Table 1. Prior for all models.

θ_A, θ1, θ2 = effective mutation rate for the ancestral, river lamprey and brook lamprey populations respectively. M₁, M₂, M_Anc = Effective migration rate for the ancestral, river lamprey and brook lamprey populations respectively. τ = divergence time, τ_isolτ_sc divergence time under the ancient migration model and time of secondary contact respectively.

Parameters	Models	Prior
θA = 4NAncμ	SI, IM, AM, SC	Uniform [0–3]
θ1 = 4N1μ	SI, IM, AM, SC, PAN	Uniform [0–3]
θ2 = 4N2μ	SI, IM, AM, SC	Uniform [0–(θ1)]
M1 = M2 = 4N1m	IM, SC	Uniform [0–20]
MANC = 4N1m	AM	Uniform [0–20]
τ = 4N1t	SI, IM, AM, SC	Uniform [0–25]
τisol = 4N1t	AM	Uniform [0–τ]
τsc = 4N1t	SC	Uniform [0–τ]

Notes.

SI

strict isolation

IM

isolation with migration

AM

ancient migration

PAN

Panmixia

SC

secondary contact model