Early agriculture in the Old and New Worlds

Last week saw the publication of a couple of papers about early agriculture in two very different regions which will probably have people talking for quite a while. From Snir et al. 1 came a study of pre-Neolithic cultivation in the Near East. And from the other side of the world, there was the latest in the controversy over the extent of Amazonian agriculture from Clement et al. 2.

Yes, I did say pre-Neolithic. The key finding of the archaeological work described by the first paper is that 23,000 years ago, or over 11 millennia before the putative start of agriculture in the Fertile Crescent, hunter-gatherers along the Sea of Galilee in what is now Israel maintained little — and, crucially, weedy — fields of cereals. The archaeobotanists found remains of both the weeds and the cereals at a site called Ohalo II, as well as of sickles, and the cereals were not entirely “wild”, as the key domestication indicator of a non-brittle rachis was much more common than it should have been. To see what this means, have a look at this diagram from a fairly recent paper on agricultural origins in the region. 3

diagram

Those “first phenotypic indications of domestication”, dated at 12,500 years ago, need to be pushed quite a bit leftwards on that timeline now, off the edge in fact. A non-shattering rachis, it seems, was quite a quick trick for wild grasses to learn. But the process by which they acquired all the other traits that made them “domesticated” was very protracted and stop-start.

Zoom over to Amazonia, and the transition to farming took place much later, probably around 4,000 years ago, according to the other paper published last week. But it was just as significant as in the much better-known “cradle of agriculture” in the Fertile Crescent, with perhaps 80 species showing evidence of some domestication. The difference, of course, is that Amazonian agriculture was based on trees, rather than annual grasses and legumes.

amazon clement

According to the authors, parts of the Amazon basin, in particular those now showing evidence of earthworks and dark, anthropogenic soils, were just as much managed landscapes by the time of European contact as the places those Europeans came from. But compare our collections of crop diversity from the Amazon basin (courtesy of Genesys, which admittedly does not yet include Brazilian genebanks)…

amazon

with what we have from the Near East…

fertile crescent

If we want to know more about how the domestication process and transition to agriculture differed in the Amazon and the Fertile Crescent, there’s a whole lot of exploration still to do.

Nibbles: High science, Methane-friendly rice, Gender, Indian priestesses, Banana extinction, Inka legacy, Diversity in ag, Yerba genome, Cucumber chains, Tomato relative, Agrobiodiversity in art

Brainfood: Grassland diversity, Potato diversity, English CWR, Genetic rescue, Saffron diversity, Lac, Cereal domestication, Turkish pea, Pathogen genomes, Rose fragrance, African cheese

Brainfood: Domestication stats, Apple vulnerability, Himalayan fermentation, Tree diversity, Grasslands double, Shiitake cultivation, Lablab core, Ethiopian sweet potato, Georgian grape

Invisible Angola

Kew botanist David Goyder had a thought-provoking blog post a couple of days back describing the relative lack of floristic data from Angola. Here’s his map of plant collection data for southern Africa, from GBIF:

GBIF Angola_2015_6a

Angola emerges quite clearly as a gap, particularly the interior. There’s lots of reasons for that, not least landmines, as Goyder points out, and there are also efforts underway to redress the situation. But the thought that the map provoked in me was, of course, whether the situation was similar for crops. So here’s what Genesys knows about crop germaplasm collections in southern Africa:

Angola genesys

It seems the answer is a pretty resounding yes. Again, you can clearly trace the borders of Angola by where the genebank accessions end. There is, in fact, though, a very active national genebank in Angola, which has been collecting the country’s crop diversity for years, landmines or no landmines:

A total of 441 accessions were collected during a mult-crop collection in Huila province, Namibi province and Malanga province in 2004. With these collections, NPGRC now has a representative sample from 55% of the total number of districts in the country and representing 60% of the recognized agricultural zones (MIIA).

But when will we be able to see the data?