for example salmon, still have the ability to distinguish four colours. Similarly, modern-day reptiles and birds, such as crocodiles or sparrows, also have tetra-chromatic vision. 

Mammals evolved from reptiles approximately 200 Mya in an era dominated by the most famous reptiles, the dinosaurs. In order to avoid predation, scientists believe that our mammalian ancestors were nocturnal and hid during the day. In the darkness of the night there was no need for colour perception. Thus, early mammals must have had tetra-chromatic vision but over time two of the four pigments degenerated. Consequently, mammals lost their ability of distinguishing four colours and their vision became di-chromatic. This is why the great majority of modern-day mammals, such as our beloved cats and dogs, can only see two colours. 

Dinosaurs extinguished 65 Mya and so the lower predatory pressure permitted mammals to expand their habitats and acquire diurnal* habits. During that time, primates evolved an extra pigment which enabled them to distinguish blue green and red. These primates therefore had tri-chromatic vision. Scientists believe that the evolution of tri-chromatic vision in primates allowed them to detect ripe fruits and suitable leaves to eat. Just as the other primates, most humans can distinguish three colours: blue green and red. However, there are exceptions to this rule. In capuchin monkeys, for instance, only the females have tri-chromatic vision. In humans, not being able to distinguish three colours is called “colour blindness” or “colour vision deficiency”. This is quite common and occurs in 8% of men and 0.5% of women in the world.

Why do we have a mixture of di- and tri-chromatic vision in some primates?

Primates are social animals and live in groups. It is believed that tri-chromatic vision in some female primates makes them better at locating areas with ripe fruits and edible leaves. These females can then lead the rest of the group towards the food source. Di-chromatic individuals, on the other hand, are better at distinguishing patterns and hence quicker at detecting predators with camouflage patterns. These individuals may be responsible for raising the alarm to alert the rest of the group. Therefore, in a social context, having a mixed group of individuals with both tri- and di-chromatic vision may be more beneficial than a group with uniform vision.

Could it be possible that the same is true for humans? Maybe “colour blind” individuals in pre-historic times were responsible for detecting approaching predators, thus protecting the group.

To understand the text you might need the following concepts:

What is the retina?
Is a region of the eye normally located at the outermost layer ocular globe. This region contains the cells responsible from sensing the light from the outside. It also connects these cells with the neurons that will transmit the information to the visual areas of the brain.(1)

What are vertebrates?
Vertebrates are a subphylum of animals that include jawless fish, jawed vertebrates, tetrapods (reptiles, amphibians, birds and mammals) and fish with bones. They are characterised for having a back bone amongst other features.(2) 

What are diurnal animals?
Diurnal animals are those that remain active during the day and are inactive or sleeping durin thte night. 

Further reading and references:

  1. https://www.britannica.com/science/retina
  2. https://www.britannica.com/animal/vertebrate

Borges, Rui, Warren E. Johnson, Stephen J. O’Brien, Cidália Gomes, Christopher P. Heesy, and Agostinho Antunes. 2018. “Adaptive Genomic Evolution of Opsins Reveals That Early Mammals Flourished in Nocturnal Environments.” BMC Genomics 19(1):121.
Bowmaker, James K. 1998. “Evolution of Colour Vision in Vertebrates.” Eye 12(3):541–47.
Carvalho, Livia S., Daniel M. A. Pessoa, Jessica K. Mountford, Wayne I. L. Davies, and David M. Hunt. 2017. “The Genetic and Evolutionary Drives behind Primate Color Vision.” Frontiers in Ecology and Evolution 5.
Jacobs, Gerald H. 2009. “Evolution of Colour Vision in Mammals.” Philosophical Transactions of the Royal Society B: Biological Sciences 364(1531):2957–67.
Lucas, Peter W., Nathaniel J. Dominy, Pablo Riba‐Hernandez, Kathryn E. Stoner, Nayuta Yamashita, Esteban Lorí- Calderön, Wanda Petersen‐Pereira, Yahaira Rojas‐DurÁN, Ruth Salas‐Pena, Silvia Solis‐Madrigal, Daniel Osorio, and Brian W. Darvell. 2003. “Evolution and Function of Routine Trichromatic Vision in Primates.” Evolution 57(11):2636–43.
Saito, Atsuko, Akichika Mikami, Takayuki Hosokawa, and Toshikazu Hasegawa. 2006. “Advantage of Dichromats over Trichromats in Discrimination of Color-Camouflaged Stimuli in Humans.” Perceptual and Motor Skills 102(1):3–12.

