Table 2. List of parameters used in the SpaceMix models, along with their descriptions and priors.

$\overline{D}\left(G^{\left(obs\right)}\right)$ is the mean of the pairwise distances between observed locations G^(obs).

Parameter	Description	Prior
α0	controls the sill of the covariance matrix	α0 ∼ Exp(λ = 1/100)
α1	controls the rate of the decay of covariance with distance	α1 ∼ Exp(λ = 1)
α2	controls the shape of the decay of covariance with distance	α2 ∼ U(0.1,2)
ηk	the nugget in population k (population specific drift parameter)	ηk ∼ Exp(λ = 1)
Gk	the geogenetic location of population k	$G_k\sim \mathcal{N}(\mu =G_k^{\left(obs\right)},\sigma =\frac{1}{2}\overline{D}\left(G^{\left(obs\right)}\right))$
wk	the proportion of admixture in population k	2wk ∼ β(α = 1, β = 100)
${\mathit{G}}_{\mathit{k}}^{*}$	the geogenetic location of the source of admixture in population k	${G_k}^{*}\sim \mathcal{N}(\mu ={\overline{G}}^{\left(obs\right)},\sigma =2\overline{D}\left(G^{\left(obs\right)}\right))$