Yesterday’s Brainfood included the paper “Genetic diversity evolution of a sheep breed reintroduced after extinction: Tracing back Christopher Columbus’ first imported sheep,” which sounds intriguing enough from the title and abstract to piss off a lot of our readers for the rest being behind a paywall. Actually, though, it’s on ResearchGate. But it’s a long read, so here’s the short version, which also draws from an article in FAO’s newsletter Animal Genetic Resources Information dating back to 2000.
Before being conquered by the Spaniards in the late 15th century, the Canary Islands were home to non-wooly (i.e. hairy) sheep. This is surprising because nearby Northwest Africa has had mostly wooly sheep from 4000–3000 BC. Hairy sheep are adapted to humid tropical conditions and are more prevalent in sub-Saharan Africa. They may have been taken to the Canaries between 3000–2000 BC by the first inhabitants of the islands during an episode of northern expansion during a period of more favourable climate.
From the Canaries, they were taken to the Caribbean, starting with Columbus’ second journey, and thereafter spread through the Americas. There, they were crossed with other hairy breeds brought from sub-Saharan Africa with the slave trade. Meanwhile, they eventually went extinct back in the Canary Islands, due to cross-breeding with more productive sheep, and changes in the agricultural system as a result of Spanish colonization.
In the 1950’s, however, hairy sheep were re-introduced into the Canaries from Venezuela. The resulting current population of Canary Hair Sheep seems to have fairly high diversity, high census and effective population sizes, and satisfactory numbers of newborn animals registered per year. It thus seems to be a good example of successful “recreation” (or as near as one can figure it) of an extinct breed.
- Land‐use history determines ecosystem services and conservation value in tropical agroforestry. Not all agroforests are created equal.
- Temperate agroforestry systems provide greater pollination service than monoculture. No word on land-use history though.
- Machine learning for high-throughput field phenotyping and image processing provides insight into the association of above and below-ground traits in cassava (Manihot esculenta Crantz). Fancy maths helps you estimate root yield from drone images of the canopy of cassava plots.
- A dynastic elite in monumental Neolithic society. Ancient DNA suggests Atlantic megaliths were built to honour incestuous god-kings. But n=1, so there’s that.
- Keeping pace with climate change in global terrestrial protected areas. The representation of climates in protected areas is going to change, with cold and warm climates suffering.
- Network analysis of regional livestock trade in West Africa. It all starts in Burkina Faso.
- Gender and Trait Preferences for Banana Cultivation and Use in Sub-Saharan Africa: A Literature Review. Farmers still prefer traditional cultivars.
- Decoding diversity in the food system: wheat and bread in North America. “Although the dominant trends are toward uniformity, there are also numerous forms of resistance.” Banana farmers available for comment.
- Against the Grain: Long-Term Patterns in Agricultural Production in Prehistoric Cyprus. There was resistance during the agricultural transition too.
- Legacy of Amazonian Dark Earth soils on forest structure and species composition. Forest that was actively managed and farmed in pre-Columbian times is more diverse.
- Evidence of genetic diversity within Solanum Lycopersicum L. ‘Platense’ landrace and identification of various subpopulations. The accessions thus labelled in an Argentinian genebank show a lot of variation.
- Genetic diversity evolution of a sheep breed reintroduced after extinction: Tracing back Christopher Columbus’ first imported sheep. Decolonization in action.
- Simple rules for concise scientific writing. Easier said than done, as all the above confirm.
I downloaded the cultivated wheat data from Genesys and imported everything into QGIS to play around with. That’s almost 5,000 genebank accessions, about half of which are geo-referenced. Here’s the result.
Circles are all cultivated wheats, red dots everything that is not bread wheat. Note the irrigated areas (dark blue) are more likely to have modern varieties, and that the area of rainfed cultivation (bright green) varies considerably from year to year with precipitation. Probably some more collecting to be done then, in particular in the rainfed northwestern region, based on this map. But I’m not going to bet on that until I see whereVIR’s 570-odd Afghan wheats were collected.