Coconut, a tasty testimony of human globalisation

The coconut palm, Cocos nucifera, is a tropical plant that produces coconuts as a way of reproduction and dispersion towards new areas. Coconuts have the peculiarity of being able to float in sea water. This ability allows coconuts to reach surrounding areas and islands where they germinate and grow into new palms.
The coconut palm is a common crop cultivated across tropical countries. Coconuts are used for food and drink purposes as well as a source of oil, charcoal and fibre worldwide. But, did coconuts spread through all these countries transported by the sea? A genetic study on coconut palms has shown that this is not the case. Coconut palm global expansion is, rather, a result of human movements and trade routes that date from pre-Columbian era.

The coconut palm originated on the Pacific and Indian ocean basins where humans began to cultivate it separately in each of these regions. Over time, the separated cultivation of this plant gave rise to two coconut palm sub-populations with distinctive features, named the Pacific and Indian sub-populations. The distinctiveness of both sub-populations can be observed in the shape of the fruit or the height of the palm but also on the genes. These genetic footprints, together with other anthropological evidences, have allowed scientists to trace the routes by which this plant species acquired its pantropical distribution (Figure below).
The Pacific coconut palm sub-population originated in Southeast Asia and had its main cultivation centres from the Malay peninsula to New Guinea. This sub-population spread towards the east expanding to eastern Polynesia. Interestingly, this sub-population reached the Pacific coast of Latin America 2,250 years ago, likely carried by pre-Columbian Austronesian* seafarers from the Philippines (Figure below). 
The population originating on the Indian ocean was cultivated around 2,500-3,000 years ago with its main cultivation centres in the southern periphery of India including the islands of Sri Lanka, Maldives and Laccadives (Figure below). We have for example historical records that show  the use of coconut in ancient Ayurvedic medicine texts. 
The Indian sub-population initially dominated the Indian ocean basin area. However, the Pacific sub-population was brought into this region, as well as in the east coast of Africa, first through Austronesian trade routes and later through Arab trade routes (Figure below). Archaeobotanical records from the Tanzanian Pemba island for instance demonstrate the importance of coconuts from the 700 to the 1,500 CE in the food culture.
The Indian sub-population, meanwhile, remained confined to the Indian ocean basin. But later on, during European colonial era, its expansion range was extended. Portuguese colonisers brought this coconut palm sub-population to West Africa, Brazil and the Caribbean. In Mexico, instead, only the Pacific sub-population is present which is likely related to Spanish colonisers importing plants from Solomon Islands (Figure below).

But why was this plant carried around for cultivation? It Is likely that it enabled the establishment of maritim trade routes by providing a way of transporting food but also importantly drinking water.
So, next time you sprinkle some coconut on a cake, use coconut fibre on your potted plants or wear coconut jewelery, think that this plant is a living witness of human globalisation history.

Figure taken from: Gunn, Bee F., Luc Baudouin, and Kenneth M. Olsen. 2011. “Independent Origins of Cultivated Coconut (Cocos Nucifera L.) in the Old World Tropics”. PLoS ONE 6(6):e21143.

To understand the text you may need the following concepts:
Who are the Austronesians?
The people that inhabited the areas of remote Oceania and were Austronesian speakers. This people came from a prehistoric migration from Taiwan around 3,000 to 1,500 BCE and concluded the last stage of Neolithic human expansion.(1)

Further reading and references:
Gunn, Bee F., Luc Baudouin, and Kenneth M. Olsen. 2011. “Independent Origins of Cultivated Coconut (Cocos Nucifera L.) in the Old World Tropics” edited by P. K. Ingvarsson. PLoS ONE 6(6):e21143.
(1) Chang, C.S., Liu, H.L., Moncada, X., Seelenfreund, A., Seelenfreund, D. and Chung, K.F., 2015. A holistic picture of Austronesian migrations revealed by phylogeography of Pacific paper mulberry. Proceedings of the National Academy of Sciences112(44), pp.13537-13542. 

How do plants sense the spring?

When spring arrives, plants start to sprout and soon delight us with their colourful flowers and pleasant scents. But how do plants know that it is time to bloom? 

Plants have a biological clock, also known as the circadian clock, which coordinates key physiological processes that occur throughout the day and through the seasons. Such processes include petal opening, leaf movement or flowering time. This biological clock is by default determined internally. However, its rhythm is modified by external signals such as light and temperature. In this way, plants are able to set the clock time to the environment in response to external cues. By doing that, plants can, for example, adapt to the lengthening of days from winter to summer.

There is not only one circadian clock in every plant but a multitude of them that need to be synchronised to ensure the correct growth, development and reproduction of the plant as a whole. At the tiniest level, each cell* within the plant has its own clock. These cellular clocks are synchronised at a tissue* level, which constitutes the association of cells with similar functionalities. Plant organs*, such as leaves, shoots and roots, are each formed by different tissues themselves. So, all the tissues within an organ are also synchronised. As each plant organ fulfils a different role within the plant, the clock of each organ will display different sensitivities to the various environmental cues. For instance, light will strongly influence leaves, whose major function is to transform the light into energy via photosynthesis*. Roots, however, will be less affected by light, as their major function is to absorb water and nutrients from the soil. All organ clocks will be synchronised between themselves but also with the ecosystem that is inhabited by the plant. For instance, many plants rely on pollinators* for their reproduction. Hence, plants will coordinate their flowering time and production of scents to attract pollinators when these are more active, for example in spring. 

