- Telegraph op-ed on agricultural biodiversity. Yeah, you read that right.
- No, avocado does not come from the Aztec’s word for testicles. It’s the other way around.
- Why honey is a keeper.
- Mapping the hell out of pigs.
- Photo database to help tell bananas apart.
- Deconstructing the Tragedy of the Commons.
- The C footprint of your diet.
- “We can spare 50 percent and share the rest.”
- Cave man caviar.
- Whiskey with that?
- Potato wild relatives and food security.
- Cassava and food security. No word on its wild relatives.
- Wales finds a new apple.
- Maybe someone will take a cool picture of it.
- Potatoes were always for the masses. Ok, but not sure anyone ever thought otherwise, though.
- Grapes, on the other hand…
- The cuisines of Africa get their shot.
- Some of those will go well with craft beer.
- Agricultural heritage list gets saffron and argan. Bet they go together well.
- Maybe wild kiang tea will get there too someday.
- Or the Aboriginal Australians. Not really agriculturalists, but still.
- Is this alpaca exploitation? Maybe you can take the promotion of agricultural biodiversity too far.
- Will the Svalbard Global Seed Vault qualify one day? Ten years on, still going strong. And return to top.
Tracing environmental history through the fungi and mites of llama poo
By investigating llama poo, a new study just published in the Journal of Archaeological Science by a team from University of Sussex and the Natural History Museum, may not only be shedding light on the collapse of the Inca Empire, but on megafaunal extinctions too. The lead author, Alex Chepstow-Lusty, who has blogged us for us before, has sent us the following. Thanks, Alex, and keep the crap posts coming. Simon Crowhurst, Earth Sciences, Cambridge University drew the cartoon.
It has been said that the triple whammy of guns, germs and steel led to the rapid collapse of the Inca Empire with the arrival of the Spaniards in the 1530s. This was probably the first proper contact between people of the Old World and those of South America for over 10,000 years. As a result, within a few years, the Inca Empire, that stretched from what is today the Colombian border down to the middle of Chile, and might have contained over 10 million people, had dissolved, with a large proportion of the population rapidly succumbing to introduced illnesses. Historical accounts, which started at this time as the Inca probably had no writing, even report that their llamas, which were vital to the economy as sources of wool, transport and dung for fertilizer, contracted diseases and were buried in large pits.
A team from the University of Sussex and the Natural History Museum has been looking at this process in a slightly odd way in a paper that has recently been published in the Journal of Archaeological Science.
As first author Alex Chepstow-Lusty says, “Such a classic catastrophic collapse of both indigenous people and their domesticated animals with the sudden arrival of a destructive new culture would be expected to have made a major impact on the environment. Yet, surprisingly, archaeologists do not have many techniques in their tool box for accurately revealing the changing relationship through time between the numbers of humans and their livestock, whether here in the Andes or elsewhere around the world.”
In recent years, however, a method has been heralded where counts are made of the spores of a fungus called Sporormiella that grows on large herbivore excrement. Deposited in the layers of sediments, particularly of lakes, the abundance of these dispersed, well-preserved spores has been used to provide a history of livestock in the landscape, and even supposedly reveal the extinction of megafauna in different parts of the world. However, unlike megafaunal extinctions which might be linked to climate change, the collapse of the Inca was indisputably caused by the arrival of Europeans in Peru a little less than 500 years ago, but the details of it have never been tested using Sporormiella spores.
As co-author, Michael Frogley says “There have been an increasing number of dissenting studies that question whether Sporormiella fungal spores are really telling the true story of large herbivores on the landscape: one of the problems being that the spores are dispersed only short distances of a few metres close to the ground, attaching themselves in glutinous little packets to the vegetation, subsequently eaten by livestock during grazing and appearing again with the excrement in which they germinate if the conditions are right. But most of the sites investigated are large lakes. Just how do the spores get deposited in the centres of these large lakes where the sediment cores are extracted from? And that is why other techniques need to be used to check these results.”
