Habitat fragmentation typically leads to smaller and more isolated populations, which can reduce genetic diversity and increase the risk of disease outbreaks.

Increased genetic diversity of hosts can actually reduce disease transmission by making it more difficult for pathogens to adapt to and infect a wide range of hosts.

Increased disease transmission can lead to reduced population sizes of host species, increased risk of disease spillover to new host species, and reduced genetic diversity of pathogens, all of which can contribute to decreased ecosystem stability.

Introducing non-native predators to control host populations can have unintended consequences, such as disrupting the food web and increasing the risk of disease transmission to new host species.

While habitat fragmentation can have indirect effects on the evolution of pathogens, such as by increasing the selection pressure for more transmissible pathogens, it is not a direct research topic in the field of habitat fragmentation and disease dynamics.