Example of dark matter halo growth calculated according to the model of Wechsler et al. (2002) (Eq. (2)) with the fits of McBride et al. (2009). Black, green, and red curves represent the mass evolution of a MW-type halo with M₀ = 1 × 10¹² M_⊙ as in Battaglia et al. (2005), a M31 halo with M₀ = 1.6 × 10¹² M_⊙ as in Klypin et al. (2002), and an object that will have the mass our Local Group of galaxies today: M₀ ~ 3 × 10¹² M_⊙ as in Klypin et al. (2002). For comparison, the blue dot stands for the mass of an MW-type halo at z = 9 as found in numerical simulation by Iliev et al. (2011).