Recurrant collection of Drosophila melanogaster from wild African environments and genomic insights into species history

• A long-standing enigma concerns the geographic and ecological origins of the intensively studied vinegar fly, Drosophilamelanogaster. This globally distributed human commensal is thought to originate from sub-Saharan Africa, yet untilrecently, it had never been reported from undisturbed wilderness environments that could reflect its precommensalniche. Here, we document the collection of 288 D. melanogaster individuals from multiple African wilderness areas inZambia, Zimbabwe, and Namibia. The presence of D. melanogaster in these remote woodland environments is consistentwith an ancestral range in southern-central Africa, as opposed to equatorial regions. After sequencing the genomes of 17wilderness-collected flies collected from Kafue National Park in Zambia, we found reduced genetic diversity relative totown populations, elevated chromosomal inversion frequencies, and strong differences at specific genes including knowninsecticide targets. Combining these genomes with existing data, we probed the history of this species’ geographicexpansion. Demographic estimates indicated that expansion from southern-central Africa began 10,000 years ago,with a Saharan crossing soon after, but expansion from the Middle East into Europe did not begin until roughly 1,400years ago. This improved model of demographic history will provide an important resource for future evolutionary andgenomic studies of this key model organism. Our findings add context to the history of D. melanogaster, while openingthe door for future studies on the biological basis of adaptation to human environments.

Subject headings

NATURVETENSKAP  -- Biologi -- Biokemi och molekylärbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Biochemistry and Molecular Biology (hsv//eng)

NATURVETENSKAP  -- Biologi -- Genetik (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Genetics (hsv//eng)

Keyword

Population genomics

Drosophila

Africa

demographic history

commensal evolution

wilderness collection

Publication and Content Type

art (subject category)

ref (subject category)