[1] These evolving disease agents adapt to selective pressure introduced by treatment, allowing them to develop resistance to therapy, making it ineffective.
[2] Evolutionary therapy relies on the notion that Darwinian evolution is the main reason behind lethality of late stage cancer and multi-drug resistant bacterial infections such as methicillin-resistant Staphylococcus aureus.
These obstacles include high contingency of trajectory, speed of evolution, and inability to track the population state of disease over time.
Resistance to chemotherapy and molecularly targeted therapies is a major problem facing current cancer research.
Malignant cancers are dynamically evolving clades of cells living in distinct microhabitats that almost certainly ensure the emergence of therapy-resistant populations.
[20] Others imply that population control may be possible if resistance to therapy requires a substantial and costly phenotypic adaptation that reduces the organism's fitness.