Bushfire in Madagascar: natural hazard, useful tool, and change agent

Bushfire does not usually figure on lists of natural hazards in Madagascar, despite being damaging hazard on the island. This chapter argues that the lack of attention to fire comes from the fact that fire is multivalent, ambiguous, and flexible, being simultaneously an occasional 'hazard' for thatch-roof huts or crop fields, a 'useful tool' that farmers and pastoralists use to manage vegetation, and a major transformational force, or 'change agent', that damages land and forest. The chapter builds on the concept of pyric phases, identifying six important pyric phases in which fire serves, or is perceived to serve, different roles as hazard, tool, or change agent

Genomic landscape of human diversity across Madagascar

International audienceAlthough situated ∼400 km from the east coast of Africa, Madagascar exhibits cultural, linguistic, and genetic traits from both Southeast Asia and Eastern Africa. The settlement history remains contentious; we therefore used a grid-based approach to sample at high resolution the genomic diversity (including maternal lineages, paternal lineages, and genome-wide data) across 257 villages and 2,704 Malagasy individuals. We find a common Bantu and Austronesian descent for all Malagasy individuals with a limited paternal contribution from Europe and the Middle East. Admixture and demographic growth happened recently, suggesting a rapid settlement of Madagascar during the last millennium. However, the distribution of African and Asian ancestry across the island reveals that the admixture was sex biased and happened heterogeneously across Madagascar, suggesting independent colonization of Madagascar from Africa and Asia rather than settlement by an already admixed population. In addition, there are geographic influences on the present genomic diversity, independent of the admixture, showing that a few centuries is sufficient to produce detectable genetic structure in human populations