After 100 generations, what will the FST value likely be for toad populations separated by a highway?

FST is a measure of genetic differentiation among populations and can range from 0 to 1. It quantifies the fraction of total genetic variance that is due to population differentiation. When populations are completely isolated, FST approaches 1, indicating that they have developed distinct genetic identities. Conversely, if the populations are not differentiated genetically at all, FST approaches 0.

In the case of toad populations separated by a highway, if they have been isolated for 100 generations, we would expect them to experience limited gene flow due to the highway acting as a barrier. However, the degree of genetic differentiation would depend on the initial genetic diversity of the populations and how long they have been separated without interbreeding. Given a moderate level of isolation over 100 generations, it is plausible that some genetic differentiation will have occurred, but likely not to an extreme extent.

Thus, the FST value is likely close to 0, indicating some interbreeding still occurs or that they have not diverged extensively, but certainly more differentiation than FST equal to 0, which would suggest no differentiation at all.