Map sources. All maps were made with data from Natural Earth (http://www.naturalearthdata.com/).
Figure 1. Contours in panel (a) are based on Fig. 2A of L. L. Cavalli-Sforza, P. Menozzi, and A. Piazza, “Demic Expansions and Human Evolution,” Science 259 (1993): 639–46. Contours in panel (b) are based on interpolation of the numbers shown in Fig. 3 of W. Haak et al., “Massive Migration from the Steppe Was a Source for Indo-European Languages in Europe,” Nature 522 (2015): 207–11. The interpolation was performed using the POPSutilities.R software of F. Jay et al., “Forecasting Changes in Population Genetic Structure of Alpine Plants in Response to Global Warming, Molecular Ecology (2012): 2354–68 and the parameter settings recommended in O. François, “Running Structure-like Population Genetic Analyses with R,” June 2016, http://membres-timc.imag.fr/Olivier.Francois/tutoRstructure.pdf.
Figure 2. The plot shows the 3,748 unique individuals in the author’s internal laboratory database as of November 19, 2017, broken down by the year when they became available.
Figure 4. The number of genealogical ancestors expected to have contributed DNA to a person living today is based on simulation results shared with the author by Graham Coop. The simulations were performed as described in G. Coop, “How Many Genetic Ancestors Do I Have,” gcbias blog, November 11, 2013, https://gcbias.org/2013/11/11/how-does-your-number-of-genetic-ancestors-grow-back-over-time/.
Figure 5. The number of mutations in a given segment that separate the genome a person receives from his or her father and the one he or she receives from his or her mother can be used to estimate how much time has elapsed since the common ancestor at that location in the genome. Panel (2), which is based on the analyses reported in S. Mallick et al., “The Simons Genome Diversity Project: 300 Genomes from 142 Diverse Populations,” Nature 538 (2016): 201–6, shows the estimated times since the most recent shared ancestor averaged across 250 non-African genome pairs (solid line), and 44 sub-Saharan African genome pairs, measured at equally spaced locations in the DNA. Panel (3) shows the maximum estimated time at each location in the genome over 299 genome pairs and is based on analyses from the same study.
Figure 6. The approximate range of the Neanderthals is adapted from Fig. 1 of J. Krause et al., “Neanderthals in Central Asia and Siberia,” Nature 449 (2007): 902–4.
Figure 7. The counts of shared mutations are based on the French-San-Neanderthal comparison in Table S48 of the Supplementary Online Materials of R. E. Green et al., “A Draft Sequence of the Neandertal Genome,” Science 328 (2010): 710–22.
Figure 8. The illustration is based on the data in Fig. 2 of Q. Fu et al., “An Early Modern Human from Romania with a Recent Neanderthal Ancestor,” Nature 524 (2015): 216–19.
Figure 9. This illustration replots the data shown in Fig. 2. of Q. Fu et al., “The Genetic History of Ice Age Europe,” Nature 534 (2016): 200–5.
Figure 10. The pie chart data come from columns AJ and AK of Supplementary Table 2 of S. Mallick et al., “The Simons Genome Diversity Project: 300 Genomes from 142 Diverse Populations,” Nature 538 (2016): 201–6. Each population is represented by an average of the individuals in that population. The proportion of archaic ancestry is expressed as a fraction of the maximum seen in any population in the dataset. Numbers less than 0.03 are set to 0 and numbers greater than 0.97 are set to 1. A subset of 47 populations is plotted to highlight the geographic coverage while reducing visual clutter.
Figure 13. This illustration represents the migrations in Europe described in Q. Fu et al., “The Genetic History of Ice Age Europe,” Nature 534 (2016): 200–5. The ice extent is redrawn based on an online figure in “Extent of Ice Sheets in Europe,” Map. Encyclopaedia Britannica Online, https://www.britannica.com/place/Scandinavian-Ice-Sheet?oasmId=54573.
Figure 14. Panel (a) is redrawn based on Extended Data Fig. 4 of W. Haak et al., “Massive Migration from the Steppe Was a Source for Indo-European Languages in Europe,” Nature 522 (2015): 207–11. Panel (b) and its inset are adapted with permission from Fig. 1 and Fig. 2 of D. W. Anthony and D. Ringe, “The Indo-European Homeland from Linguistic and Archaeological Perspectives,” Annual Review of Linguistics 1 (2015): 199–219.
Figure 15. The scatterplots in all three panels are based on the principal component analysis shown in Fig. 1b of I. Lazaridis et al., “Genetic Origins of the Minoans and Mycenaeans,” Nature 548 (2017): 214–8. The x- and y-axes are rotated to roughly align genetic and geographic positions.