So, the team investigated a little lake — more of a deep pond really — called Marcacocha, close to Cuzco, the religious and administrative heart of the Inca Empire. At the height of the Empire, caravan trains of up to a thousand llamas using a nearby trading route would stop at the lake to graze on the surrounding pasture.
Also found in the lake sediment layers with Sporormiella spores were oribatid mites (relatives of spiders). Across a period spanning the last 1200 years, the abundances of both spores and mites were compared in the sediment layers: the Sporormiella spores are around 40 times smaller than the oribatids, which themselves are only about 0.5 mm in length.
As co-author Anne Baker of the Natural History Museum notes “Aquatic oribatid mites belonging to the genus Hydrozetes were most common. Their numbers clearly traced the rise and rapid collapse of the Inca Empire, as reflected in changes in size of the passing llama caravans. Hydrozetes even showed a peak when the Spaniards introduced their animals from the Old World, like cows, horses and sheep, and a dip when these animals disappeared because there was no-one to care for them after smallpox arrived around 1719 and killed nearly all the surviving indigenous people in the area.”
“Changing food supply is a strong candidate for causing the fluctuations in numbers. These mites feed on decomposing plants, which could have included dung ending up in the lake from the llamas and later from the introduced livestock. Also, the mites might have responded to differing amounts of dung and urine draining into or being deposited in the water over time.”
However, as Alex Chepstow-Lusty observed “Sporomiella spores bizarrely showed no such signal as Hydrozetes — only showing high abundances when lake levels were already low and they were washed in with other material, or when the lake filled up with mud, and subsequently deposited peat. This allowed animals to graze and defecate close to the centre of the lake, with the spores of the fungus only having to travel a short distance.”
“This shows that this technique may be a blunt instrument, and rather gives information about animals getting closer to the centre of the lake to defecate, rather about animal numbers themselves.”
And as Michael Frogley continues, “Sporormiella is a bit like Goldilocks. The fungus will only grow on the excrement if it is not too dry or not too wet, but has just the right amount of moisture. Getting these ideal conditions may be a bit of a problem for achieving its reproductive cycle.”
“We should also not forget that llamas defecate communally, and that the excrement, which is called llama beans, is a vital part of the Andean economy when dried, providing one of the best fertilizers in the world, and is much valued at high altitudes for cooking and heating where trees are thin on the ground.”
As Anne Baker concludes, “Mites are useful in archaeological analyses because their ecology evidently has not changed through history, so, by identifying them, we can get a picture of conditions when they were alive. More, however, still needs to be known about the identity of fossil mites and the ecology of modern ones. We have looked at one small lake in Peru, but the technique we have used does appear very promising and could be applicable elsewhere.”
Brainfood: Distribution modelling, New mycorrhiza, Bean diversity, Collecting, Intensification, Wildish rice, Wild tomato genome, Conservation prioritization, Horizon scanning, Maize domestication, Livestock sustainability, Asexual rice
- Incorporating knowledge uncertainty into species distribution modelling. Not sure about this.
- A mycorrhizal revolution. “Fine root endophytes are arbuscule-forming fungi unexpectedly placed in Mucoromycotina.” Wow. I think.
- Genetic Diversity within Snap Beans and Their Relation to Dry Beans. Snap beans came from dry beans, but maybe more than once and from both Andean and Mesoamerican genepools, and now they make up 8 genepools.
- Two decades of evolutionary changes in Brassica rapa in response to fluctuations in precipitation and severe drought. It matters when you collect germplasm.
- Agricultural intensification, dietary diversity, and markets in the global food security narrative. What if it’s intensification through diversification, though? Didn’t think of that, did you?
- Seed characteristic variations and genetic structure of wild Zizania latifolia along a latitudinal gradient in China: implications for neo-domestication as a grain crop. Crop wild relative that is also a crop might be a good candidate to become another crop.
- The Genome Sequence of the Wild Tomato Solanum pimpinellifolium Provides Insights Into Salinity Tolerance. It’s all in the inositol pathway.
