How does evolution affect variation in range expansion?

09.04.2020
We now know, through experimental manipulation of evolution rates, that rapid evolution increases the speed of range expansion. However, these same experiments reveal that evolution also affects variation between replicate populations, sometimes increasing variation and other times decreasing variation. Informed by their CIEE working group discussions, Williams, Hufbauer and Miller suggest that ecological factors (e.g. population size, mating systems) alter the balance between selection and drift, causing variance to increase (drift dominates) or decrease (selection dominates).
https://doi.org/10.1016/j.tree.2019.05.012
We now know, through experimental manipulation of evolution rates, that rapid evolution increases the speed of range expansion. However, these same experiments reveal that evolution also affects variation between replicate populations, sometimes increasing variation and other times decreasing variation. Informed by their CIEE working group discussions, Williams, Hufbauer and Miller suggest that ecological factors (e.g. population size, mating systems) alter the balance between selection and drift, causing variance to increase (drift dominates) or decrease (selection dominates).
https://doi.org/10.1016/j.tree.2019.05.012