A decomposable branching process in a Markovian environment
  A population has two types of individuals, each occupying an island. One of those, where individuals of type 1 live, offers a variable environment. Type 2 individuals dwell on the other island, in a constant environment. Only one-way migration (1->2) is possible. We study the asymptotics of the survival probability in critical and subcritical cases. 
Vladimir Vatutin, Elena Dyakonova, Peter Jagers, and Serik Sagitov
math.PR q-bio.PE