- Not all data are equal: Influence of data type and amount in spatial conservation prioritisation. Follow the money. Ok, to unpack that, read this.
- A Horizon Scan of Emerging Issues for Global Conservation in 2019. Biotechnological advances in crop breeding may impact insects and land use.
- Multiproxy evidence highlights a complex evolutionary legacy of maize in South America. Linguistics, archaeology and genetics say maize left Mexico semi-domesticated, was finished off and diversified in Amazonia.
- Assessing the Role of Cattle in Sustainable Food Systems. They still have one.
- A male-expressed rice embryogenic trigger redirected for asexual propagation through seeds. Clonal propagation of hybrids. What could possibly go wrong?
The maize two-step
Isn’t it great that you can get a bite-sized digest of the latest thinking about maize domestication from the horse’s mouth, via Twitter?
Brainfood: Global taro, Gender gap, Eschatology, Cacao domestication double, Soybean epigenetics, Rice domestication, Domestication space, Botanic gardens, Agrarian care, Open seeds, Sustainable nutrition, Broadbean breeding, Resistant beans, Yam environments, Trade networks
- Conserving and Sharing Taro Genetic Resources for the Benefit of Global Taro Cultivation: A Core Contribution of the Centre for Pacific Crops and Trees. The first line of defence against Taro Leaf Blight, among other things.
- Female access to fertile land and other inputs in Zambia: why women get lower yields. Because they’re stuck with the poorer soils. I’m assuming there was some control for maize variety, but the damn thing is behind a paywall. LATER: Yeah, they controlled for hybrid vs open pollinated variety.
- Towards a dialogue of sustainable agriculture and end-times theology in the United States: insights from the historical ecology of nineteenth century millennial communes. In other news, it has become necessary to reconcile the apocalypse with sustainability.
- Population genomic analyses of the chocolate tree, Theobroma cacao L., provide insights into its domestication process. Domestication was both good and bad.
- The use and domestication of Theobroma cacao during the mid-Holocene in the upper Amazon. Archaeology says domestication in western Amazon in line with above (somewhere in Ecuador?), but earlier than thought.
- DNA methylation footprints during soybean domestication and improvement. Differentially methylated regions are particularly genetically diverse.
- Major domestication-related phenotypes in indica rice are due to loss of miRNA-mediated laccase silencing. Not so much the genes, as their regulation.
- Phylogenetic patterns and phenotypic profiles of the species of plants and mammals farmed for food. Plants and animals are different.
- Botanic Gardens Complement Agricultural Gene Bank in Collecting and Conserving Plant Genetic Diversity. 6000 taxa in 68 crop genera are in botanic gardens. Check out the rest of the special edition of Biopreservation and Biobanking on agricultural genebanks.
- Plants: Crop diversity pre‐breeding technologies as agrarian care co‐opted? Pre-breeding ignores farmers’ knowledge.
- The Open Source Seed Licence: A novel approach to safeguarding access to plant germplasm. Seeds will find a way.
- When too much isn’t enough: Does current food production meet global nutritional needs? No: grow more food and vegetables.
- Breeding and genomics status in faba bean (Vicia faba). Plenty of diversity to be still used. Pass the chianti.
- QTL Mapping of Resistance to Bean Weevil in Common Bean. Based on a cross between the susceptible Zambian landrace Solwezi and the resistant breeding line AO-1012-29-3-3A. But which Solwezi? I hope there’s a DOI in the actual paper for those who get through the paywall.
- Spatial Multivariate Cluster Analysis for Defining Target Population of Environments in West Africa for Yam Breeding. 7 mega-environments identified, but what I want to know is if any are under-represented in terms of material in the genebank.
- Economic shifts in agricultural production and trade due to climate change. Under mitigation scenarios trade networks for agricultural commodities get more distributed, and possibly therefore more stable. So that’s another reason to mitigate C emissions, you know, apart from saving the planet.