Figure 16. The pie charts are based on 180 Bell Beaker individuals for which there is enough ancient DNA data to make relatively precise estimates of steppe-related ancestry. The individuals are grouped by country within present-day Europe. The data are from a revised version of I. Olalde et al., “The Beaker Phenomenon and the Genomic Transformation of Northwest Europe,” bioRxiv (2017): doi.org/10.1101/135962.
Figure 17. In panel (a), the South Asian Language family contours are redrawn based on a plot in A Historical Atlas of South Asia, ed. Joseph E. Schwartzberg (Oxford: Oxford University Press, 1992). In panel (b), the scatterplot is based on the principal component analysis in Fig. 3 of D. Reich et al., “Reconstructing Indian Population History,” Nature 461 (2009): 489–94. The x- and y-axes are rotated to roughly align genetic and geographic positions.
Figure 18. The geographic contours and estimated dates for the spread of wheat and barley agriculture are drawn based on a sketch kindly provided by Dorian Fuller. The contours for the western half of the map follow Fig. 2 of F. Silva and M. Vander Linden, “Amplitude of Travelling Front as Inferred From 14C Predicts Levels of Genetic Admixture Among European Early Farmers,” Scientific Reports 7 (2017): 11985.
Figure 19. The North American ice sheet and shoreline positions are derived from the figures on pages 380–83 of A. S. Dyke, “An Outline of North American Deglaciation with Emphasis on Central and Northern Canada,” Quaternary Glaciations—Extent and Chronology, Part II: North America, ed. Jürgen Ehlers and Philip L. Gibbard (Amsterdam: Elsevier, 2004), 373–422. The Eurasian ice sheet positions are derived from Fig. 4 of H. Patton et al., “Deglaciation of the Eurasian Ice Sheet Complex,” Quaternary Science Reviews 169 (2017): 148–72. The South American ice and shoreline positions are derived form Fig. 5.1 of D. J. Meltzer, “The Origins, Antiquity and Dispersal of the First Americans,” in The Human Past, 4th Edition, ed. Chris Scarre (London: Thames and Hudson, expected early 2018), 149–71. The ancient Siberian shoreline is interpolated.
Figure 20. This illustration combines information from Fig. 2 of D. Reich et al., “Reconstructing Native American Population History,” Nature 488 (2012): 370–74 and Fig. 5 of P. Flegontov et al., “Paleo-Eskimo Genetic Legacy Across North America,” bioRxiv (2017): doi.org/10.1101/203018.
Figure 21. This illustration replots the data from Fig. 1 of P. Skoglund et al., “Genetic Evidence for Two Founding Populations of the Americas,” Nature 525 (2015): 104–8.
Figure 23. The possible migration routes for early speakers of Tai-Kadai, Austroasiatic, and Austronesian languages are drawn based on Fig. 2 of J. Diamond and P. Bellwood, “Farmers and Their Languages: The First Expansions,” Science 300 (2003): 597–603.
Figure 24. The ancient shoreline in panel (1) approximates the map in A. Cooper and C. Stringer, “Did the Denisovans Cross Wallace’s Line?” Science 342 (2013): 321–23.
Figure 25. This illustration is based on Fig. 3D of P. Skoglund et al., “Reconstructing Prehistoric African Population Structure,” Cell 171 (2017): 59–71.
Figure 26. The African language family contours approximate those shown in Fig. 3 of M. C. Campbell, J. B. Hirbo, J. P. Townsend, and S. A. Tishkoff, “The Peopling of the African Continent and the Diaspora into the New World,” Current Opinion in Genetics and Development 29 (2014): 120–32. Possible migratory routes associated with the Bantu expansion are similar to those in Campbell et al., “The Peopling of the African Continent,” but they also incorporate advice from Scott MacEachern and findings from subsequent genetic studies that suggest an expansion north of the tropical rainforest may not have contributed much of the ancestry of present-day Bantu speakers in East Africa (G. B. Busby et al., “Admixture into and Within Sub-Saharan Africa,” eLife 5 (2016): e15266, and E. Patin et al., “Dispersals and Genetic Adaptation of Bantu-Speaking Populations in Africa and North America,” Science 356 (2017): 543–46).
Figure 27. This illustration combines numbers from Fig. 2B and Fig. 2C of P. Skoglund et al., “Reconstructing Prehistoric African Population Structure,” Cell 171 (2017): 59–71.
Figure 28. Adapted with permission from Fig. 2 of M. Karmin et al., “A Recent Bottleneck of Y Chromosome Diversity Coincides with a Global Change in Culture,” Genome Research 25 (2015): 459–66.