Human Genetic Bottleneck: When Only 1,280 Humans Were Left

In 2023, a study in the journal Science suggested that our ancestors may have dropped to about 1,280 breeding adults roughly 930,000 years ago, and stayed that low for over 100,000 years. That's a human genetic bottleneck so severe we'd have nearly gone extinct. But was it real? Puck travels back to find out why our DNA looks so strangely similar, what could have nearly wiped us out, why archaeologists and many geneticists aren't convinced, and why the real story might be about one very lucky group. If only 1,280 humans were left on Earth today, who would you want in your group? Tell me in the comments. CHAPTERS 0:00 Meet Puck, 930,000 years ago 1:00 The weird thing about your DNA 1:42 The jellybean problem 2:16 What is a genetic bottleneck? 2:35 The study: only 1,280 ancestors? 3:51 What could cause it? Ice ages and drought 4:36 The rocks disagree 5:31 The twist: one lucky group 6:21 Out of Africa: a bottleneck nobody died in 6:48 The humans who really vanished 7:21 So, did we almost go extinct? SOURCES Main study: Hu, W. et al. (2023). Genomic inference of a severe human bottleneck during the Early to Middle Pleistocene transition. Science 381(6661), 979–984. DOI: 10.1126/science.abq7487 Critique and context: Ashton, N. & Stringer, C. (2023). Did our ancestors nearly die out? Science 381(6661), 947–948. DOI: 10.1126/science.adj9484 Expert reactions (Stephan Schiffels, Pontus Skoglund, Aylwyn Scally and others) reported by Science and AFP, August to September 2023. Deng, Y., Nielsen, R. & Song, Y. S. (2025). A previously reported bottleneck in human ancestry 900 kya is likely a statistical artifact. Genetics 229(1), iyae192. DOI: 10.1093/genetics/iyae192 Cousins, T. & Durvasula, A. (2025). Insufficient evidence for a severe bottleneck in humans during the Early to Middle Pleistocene transition. Molecular Biology and Evolution 42(2), msaf041. DOI: 10.1093/molbev/msaf041 Genetic diversity of chimpanzees and other great apes: Prado-Martinez, J. et al. (2013). Great ape genetic diversity and population history. Nature 499, 471–475. DOI: 10.1038/nature12228 Oldest genomes of our species (Ranis and Zlatý kůň, no known descendants): Sümer, A. P. et al. (2025). Earliest modern human genomes constrain timing of Neanderthal admixture. Nature 638, 711–717. DOI: 10.1038/s41586-024-08420-x To read any of these, search the title or DOI in Google Scholar. A note on accuracy: the 1,280 figure is one study's estimate and is still debated. The video presents it as a hypothesis, not a settled fact. #humanevolution #ancienthumans #genetics