This is why, when temperature rises and days are getting longer, we can admire the beauty of daffodils, snow drops and hyacinths that once again wave us with their joyful colours and fragrant smells.

To understand the text you may need the following concepts:
What is a cell?
Cells are the building blocks of all living organisms. If we would compare a multi-cellular organism to a house, cells would be the bricks.(1)
What is a tissue?
Tissues are, in multi-cellular organisms, the organisation level constituted by groups of cells with similar structure and function. If we would compare a multi-cellular organism to a house, we would consider as separate tissues the walls, floors and ceilings.(2)
What is an organ?
Organs are the next level of organisation above the tissue level. These are composed of different tissues and have a specific function within the multi-cellular organism. If we would compare a multi-cellular organism to a house, an organ would be each of the rooms which has a specific function, for example the kitchen for cooking or the bedroom for sleeping.(3)
What is photosynthesis?
Photosynthesis is the process by which plants and other organisms use light to produce energy. As a consequence plants take up CO2 from the atmosphere and secret oxygen. Hence, we recognise plants as very important in fighting climate change.(4)
What are pollinators?
Pollinators are animals, like the well-known bees, that aid plants to reproduce. They visit flowers attracted by their colours and scent. When pollinators visit flowers, pollen grains attach to their surface. Pollen are male reproductive cells of plants that need to be transported to other flowers for reproduction. So, when the same pollinator visits another flower, the pollen grains carried on its surface will be deposited and will fertilise the female part of the visited flower. (5)

References and further reading:
– Greenwood, Mark, and James CW Locke. 2020. “The Circadian Clock Coordinates Plant Development through Specificity at the Tissue and Cellular Level.” Current Opinion in Plant Biology 53:65–72.
– McClung, C. Robertson. 2006. “Plant Circadian Rhythms.” The Plant Cell 18(4):792–803.
1. https://www.nature.com/scitable/topicpage/what-is-a-cell-14023083/
2. https://www.britannica.com/science/tissue
3. https://www.britannica.com/science/organ-biology
4. https://www.livescience.com/51720-photosynthesis.html
5. https://ento.psu.edu/pollinators/resources-and-outreach/what-are-pollinators-and-why-do-we-need-them

Ants as caterpillar farmers

Ants are fascinating social insects with recognised farming abilities. This has recently been shown in the interaction between the ant species Camponotus compressus and the gram blue lycaenid* butterfly Euchrysops cnejus while coexisting on the cowpea plant Vigna unguiculate. Upon detection of butterfly larvae*, ants construct a shelter at the base of the plant. Larvae, when ready to pupate*, move down from the plant to the shelter where they will stay until reaching adulthood and becoming butterflies. During this period, ants attend pupae and may play an important role in protecting them against natural enemies. Meanwhile, ants benefit from the sugary secretions produced by the pupa. Here, nature presents us with another beautiful example of mutualism* between these two insect species. 
This information has been obtained from the following Research article. For more detailed information please refer to it.
A single lycaenid caterpillar gets an ant-constructed shelter and uninterrupted ant attendance by Priya Aradhya Ekka & Neelkamal Rastogi. Entomologia Experimentalis et Applicata (2019).

To understand the text you may need the following concepts:
*What is mutualism? Mutualism is a type of ecological interaction between individuals of different species in which all the organisms involved obtain a net benefit.(1)
*What is a lycaenid butterfly? These are butterflies that belong to the family Lycaenidae, the second-largest family of butterflies.(2)
*What is a butterfly larva and pupa? The butterfly life cycle encompasses different developmental stages which progress from egg to larva, pupa until adult butterfly.
The initial developmental stage is the egg from which a larva, also known as caterpillar for moths and butterflies, emerges. This larva is the feeding stage as it will solely eat to grow and store nutrients. Once the larva is fully grown, it enters the following phase known as pupation. Pupae, also named chrysalis in the case of butterflies, will remain quiet while the whole body changes structure to become an adult butterfly, process known as metamorphosis. The adult butterfly will then reproduce and lay new eggs closing the life cycle.(3)

  1. J.N. Holland, J.L. Bronstein, in Encyclopedia of Ecology, 2008
  2. Pierce, N. et al. “The Ecology and Evolution of Ant Association in the Lycaenidae (Lepidoptera)” ( 2002). Annual Review of Entomology 47 (1): 259-267
  3. The Academy of Natural Sciences of Drexel University (https://ansp.org/exhibits/online-exhibits/butterflies/lifecycle/)