Epizoötic Challenges to Pastoral Expansion in Africa: Minding the “Bovine Gap”
15:30 - 17:00
MPI SHH Jena
In two spatiotemporally separate cases in sub-Saharan Africa, small domestic livestock appear around 1000 years before cattle. South of Lake Turkana (eastern Africa), sparse domestic caprines and Lake Turkana ceramics of the Nderit tradition appear c. 4000 BP, nearly 1000 years before the first evidence for cattle. In southern Africa, sheep date to nearly 2200 BP, centuries before evidence for cattle. In 2000, I proposed that African savannas presented novel disease challenges to cattle pastoralism. Sleeping sickness (trypanosomiasis) is a continental-scale risk in brushy areas, but wildebeest-borne malignant catarrhal fever (WD-MCF) and East Coast Fever (ECF) attack cattle in the grasslands that they favor. WD-MCF has a nearly 100% death rate in exposed cattle, and ECF, probably originating with an earlier transmission of Theileria parva from African buffalo to cattle, kills 20% of each cattle cohort. Infection risk is heightened by the three species’ overlapping forage and water requirements. Pastoralists may have exacerbated cattle herds’ vulnerability to infection through anthropogenic savanna expansion. This hypothesis could be falsified by finds of cattle dating to the “Bovine Gap” timespans in either region. As a test, I reviewed 2000-2015 East African archaeofaunal evidence, plus fauna from a stratified site south of Nairobi, GvJm44, yielding Nderit pottery in its lower level. I report these results and discuss how infectious disease genomics might offer finer resolution of routes and times of initial transmission of several wild ungulate diseases to livestock.