a, Admixture graphs representing some of the topologies considered
for the two waves and one wave Out of Africa models assuming Denisovan
admixture. All topologies are identical except for the coloured lineages
representing Australo-Papuans (green), Neanderthal (Nea, orange) and
Denisovan (Den, blue). The graphs differ in (i) the number of OoA events,
and (ii) the number of Neanderthal admixture pulses. Png stands for
HGDP-Papuan. b, Sum of Squared Errors between the observed D-statistics and
the expectations for each quartet in the graph involving the chimpanzee as
an outgroup for each of the admixture graphs shown in a and the
corresponding four without Denisovan admixture. Each point is the result of
the optimization procedure with different starting points. See S09 for details. c,
MSMC analyses. Relative cross coalescence rate (CCR) estimates from
MSMC25 for pairs of individuals
including one African sample (Yoruba, Dinka and San) and one other sample
from Eurasia, as indicated in the legend. d, Simulation study to assess the
effect of archaic admixture on the CCR rates. Relative CCR estimated for
data simulated under a simple two population divergence model where one of
the populations admixed at different rates with an archaic population. See
S08 for
details.