As climate change alters the temporal and geographic distribution of disease vectors, the prevention of mosquito-borne illnesses such as malaria stands to be complicated by shifting ecological factors. Gene drives – DNA sequences that spread through a population at higher frequencies than Mendelian inheritance patterns, even without bestowing a fitness advantage on their carriers – furnish a promising mechanism for vector control even under a changing climate. Gene drives also circumvent issues stymieing current prevention practices, such as growing insecticide resistance. Novel constructs have been engineered that render mosquito disease vectors incapable of carrying the malarial parasite Plasmodium falciparum. However, the dynamics of such mosquitoes cannot yet be tested in the wild. Computational models furnish a cost-effective and safe precursor to semi-field trials, allowing scientists to probe the potential environmental sensitivities and ecological interactions produced by this genetic technology. I develop a differential equation meta-population model, parameterized with empirical genetic and ecological data, to study the effect that specific environmental shocks – for example, sudden or prolonged temperature increases – have on the spread and fixation of novel genetic material in wild type mosquito populations.
Results/Conclusions
It is crucial to examine the ecological implications of gene drive, including by assessing the potential population dynamics among interacting genetic strains of mosquitoes under climatic stressors. Carriers of novel genetic constructs exhibit differences in biological fitness when compared to wild type organisms; their responses to environmental fluctuation will affect the speed of spread and fixation probability of the genetic material they carry. My meta-population model flexibly specifies a variety of potential functional forms to characterize the environmental sensitivity of Anopheles mosquitoes according to absolute temperature, variation in temperature, organisms’ genetic makeup, and organisms’ life cycle stage. Preliminary results indicate that the dynamics of mosquitoes carrying novel genetic material are highly sensitive to assumptions of both absolute temperature change and the functional form of biological response, with relative sensitivity levels affected significantly by mosquito life stage. Preliminary results also indicate that the life stage timing and assumed functional form of density dependent regulation is a strong lever in driving dynamics, affecting the consequent fixation of novel genetic constructs in a wild type population.