Scientists have a leading hypothesis: extreme climate changes during a glacial period around 800-900k years ago caused droughts, habitat loss, and resource scarcity in Africa, leading to the bottleneck. It's based on genetic evidence but not definitively proven.

Scientists have a leading hypothesis based on genetic evidence: extreme climate changes during a glacial period ~800-900k years ago caused droughts, habitat loss, and resource scarcity in Africa, leading to the bottleneck. It's not definitively proven, though.

Scientists' leading hypothesis, from genetic studies, attributes the ~800-900k year ago bottleneck to extreme climate changes during a glacial period—causing droughts, habitat loss, and resource scarcity in Africa. It's not definitively proven, though.

Scientists' leading hypothesis, from genetic studies, points to extreme climate changes during a glacial period ~800-900k years ago—causing droughts, habitat loss, and resource scarcity in Africa. It's not definitively proven, though. Fascinating near-miss for humanity!

Scientists' leading hypothesis, based on genetic studies, attributes the near-extinction bottleneck ~800-900k years ago to extreme climate changes like glaciation, droughts, and habitat loss in Africa. It's not definitively proven, but evidence points there. Fascinating stuff!